diff --git a/vendor/google.golang.org/grpc/.travis.yml b/vendor/google.golang.org/grpc/.travis.yml
index a11e8cb..87f40b8 100644
--- a/vendor/google.golang.org/grpc/.travis.yml
+++ b/vendor/google.golang.org/grpc/.travis.yml
@@ -11,7 +11,7 @@
   - go: 1.13.x
     env: GRPC_GO_RETRY=on
   - go: 1.13.x
-    env: TESTEXTRAS=1
+    env: TESTEXAMPLES=1
   - go: 1.12.x
     env: GO111MODULE=on
   - go: 1.11.x
@@ -35,7 +35,7 @@
 
 script:
   - set -e
-  - if [[ -n "${TESTEXTRAS}" ]]; then examples/examples_test.sh; interop/interop_test.sh; make testsubmodule; exit 0; fi
+  - if [[ -n "${TESTEXAMPLES}" ]]; then examples/examples_test.sh; exit 0; fi
   - if [[ -n "${VET}" ]]; then ./vet.sh; fi
   - if [[ -n "${GAE}" ]]; then make testappengine; exit 0; fi
   - if [[ -n "${RACE}" ]]; then make testrace; exit 0; fi
diff --git a/vendor/google.golang.org/grpc/Makefile b/vendor/google.golang.org/grpc/Makefile
index 410f7d5..db982aa 100644
--- a/vendor/google.golang.org/grpc/Makefile
+++ b/vendor/google.golang.org/grpc/Makefile
@@ -19,9 +19,6 @@
 test: testdeps
 	go test -cpu 1,4 -timeout 7m google.golang.org/grpc/...
 
-testsubmodule: testdeps
-	cd security/advancedtls && go test -cpu 1,4 -timeout 7m google.golang.org/grpc/security/advancedtls/...
-
 testappengine: testappenginedeps
 	goapp test -cpu 1,4 -timeout 7m google.golang.org/grpc/...
 
diff --git a/vendor/google.golang.org/grpc/README.md b/vendor/google.golang.org/grpc/README.md
index 800e7bd..afbc43d 100644
--- a/vendor/google.golang.org/grpc/README.md
+++ b/vendor/google.golang.org/grpc/README.md
@@ -93,22 +93,6 @@
 
 #### Compiling error, undefined: grpc.SupportPackageIsVersion
 
-##### If you are using Go modules:
-
-Please ensure your gRPC-Go version is `require`d at the appropriate version in
-the same module containing the generated `.pb.go` files.  For example,
-`SupportPackageIsVersion6` needs `v1.27.0`, so in your `go.mod` file:
-
-```
-module <your module name>
-
-require (
-    google.golang.org/grpc v1.27.0
-)
-```
-
-##### If you are *not* using Go modules:
-
 Please update proto package, gRPC package and rebuild the proto files:
  - `go get -u github.com/golang/protobuf/{proto,protoc-gen-go}`
  - `go get -u google.golang.org/grpc`
@@ -130,10 +114,6 @@
  1. mis-configured transport credentials, connection failed on handshaking
  1. bytes disrupted, possibly by a proxy in between
  1. server shutdown
- 1. Keepalive parameters caused connection shutdown, for example if you have configured
-    your server to terminate connections regularly to [trigger DNS lookups](https://github.com/grpc/grpc-go/issues/3170#issuecomment-552517779).
-    If this is the case, you may want to increase your [MaxConnectionAgeGrace](https://pkg.go.dev/google.golang.org/grpc/keepalive?tab=doc#ServerParameters),
-    to allow longer RPC calls to finish.
 
 It can be tricky to debug this because the error happens on the client side but
 the root cause of the connection being closed is on the server side. Turn on
diff --git a/vendor/google.golang.org/grpc/attributes/attributes.go b/vendor/google.golang.org/grpc/attributes/attributes.go
deleted file mode 100644
index 68ffc62..0000000
--- a/vendor/google.golang.org/grpc/attributes/attributes.go
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- *
- * Copyright 2019 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-// Package attributes defines a generic key/value store used in various gRPC
-// components.
-//
-// All APIs in this package are EXPERIMENTAL.
-package attributes
-
-import "fmt"
-
-// Attributes is an immutable struct for storing and retrieving generic
-// key/value pairs.  Keys must be hashable, and users should define their own
-// types for keys.
-type Attributes struct {
-	m map[interface{}]interface{}
-}
-
-// New returns a new Attributes containing all key/value pairs in kvs.  If the
-// same key appears multiple times, the last value overwrites all previous
-// values for that key.  Panics if len(kvs) is not even.
-func New(kvs ...interface{}) *Attributes {
-	if len(kvs)%2 != 0 {
-		panic(fmt.Sprintf("attributes.New called with unexpected input: len(kvs) = %v", len(kvs)))
-	}
-	a := &Attributes{m: make(map[interface{}]interface{}, len(kvs)/2)}
-	for i := 0; i < len(kvs)/2; i++ {
-		a.m[kvs[i*2]] = kvs[i*2+1]
-	}
-	return a
-}
-
-// WithValues returns a new Attributes containing all key/value pairs in a and
-// kvs.  Panics if len(kvs) is not even.  If the same key appears multiple
-// times, the last value overwrites all previous values for that key.  To
-// remove an existing key, use a nil value.
-func (a *Attributes) WithValues(kvs ...interface{}) *Attributes {
-	if len(kvs)%2 != 0 {
-		panic(fmt.Sprintf("attributes.New called with unexpected input: len(kvs) = %v", len(kvs)))
-	}
-	n := &Attributes{m: make(map[interface{}]interface{}, len(a.m)+len(kvs)/2)}
-	for k, v := range a.m {
-		n.m[k] = v
-	}
-	for i := 0; i < len(kvs)/2; i++ {
-		n.m[kvs[i*2]] = kvs[i*2+1]
-	}
-	return n
-}
-
-// Value returns the value associated with these attributes for key, or nil if
-// no value is associated with key.
-func (a *Attributes) Value(key interface{}) interface{} {
-	return a.m[key]
-}
diff --git a/vendor/google.golang.org/grpc/balancer/balancer.go b/vendor/google.golang.org/grpc/balancer/balancer.go
index 9258858..917c242 100644
--- a/vendor/google.golang.org/grpc/balancer/balancer.go
+++ b/vendor/google.golang.org/grpc/balancer/balancer.go
@@ -117,15 +117,6 @@
 	HealthCheckEnabled bool
 }
 
-// State contains the balancer's state relevant to the gRPC ClientConn.
-type State struct {
-	// State contains the connectivity state of the balancer, which is used to
-	// determine the state of the ClientConn.
-	ConnectivityState connectivity.State
-	// Picker is used to choose connections (SubConns) for RPCs.
-	Picker V2Picker
-}
-
 // ClientConn represents a gRPC ClientConn.
 //
 // This interface is to be implemented by gRPC. Users should not need a
@@ -146,19 +137,10 @@
 	//
 	// gRPC will update the connectivity state of the ClientConn, and will call pick
 	// on the new picker to pick new SubConn.
-	//
-	// Deprecated: use UpdateState instead
 	UpdateBalancerState(s connectivity.State, p Picker)
 
-	// UpdateState notifies gRPC that the balancer's internal state has
-	// changed.
-	//
-	// gRPC will update the connectivity state of the ClientConn, and will call pick
-	// on the new picker to pick new SubConns.
-	UpdateState(State)
-
 	// ResolveNow is called by balancer to notify gRPC to do a name resolving.
-	ResolveNow(resolver.ResolveNowOptions)
+	ResolveNow(resolver.ResolveNowOption)
 
 	// Target returns the dial target for this ClientConn.
 	//
@@ -203,14 +185,11 @@
 	ParseConfig(LoadBalancingConfigJSON json.RawMessage) (serviceconfig.LoadBalancingConfig, error)
 }
 
-// PickInfo contains additional information for the Pick operation.
-type PickInfo struct {
+// PickOptions contains addition information for the Pick operation.
+type PickOptions struct {
 	// FullMethodName is the method name that NewClientStream() is called
 	// with. The canonical format is /service/Method.
 	FullMethodName string
-	// Ctx is the RPC's context, and may contain relevant RPC-level information
-	// like the outgoing header metadata.
-	Ctx context.Context
 }
 
 // DoneInfo contains additional information for done.
@@ -236,7 +215,7 @@
 	ErrNoSubConnAvailable = errors.New("no SubConn is available")
 	// ErrTransientFailure indicates all SubConns are in TransientFailure.
 	// WaitForReady RPCs will block, non-WaitForReady RPCs will fail.
-	ErrTransientFailure = TransientFailureError(errors.New("all SubConns are in TransientFailure"))
+	ErrTransientFailure = errors.New("all SubConns are in TransientFailure")
 )
 
 // Picker is used by gRPC to pick a SubConn to send an RPC.
@@ -244,8 +223,6 @@
 // internal state has changed.
 //
 // The pickers used by gRPC can be updated by ClientConn.UpdateBalancerState().
-//
-// Deprecated: use V2Picker instead
 type Picker interface {
 	// Pick returns the SubConn to be used to send the RPC.
 	// The returned SubConn must be one returned by NewSubConn().
@@ -266,76 +243,18 @@
 	//
 	// If the returned error is not nil:
 	// - If the error is ErrNoSubConnAvailable, gRPC will block until UpdateBalancerState()
-	// - If the error is ErrTransientFailure or implements IsTransientFailure()
-	//   bool, returning true:
+	// - If the error is ErrTransientFailure:
 	//   - If the RPC is wait-for-ready, gRPC will block until UpdateBalancerState()
 	//     is called to pick again;
 	//   - Otherwise, RPC will fail with unavailable error.
 	// - Else (error is other non-nil error):
-	//   - The RPC will fail with the error's status code, or Unknown if it is
-	//     not a status error.
+	//   - The RPC will fail with unavailable error.
 	//
 	// The returned done() function will be called once the rpc has finished,
 	// with the final status of that RPC.  If the SubConn returned is not a
 	// valid SubConn type, done may not be called.  done may be nil if balancer
 	// doesn't care about the RPC status.
-	Pick(ctx context.Context, info PickInfo) (conn SubConn, done func(DoneInfo), err error)
-}
-
-// PickResult contains information related to a connection chosen for an RPC.
-type PickResult struct {
-	// SubConn is the connection to use for this pick, if its state is Ready.
-	// If the state is not Ready, gRPC will block the RPC until a new Picker is
-	// provided by the balancer (using ClientConn.UpdateState).  The SubConn
-	// must be one returned by ClientConn.NewSubConn.
-	SubConn SubConn
-
-	// Done is called when the RPC is completed.  If the SubConn is not ready,
-	// this will be called with a nil parameter.  If the SubConn is not a valid
-	// type, Done may not be called.  May be nil if the balancer does not wish
-	// to be notified when the RPC completes.
-	Done func(DoneInfo)
-}
-
-type transientFailureError struct {
-	error
-}
-
-func (e *transientFailureError) IsTransientFailure() bool { return true }
-
-// TransientFailureError wraps err in an error implementing
-// IsTransientFailure() bool, returning true.
-func TransientFailureError(err error) error {
-	return &transientFailureError{error: err}
-}
-
-// V2Picker is used by gRPC to pick a SubConn to send an RPC.
-// Balancer is expected to generate a new picker from its snapshot every time its
-// internal state has changed.
-//
-// The pickers used by gRPC can be updated by ClientConn.UpdateBalancerState().
-type V2Picker interface {
-	// Pick returns the connection to use for this RPC and related information.
-	//
-	// Pick should not block.  If the balancer needs to do I/O or any blocking
-	// or time-consuming work to service this call, it should return
-	// ErrNoSubConnAvailable, and the Pick call will be repeated by gRPC when
-	// the Picker is updated (using ClientConn.UpdateState).
-	//
-	// If an error is returned:
-	//
-	// - If the error is ErrNoSubConnAvailable, gRPC will block until a new
-	//   Picker is provided by the balancer (using ClientConn.UpdateState).
-	//
-	// - If the error implements IsTransientFailure() bool, returning true,
-	//   wait for ready RPCs will wait, but non-wait for ready RPCs will be
-	//   terminated with this error's Error() string and status code
-	//   Unavailable.
-	//
-	// - Any other errors terminate all RPCs with the code and message
-	//   provided.  If the error is not a status error, it will be converted by
-	//   gRPC to a status error with code Unknown.
-	Pick(info PickInfo) (PickResult, error)
+	Pick(ctx context.Context, opts PickOptions) (conn SubConn, done func(DoneInfo), err error)
 }
 
 // Balancer takes input from gRPC, manages SubConns, and collects and aggregates
@@ -373,11 +292,8 @@
 
 // SubConnState describes the state of a SubConn.
 type SubConnState struct {
-	// ConnectivityState is the connectivity state of the SubConn.
 	ConnectivityState connectivity.State
-	// ConnectionError is set if the ConnectivityState is TransientFailure,
-	// describing the reason the SubConn failed.  Otherwise, it is nil.
-	ConnectionError error
+	// TODO: add last connection error
 }
 
 // ClientConnState describes the state of a ClientConn relevant to the
@@ -419,8 +335,9 @@
 //
 // It's not thread safe.
 type ConnectivityStateEvaluator struct {
-	numReady      uint64 // Number of addrConns in ready state.
-	numConnecting uint64 // Number of addrConns in connecting state.
+	numReady            uint64 // Number of addrConns in ready state.
+	numConnecting       uint64 // Number of addrConns in connecting state.
+	numTransientFailure uint64 // Number of addrConns in transientFailure.
 }
 
 // RecordTransition records state change happening in subConn and based on that
@@ -440,6 +357,8 @@
 			cse.numReady += updateVal
 		case connectivity.Connecting:
 			cse.numConnecting += updateVal
+		case connectivity.TransientFailure:
+			cse.numTransientFailure += updateVal
 		}
 	}
 
diff --git a/vendor/google.golang.org/grpc/balancer/base/balancer.go b/vendor/google.golang.org/grpc/balancer/base/balancer.go
index 80559b8..1a5c1aa 100644
--- a/vendor/google.golang.org/grpc/balancer/base/balancer.go
+++ b/vendor/google.golang.org/grpc/balancer/base/balancer.go
@@ -20,8 +20,6 @@
 
 import (
 	"context"
-	"errors"
-	"fmt"
 
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/connectivity"
@@ -30,32 +28,25 @@
 )
 
 type baseBuilder struct {
-	name            string
-	pickerBuilder   PickerBuilder
-	v2PickerBuilder V2PickerBuilder
-	config          Config
+	name          string
+	pickerBuilder PickerBuilder
+	config        Config
 }
 
 func (bb *baseBuilder) Build(cc balancer.ClientConn, opt balancer.BuildOptions) balancer.Balancer {
-	bal := &baseBalancer{
-		cc:              cc,
-		pickerBuilder:   bb.pickerBuilder,
-		v2PickerBuilder: bb.v2PickerBuilder,
+	return &baseBalancer{
+		cc:            cc,
+		pickerBuilder: bb.pickerBuilder,
 
 		subConns: make(map[resolver.Address]balancer.SubConn),
 		scStates: make(map[balancer.SubConn]connectivity.State),
 		csEvltr:  &balancer.ConnectivityStateEvaluator{},
-		config:   bb.config,
+		// Initialize picker to a picker that always return
+		// ErrNoSubConnAvailable, because when state of a SubConn changes, we
+		// may call UpdateBalancerState with this picker.
+		picker: NewErrPicker(balancer.ErrNoSubConnAvailable),
+		config: bb.config,
 	}
-	// Initialize picker to a picker that always returns
-	// ErrNoSubConnAvailable, because when state of a SubConn changes, we
-	// may call UpdateState with this picker.
-	if bb.pickerBuilder != nil {
-		bal.picker = NewErrPicker(balancer.ErrNoSubConnAvailable)
-	} else {
-		bal.v2Picker = NewErrPickerV2(balancer.ErrNoSubConnAvailable)
-	}
-	return bal
 }
 
 func (bb *baseBuilder) Name() string {
@@ -65,9 +56,8 @@
 var _ balancer.V2Balancer = (*baseBalancer)(nil) // Assert that we implement V2Balancer
 
 type baseBalancer struct {
-	cc              balancer.ClientConn
-	pickerBuilder   PickerBuilder
-	v2PickerBuilder V2PickerBuilder
+	cc            balancer.ClientConn
+	pickerBuilder PickerBuilder
 
 	csEvltr *balancer.ConnectivityStateEvaluator
 	state   connectivity.State
@@ -75,36 +65,15 @@
 	subConns map[resolver.Address]balancer.SubConn
 	scStates map[balancer.SubConn]connectivity.State
 	picker   balancer.Picker
-	v2Picker balancer.V2Picker
 	config   Config
-
-	resolverErr error // the last error reported by the resolver; cleared on successful resolution
-	connErr     error // the last connection error; cleared upon leaving TransientFailure
 }
 
 func (b *baseBalancer) HandleResolvedAddrs(addrs []resolver.Address, err error) {
 	panic("not implemented")
 }
 
-func (b *baseBalancer) ResolverError(err error) {
-	b.resolverErr = err
-	if len(b.subConns) == 0 {
-		b.state = connectivity.TransientFailure
-	}
-	if b.state != connectivity.TransientFailure {
-		// The picker will not change since the balancer does not currently
-		// report an error.
-		return
-	}
-	b.regeneratePicker()
-	if b.picker != nil {
-		b.cc.UpdateBalancerState(b.state, b.picker)
-	} else {
-		b.cc.UpdateState(balancer.State{
-			ConnectivityState: b.state,
-			Picker:            b.v2Picker,
-		})
-	}
+func (b *baseBalancer) ResolverError(error) {
+	// Ignore
 }
 
 func (b *baseBalancer) UpdateClientConnState(s balancer.ClientConnState) error {
@@ -113,8 +82,6 @@
 	if grpclog.V(2) {
 		grpclog.Infoln("base.baseBalancer: got new ClientConn state: ", s)
 	}
-	// Successful resolution; clear resolver error and ensure we return nil.
-	b.resolverErr = nil
 	// addrsSet is the set converted from addrs, it's used for quick lookup of an address.
 	addrsSet := make(map[resolver.Address]struct{})
 	for _, a := range s.ResolverState.Addresses {
@@ -140,65 +107,27 @@
 			// The entry will be deleted in HandleSubConnStateChange.
 		}
 	}
-	// If resolver state contains no addresses, return an error so ClientConn
-	// will trigger re-resolve. Also records this as an resolver error, so when
-	// the overall state turns transient failure, the error message will have
-	// the zero address information.
-	if len(s.ResolverState.Addresses) == 0 {
-		b.ResolverError(errors.New("produced zero addresses"))
-		return balancer.ErrBadResolverState
-	}
 	return nil
 }
 
-// mergeErrors builds an error from the last connection error and the last
-// resolver error.  Must only be called if b.state is TransientFailure.
-func (b *baseBalancer) mergeErrors() error {
-	// connErr must always be non-nil unless there are no SubConns, in which
-	// case resolverErr must be non-nil.
-	if b.connErr == nil {
-		return fmt.Errorf("last resolver error: %v", b.resolverErr)
-	}
-	if b.resolverErr == nil {
-		return fmt.Errorf("last connection error: %v", b.connErr)
-	}
-	return fmt.Errorf("last connection error: %v; last resolver error: %v", b.connErr, b.resolverErr)
-}
-
 // regeneratePicker takes a snapshot of the balancer, and generates a picker
 // from it. The picker is
-//  - errPicker if the balancer is in TransientFailure,
+//  - errPicker with ErrTransientFailure if the balancer is in TransientFailure,
 //  - built by the pickerBuilder with all READY SubConns otherwise.
 func (b *baseBalancer) regeneratePicker() {
 	if b.state == connectivity.TransientFailure {
-		if b.pickerBuilder != nil {
-			b.picker = NewErrPicker(balancer.ErrTransientFailure)
-		} else {
-			b.v2Picker = NewErrPickerV2(balancer.TransientFailureError(b.mergeErrors()))
-		}
+		b.picker = NewErrPicker(balancer.ErrTransientFailure)
 		return
 	}
-	if b.pickerBuilder != nil {
-		readySCs := make(map[resolver.Address]balancer.SubConn)
+	readySCs := make(map[resolver.Address]balancer.SubConn)
 
-		// Filter out all ready SCs from full subConn map.
-		for addr, sc := range b.subConns {
-			if st, ok := b.scStates[sc]; ok && st == connectivity.Ready {
-				readySCs[addr] = sc
-			}
+	// Filter out all ready SCs from full subConn map.
+	for addr, sc := range b.subConns {
+		if st, ok := b.scStates[sc]; ok && st == connectivity.Ready {
+			readySCs[addr] = sc
 		}
-		b.picker = b.pickerBuilder.Build(readySCs)
-	} else {
-		readySCs := make(map[balancer.SubConn]SubConnInfo)
-
-		// Filter out all ready SCs from full subConn map.
-		for addr, sc := range b.subConns {
-			if st, ok := b.scStates[sc]; ok && st == connectivity.Ready {
-				readySCs[sc] = SubConnInfo{Address: addr}
-			}
-		}
-		b.v2Picker = b.v2PickerBuilder.Build(PickerBuildInfo{ReadySCs: readySCs})
 	}
+	b.picker = b.pickerBuilder.Build(readySCs)
 }
 
 func (b *baseBalancer) HandleSubConnStateChange(sc balancer.SubConn, s connectivity.State) {
@@ -217,12 +146,6 @@
 		}
 		return
 	}
-	if oldS == connectivity.TransientFailure && s == connectivity.Connecting {
-		// Once a subconn enters TRANSIENT_FAILURE, ignore subsequent
-		// CONNECTING transitions to prevent the aggregated state from being
-		// always CONNECTING when many backends exist but are all down.
-		return
-	}
 	b.scStates[sc] = s
 	switch s {
 	case connectivity.Idle:
@@ -231,27 +154,22 @@
 		// When an address was removed by resolver, b called RemoveSubConn but
 		// kept the sc's state in scStates. Remove state for this sc here.
 		delete(b.scStates, sc)
-	case connectivity.TransientFailure:
-		// Save error to be reported via picker.
-		b.connErr = state.ConnectionError
 	}
 
+	oldAggrState := b.state
 	b.state = b.csEvltr.RecordTransition(oldS, s)
 
 	// Regenerate picker when one of the following happens:
-	//  - this sc entered or left ready
-	//  - the aggregated state of balancer is TransientFailure
-	//    (may need to update error message)
+	//  - this sc became ready from not-ready
+	//  - this sc became not-ready from ready
+	//  - the aggregated state of balancer became TransientFailure from non-TransientFailure
+	//  - the aggregated state of balancer became non-TransientFailure from TransientFailure
 	if (s == connectivity.Ready) != (oldS == connectivity.Ready) ||
-		b.state == connectivity.TransientFailure {
+		(b.state == connectivity.TransientFailure) != (oldAggrState == connectivity.TransientFailure) {
 		b.regeneratePicker()
 	}
 
-	if b.picker != nil {
-		b.cc.UpdateBalancerState(b.state, b.picker)
-	} else {
-		b.cc.UpdateState(balancer.State{ConnectivityState: b.state, Picker: b.v2Picker})
-	}
+	b.cc.UpdateBalancerState(b.state, b.picker)
 }
 
 // Close is a nop because base balancer doesn't have internal state to clean up,
@@ -268,19 +186,6 @@
 	err error // Pick() always returns this err.
 }
 
-func (p *errPicker) Pick(context.Context, balancer.PickInfo) (balancer.SubConn, func(balancer.DoneInfo), error) {
+func (p *errPicker) Pick(ctx context.Context, opts balancer.PickOptions) (balancer.SubConn, func(balancer.DoneInfo), error) {
 	return nil, nil, p.err
 }
-
-// NewErrPickerV2 returns a V2Picker that always returns err on Pick().
-func NewErrPickerV2(err error) balancer.V2Picker {
-	return &errPickerV2{err: err}
-}
-
-type errPickerV2 struct {
-	err error // Pick() always returns this err.
-}
-
-func (p *errPickerV2) Pick(info balancer.PickInfo) (balancer.PickResult, error) {
-	return balancer.PickResult{}, p.err
-}
diff --git a/vendor/google.golang.org/grpc/balancer/base/base.go b/vendor/google.golang.org/grpc/balancer/base/base.go
index 4192918..34b1f29 100644
--- a/vendor/google.golang.org/grpc/balancer/base/base.go
+++ b/vendor/google.golang.org/grpc/balancer/base/base.go
@@ -42,26 +42,6 @@
 	Build(readySCs map[resolver.Address]balancer.SubConn) balancer.Picker
 }
 
-// V2PickerBuilder creates balancer.V2Picker.
-type V2PickerBuilder interface {
-	// Build returns a picker that will be used by gRPC to pick a SubConn.
-	Build(info PickerBuildInfo) balancer.V2Picker
-}
-
-// PickerBuildInfo contains information needed by the picker builder to
-// construct a picker.
-type PickerBuildInfo struct {
-	// ReadySCs is a map from all ready SubConns to the Addresses used to
-	// create them.
-	ReadySCs map[balancer.SubConn]SubConnInfo
-}
-
-// SubConnInfo contains information about a SubConn created by the base
-// balancer.
-type SubConnInfo struct {
-	Address resolver.Address // the address used to create this SubConn
-}
-
 // NewBalancerBuilder returns a balancer builder. The balancers
 // built by this builder will use the picker builder to build pickers.
 func NewBalancerBuilder(name string, pb PickerBuilder) balancer.Builder {
@@ -82,12 +62,3 @@
 		config:        config,
 	}
 }
-
-// NewBalancerBuilderV2 returns a base balancer builder configured by the provided config.
-func NewBalancerBuilderV2(name string, pb V2PickerBuilder, config Config) balancer.Builder {
-	return &baseBuilder{
-		name:            name,
-		v2PickerBuilder: pb,
-		config:          config,
-	}
-}
diff --git a/vendor/google.golang.org/grpc/balancer/roundrobin/roundrobin.go b/vendor/google.golang.org/grpc/balancer/roundrobin/roundrobin.go
index d4d6455..29f7a4d 100644
--- a/vendor/google.golang.org/grpc/balancer/roundrobin/roundrobin.go
+++ b/vendor/google.golang.org/grpc/balancer/roundrobin/roundrobin.go
@@ -22,12 +22,14 @@
 package roundrobin
 
 import (
+	"context"
 	"sync"
 
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/balancer/base"
 	"google.golang.org/grpc/grpclog"
 	"google.golang.org/grpc/internal/grpcrand"
+	"google.golang.org/grpc/resolver"
 )
 
 // Name is the name of round_robin balancer.
@@ -35,7 +37,7 @@
 
 // newBuilder creates a new roundrobin balancer builder.
 func newBuilder() balancer.Builder {
-	return base.NewBalancerBuilderV2(Name, &rrPickerBuilder{}, base.Config{HealthCheck: true})
+	return base.NewBalancerBuilderWithConfig(Name, &rrPickerBuilder{}, base.Config{HealthCheck: true})
 }
 
 func init() {
@@ -44,13 +46,13 @@
 
 type rrPickerBuilder struct{}
 
-func (*rrPickerBuilder) Build(info base.PickerBuildInfo) balancer.V2Picker {
-	grpclog.Infof("roundrobinPicker: newPicker called with info: %v", info)
-	if len(info.ReadySCs) == 0 {
-		return base.NewErrPickerV2(balancer.ErrNoSubConnAvailable)
+func (*rrPickerBuilder) Build(readySCs map[resolver.Address]balancer.SubConn) balancer.Picker {
+	grpclog.Infof("roundrobinPicker: newPicker called with readySCs: %v", readySCs)
+	if len(readySCs) == 0 {
+		return base.NewErrPicker(balancer.ErrNoSubConnAvailable)
 	}
 	var scs []balancer.SubConn
-	for sc := range info.ReadySCs {
+	for _, sc := range readySCs {
 		scs = append(scs, sc)
 	}
 	return &rrPicker{
@@ -72,10 +74,10 @@
 	next int
 }
 
-func (p *rrPicker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
+func (p *rrPicker) Pick(ctx context.Context, opts balancer.PickOptions) (balancer.SubConn, func(balancer.DoneInfo), error) {
 	p.mu.Lock()
 	sc := p.subConns[p.next]
 	p.next = (p.next + 1) % len(p.subConns)
 	p.mu.Unlock()
-	return balancer.PickResult{SubConn: sc}, nil
+	return sc, nil, nil
 }
diff --git a/vendor/google.golang.org/grpc/balancer_conn_wrappers.go b/vendor/google.golang.org/grpc/balancer_conn_wrappers.go
index f8667a2..5356194 100644
--- a/vendor/google.golang.org/grpc/balancer_conn_wrappers.go
+++ b/vendor/google.golang.org/grpc/balancer_conn_wrappers.go
@@ -24,8 +24,8 @@
 
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/grpclog"
 	"google.golang.org/grpc/internal/buffer"
-	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/grpcsync"
 	"google.golang.org/grpc/resolver"
 )
@@ -34,7 +34,6 @@
 type scStateUpdate struct {
 	sc    balancer.SubConn
 	state connectivity.State
-	err   error
 }
 
 // ccBalancerWrapper is a wrapper on top of cc for balancers.
@@ -75,7 +74,7 @@
 			ccb.balancerMu.Lock()
 			su := t.(*scStateUpdate)
 			if ub, ok := ccb.balancer.(balancer.V2Balancer); ok {
-				ub.UpdateSubConnState(su.sc, balancer.SubConnState{ConnectivityState: su.state, ConnectionError: su.err})
+				ub.UpdateSubConnState(su.sc, balancer.SubConnState{ConnectivityState: su.state})
 			} else {
 				ccb.balancer.HandleSubConnStateChange(su.sc, su.state)
 			}
@@ -92,7 +91,7 @@
 			for acbw := range scs {
 				ccb.cc.removeAddrConn(acbw.getAddrConn(), errConnDrain)
 			}
-			ccb.UpdateState(balancer.State{ConnectivityState: connectivity.Connecting, Picker: nil})
+			ccb.UpdateBalancerState(connectivity.Connecting, nil)
 			return
 		}
 	}
@@ -102,7 +101,7 @@
 	ccb.done.Fire()
 }
 
-func (ccb *ccBalancerWrapper) handleSubConnStateChange(sc balancer.SubConn, s connectivity.State, err error) {
+func (ccb *ccBalancerWrapper) handleSubConnStateChange(sc balancer.SubConn, s connectivity.State) {
 	// When updating addresses for a SubConn, if the address in use is not in
 	// the new addresses, the old ac will be tearDown() and a new ac will be
 	// created. tearDown() generates a state change with Shutdown state, we
@@ -116,7 +115,6 @@
 	ccb.scBuffer.Put(&scStateUpdate{
 		sc:    sc,
 		state: s,
-		err:   err,
 	})
 }
 
@@ -188,22 +186,7 @@
 	ccb.cc.csMgr.updateState(s)
 }
 
-func (ccb *ccBalancerWrapper) UpdateState(s balancer.State) {
-	ccb.mu.Lock()
-	defer ccb.mu.Unlock()
-	if ccb.subConns == nil {
-		return
-	}
-	// Update picker before updating state.  Even though the ordering here does
-	// not matter, it can lead to multiple calls of Pick in the common start-up
-	// case where we wait for ready and then perform an RPC.  If the picker is
-	// updated later, we could call the "connecting" picker when the state is
-	// updated, and then call the "ready" picker after the picker gets updated.
-	ccb.cc.blockingpicker.updatePickerV2(s.Picker)
-	ccb.cc.csMgr.updateState(s.ConnectivityState)
-}
-
-func (ccb *ccBalancerWrapper) ResolveNow(o resolver.ResolveNowOptions) {
+func (ccb *ccBalancerWrapper) ResolveNow(o resolver.ResolveNowOption) {
 	ccb.cc.resolveNow(o)
 }
 
@@ -245,7 +228,7 @@
 
 		ac, err := cc.newAddrConn(addrs, opts)
 		if err != nil {
-			channelz.Warningf(acbw.ac.channelzID, "acBalancerWrapper: UpdateAddresses: failed to newAddrConn: %v", err)
+			grpclog.Warningf("acBalancerWrapper: UpdateAddresses: failed to newAddrConn: %v", err)
 			return
 		}
 		acbw.ac = ac
diff --git a/vendor/google.golang.org/grpc/balancer_v1_wrapper.go b/vendor/google.golang.org/grpc/balancer_v1_wrapper.go
index db04b08..66e9a44 100644
--- a/vendor/google.golang.org/grpc/balancer_v1_wrapper.go
+++ b/vendor/google.golang.org/grpc/balancer_v1_wrapper.go
@@ -19,6 +19,7 @@
 package grpc
 
 import (
+	"context"
 	"sync"
 
 	"google.golang.org/grpc/balancer"
@@ -48,7 +49,7 @@
 		csEvltr:    &balancer.ConnectivityStateEvaluator{},
 		state:      connectivity.Idle,
 	}
-	cc.UpdateState(balancer.State{ConnectivityState: connectivity.Idle, Picker: bw})
+	cc.UpdateBalancerState(connectivity.Idle, bw)
 	go bw.lbWatcher()
 	return bw
 }
@@ -242,7 +243,7 @@
 	if bw.state != sa {
 		bw.state = sa
 	}
-	bw.cc.UpdateState(balancer.State{ConnectivityState: bw.state, Picker: bw})
+	bw.cc.UpdateBalancerState(bw.state, bw)
 	if s == connectivity.Shutdown {
 		// Remove state for this sc.
 		delete(bw.connSt, sc)
@@ -274,17 +275,17 @@
 
 // The picker is the balancerWrapper itself.
 // It either blocks or returns error, consistent with v1 balancer Get().
-func (bw *balancerWrapper) Pick(info balancer.PickInfo) (result balancer.PickResult, err error) {
+func (bw *balancerWrapper) Pick(ctx context.Context, opts balancer.PickOptions) (sc balancer.SubConn, done func(balancer.DoneInfo), err error) {
 	failfast := true // Default failfast is true.
-	if ss, ok := rpcInfoFromContext(info.Ctx); ok {
+	if ss, ok := rpcInfoFromContext(ctx); ok {
 		failfast = ss.failfast
 	}
-	a, p, err := bw.balancer.Get(info.Ctx, BalancerGetOptions{BlockingWait: !failfast})
+	a, p, err := bw.balancer.Get(ctx, BalancerGetOptions{BlockingWait: !failfast})
 	if err != nil {
-		return balancer.PickResult{}, toRPCErr(err)
+		return nil, nil, err
 	}
 	if p != nil {
-		result.Done = func(balancer.DoneInfo) { p() }
+		done = func(balancer.DoneInfo) { p() }
 		defer func() {
 			if err != nil {
 				p()
@@ -296,39 +297,38 @@
 	defer bw.mu.Unlock()
 	if bw.pickfirst {
 		// Get the first sc in conns.
-		for _, result.SubConn = range bw.conns {
-			return result, nil
+		for _, sc := range bw.conns {
+			return sc, done, nil
 		}
-		return balancer.PickResult{}, balancer.ErrNoSubConnAvailable
+		return nil, nil, balancer.ErrNoSubConnAvailable
 	}
-	var ok1 bool
-	result.SubConn, ok1 = bw.conns[resolver.Address{
+	sc, ok1 := bw.conns[resolver.Address{
 		Addr:       a.Addr,
 		Type:       resolver.Backend,
 		ServerName: "",
 		Metadata:   a.Metadata,
 	}]
-	s, ok2 := bw.connSt[result.SubConn]
+	s, ok2 := bw.connSt[sc]
 	if !ok1 || !ok2 {
 		// This can only happen due to a race where Get() returned an address
 		// that was subsequently removed by Notify.  In this case we should
 		// retry always.
-		return balancer.PickResult{}, balancer.ErrNoSubConnAvailable
+		return nil, nil, balancer.ErrNoSubConnAvailable
 	}
 	switch s.s {
 	case connectivity.Ready, connectivity.Idle:
-		return result, nil
+		return sc, done, nil
 	case connectivity.Shutdown, connectivity.TransientFailure:
 		// If the returned sc has been shut down or is in transient failure,
 		// return error, and this RPC will fail or wait for another picker (if
 		// non-failfast).
-		return balancer.PickResult{}, balancer.ErrTransientFailure
+		return nil, nil, balancer.ErrTransientFailure
 	default:
 		// For other states (connecting or unknown), the v1 balancer would
 		// traditionally wait until ready and then issue the RPC.  Returning
 		// ErrNoSubConnAvailable will be a slight improvement in that it will
 		// allow the balancer to choose another address in case others are
 		// connected.
-		return balancer.PickResult{}, balancer.ErrNoSubConnAvailable
+		return nil, nil, balancer.ErrNoSubConnAvailable
 	}
 }
diff --git a/vendor/google.golang.org/grpc/clientconn.go b/vendor/google.golang.org/grpc/clientconn.go
index 0740693..4414ba8 100644
--- a/vendor/google.golang.org/grpc/clientconn.go
+++ b/vendor/google.golang.org/grpc/clientconn.go
@@ -35,10 +35,10 @@
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/grpclog"
 	"google.golang.org/grpc/internal/backoff"
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/grpcsync"
-	"google.golang.org/grpc/internal/grpcutil"
 	"google.golang.org/grpc/internal/transport"
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/resolver"
@@ -151,7 +151,7 @@
 	if channelz.IsOn() {
 		if cc.dopts.channelzParentID != 0 {
 			cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, cc.dopts.channelzParentID, target)
-			channelz.AddTraceEvent(cc.channelzID, 0, &channelz.TraceEventDesc{
+			channelz.AddTraceEvent(cc.channelzID, &channelz.TraceEventDesc{
 				Desc:     "Channel Created",
 				Severity: channelz.CtINFO,
 				Parent: &channelz.TraceEventDesc{
@@ -161,7 +161,10 @@
 			})
 		} else {
 			cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, 0, target)
-			channelz.Info(cc.channelzID, "Channel Created")
+			channelz.AddTraceEvent(cc.channelzID, &channelz.TraceEventDesc{
+				Desc:     "Channel Created",
+				Severity: channelz.CtINFO,
+			})
 		}
 		cc.csMgr.channelzID = cc.channelzID
 	}
@@ -194,13 +197,12 @@
 	cc.mkp = cc.dopts.copts.KeepaliveParams
 
 	if cc.dopts.copts.Dialer == nil {
-		cc.dopts.copts.Dialer = func(ctx context.Context, addr string) (net.Conn, error) {
-			network, addr := parseDialTarget(addr)
-			return (&net.Dialer{}).DialContext(ctx, network, addr)
-		}
-		if cc.dopts.withProxy {
-			cc.dopts.copts.Dialer = newProxyDialer(cc.dopts.copts.Dialer)
-		}
+		cc.dopts.copts.Dialer = newProxyDialer(
+			func(ctx context.Context, addr string) (net.Conn, error) {
+				network, addr := parseDialTarget(addr)
+				return (&net.Dialer{}).DialContext(ctx, network, addr)
+			},
+		)
 	}
 
 	if cc.dopts.copts.UserAgent != "" {
@@ -237,26 +239,25 @@
 	if cc.dopts.bs == nil {
 		cc.dopts.bs = backoff.DefaultExponential
 	}
-
-	// Determine the resolver to use.
-	cc.parsedTarget = grpcutil.ParseTarget(cc.target)
-	channelz.Infof(cc.channelzID, "parsed scheme: %q", cc.parsedTarget.Scheme)
-	resolverBuilder := cc.getResolver(cc.parsedTarget.Scheme)
-	if resolverBuilder == nil {
-		// If resolver builder is still nil, the parsed target's scheme is
-		// not registered. Fallback to default resolver and set Endpoint to
-		// the original target.
-		channelz.Infof(cc.channelzID, "scheme %q not registered, fallback to default scheme", cc.parsedTarget.Scheme)
-		cc.parsedTarget = resolver.Target{
-			Scheme:   resolver.GetDefaultScheme(),
-			Endpoint: target,
+	if cc.dopts.resolverBuilder == nil {
+		// Only try to parse target when resolver builder is not already set.
+		cc.parsedTarget = parseTarget(cc.target)
+		grpclog.Infof("parsed scheme: %q", cc.parsedTarget.Scheme)
+		cc.dopts.resolverBuilder = resolver.Get(cc.parsedTarget.Scheme)
+		if cc.dopts.resolverBuilder == nil {
+			// If resolver builder is still nil, the parsed target's scheme is
+			// not registered. Fallback to default resolver and set Endpoint to
+			// the original target.
+			grpclog.Infof("scheme %q not registered, fallback to default scheme", cc.parsedTarget.Scheme)
+			cc.parsedTarget = resolver.Target{
+				Scheme:   resolver.GetDefaultScheme(),
+				Endpoint: target,
+			}
+			cc.dopts.resolverBuilder = resolver.Get(cc.parsedTarget.Scheme)
 		}
-		resolverBuilder = cc.getResolver(cc.parsedTarget.Scheme)
-		if resolverBuilder == nil {
-			return nil, fmt.Errorf("could not get resolver for default scheme: %q", cc.parsedTarget.Scheme)
-		}
+	} else {
+		cc.parsedTarget = resolver.Target{Endpoint: target}
 	}
-
 	creds := cc.dopts.copts.TransportCredentials
 	if creds != nil && creds.Info().ServerName != "" {
 		cc.authority = creds.Info().ServerName
@@ -296,14 +297,14 @@
 	}
 
 	// Build the resolver.
-	rWrapper, err := newCCResolverWrapper(cc, resolverBuilder)
+	rWrapper, err := newCCResolverWrapper(cc)
 	if err != nil {
 		return nil, fmt.Errorf("failed to build resolver: %v", err)
 	}
+
 	cc.mu.Lock()
 	cc.resolverWrapper = rWrapper
 	cc.mu.Unlock()
-
 	// A blocking dial blocks until the clientConn is ready.
 	if cc.dopts.block {
 		for {
@@ -414,7 +415,12 @@
 		return
 	}
 	csm.state = state
-	channelz.Infof(csm.channelzID, "Channel Connectivity change to %v", state)
+	if channelz.IsOn() {
+		channelz.AddTraceEvent(csm.channelzID, &channelz.TraceEventDesc{
+			Desc:     fmt.Sprintf("Channel Connectivity change to %v", state),
+			Severity: channelz.CtINFO,
+		})
+	}
 	if csm.notifyChan != nil {
 		// There are other goroutines waiting on this channel.
 		close(csm.notifyChan)
@@ -437,20 +443,6 @@
 	return csm.notifyChan
 }
 
-// ClientConnInterface defines the functions clients need to perform unary and
-// streaming RPCs.  It is implemented by *ClientConn, and is only intended to
-// be referenced by generated code.
-type ClientConnInterface interface {
-	// Invoke performs a unary RPC and returns after the response is received
-	// into reply.
-	Invoke(ctx context.Context, method string, args interface{}, reply interface{}, opts ...CallOption) error
-	// NewStream begins a streaming RPC.
-	NewStream(ctx context.Context, desc *StreamDesc, method string, opts ...CallOption) (ClientStream, error)
-}
-
-// Assert *ClientConn implements ClientConnInterface.
-var _ ClientConnInterface = (*ClientConn)(nil)
-
 // ClientConn represents a virtual connection to a conceptual endpoint, to
 // perform RPCs.
 //
@@ -664,9 +656,9 @@
 		return
 	}
 
-	channelz.Infof(cc.channelzID, "ClientConn switching balancer to %q", name)
+	grpclog.Infof("ClientConn switching balancer to %q", name)
 	if cc.dopts.balancerBuilder != nil {
-		channelz.Info(cc.channelzID, "ignoring balancer switching: Balancer DialOption used instead")
+		grpclog.Infoln("ignoring balancer switching: Balancer DialOption used instead")
 		return
 	}
 	if cc.balancerWrapper != nil {
@@ -674,19 +666,29 @@
 	}
 
 	builder := balancer.Get(name)
+	if channelz.IsOn() {
+		if builder == nil {
+			channelz.AddTraceEvent(cc.channelzID, &channelz.TraceEventDesc{
+				Desc:     fmt.Sprintf("Channel switches to new LB policy %q due to fallback from invalid balancer name", PickFirstBalancerName),
+				Severity: channelz.CtWarning,
+			})
+		} else {
+			channelz.AddTraceEvent(cc.channelzID, &channelz.TraceEventDesc{
+				Desc:     fmt.Sprintf("Channel switches to new LB policy %q", name),
+				Severity: channelz.CtINFO,
+			})
+		}
+	}
 	if builder == nil {
-		channelz.Warningf(cc.channelzID, "Channel switches to new LB policy %q due to fallback from invalid balancer name", PickFirstBalancerName)
-		channelz.Infof(cc.channelzID, "failed to get balancer builder for: %v, using pick_first instead", name)
+		grpclog.Infof("failed to get balancer builder for: %v, using pick_first instead", name)
 		builder = newPickfirstBuilder()
-	} else {
-		channelz.Infof(cc.channelzID, "Channel switches to new LB policy %q", name)
 	}
 
 	cc.curBalancerName = builder.Name()
 	cc.balancerWrapper = newCCBalancerWrapper(cc, builder, cc.balancerBuildOpts)
 }
 
-func (cc *ClientConn) handleSubConnStateChange(sc balancer.SubConn, s connectivity.State, err error) {
+func (cc *ClientConn) handleSubConnStateChange(sc balancer.SubConn, s connectivity.State) {
 	cc.mu.Lock()
 	if cc.conns == nil {
 		cc.mu.Unlock()
@@ -694,7 +696,7 @@
 	}
 	// TODO(bar switching) send updates to all balancer wrappers when balancer
 	// gracefully switching is supported.
-	cc.balancerWrapper.handleSubConnStateChange(sc, s, err)
+	cc.balancerWrapper.handleSubConnStateChange(sc, s)
 	cc.mu.Unlock()
 }
 
@@ -703,7 +705,6 @@
 // Caller needs to make sure len(addrs) > 0.
 func (cc *ClientConn) newAddrConn(addrs []resolver.Address, opts balancer.NewSubConnOptions) (*addrConn, error) {
 	ac := &addrConn{
-		state:        connectivity.Idle,
 		cc:           cc,
 		addrs:        addrs,
 		scopts:       opts,
@@ -720,7 +721,7 @@
 	}
 	if channelz.IsOn() {
 		ac.channelzID = channelz.RegisterSubChannel(ac, cc.channelzID, "")
-		channelz.AddTraceEvent(ac.channelzID, 0, &channelz.TraceEventDesc{
+		channelz.AddTraceEvent(ac.channelzID, &channelz.TraceEventDesc{
 			Desc:     "Subchannel Created",
 			Severity: channelz.CtINFO,
 			Parent: &channelz.TraceEventDesc{
@@ -792,7 +793,7 @@
 	}
 	// Update connectivity state within the lock to prevent subsequent or
 	// concurrent calls from resetting the transport more than once.
-	ac.updateConnectivityState(connectivity.Connecting, nil)
+	ac.updateConnectivityState(connectivity.Connecting)
 	ac.mu.Unlock()
 
 	// Start a goroutine connecting to the server asynchronously.
@@ -818,7 +819,7 @@
 func (ac *addrConn) tryUpdateAddrs(addrs []resolver.Address) bool {
 	ac.mu.Lock()
 	defer ac.mu.Unlock()
-	channelz.Infof(ac.channelzID, "addrConn: tryUpdateAddrs curAddr: %v, addrs: %v", ac.curAddr, addrs)
+	grpclog.Infof("addrConn: tryUpdateAddrs curAddr: %v, addrs: %v", ac.curAddr, addrs)
 	if ac.state == connectivity.Shutdown ||
 		ac.state == connectivity.TransientFailure ||
 		ac.state == connectivity.Idle {
@@ -838,7 +839,7 @@
 			break
 		}
 	}
-	channelz.Infof(ac.channelzID, "addrConn: tryUpdateAddrs curAddrFound: %v", curAddrFound)
+	grpclog.Infof("addrConn: tryUpdateAddrs curAddrFound: %v", curAddrFound)
 	if curAddrFound {
 		ac.addrs = addrs
 	}
@@ -878,8 +879,7 @@
 }
 
 func (cc *ClientConn) getTransport(ctx context.Context, failfast bool, method string) (transport.ClientTransport, func(balancer.DoneInfo), error) {
-	t, done, err := cc.blockingpicker.pick(ctx, failfast, balancer.PickInfo{
-		Ctx:            ctx,
+	t, done, err := cc.blockingpicker.pick(ctx, failfast, balancer.PickOptions{
 		FullMethodName: method,
 	})
 	if err != nil {
@@ -938,7 +938,7 @@
 	}
 }
 
-func (cc *ClientConn) resolveNow(o resolver.ResolveNowOptions) {
+func (cc *ClientConn) resolveNow(o resolver.ResolveNowOption) {
 	cc.mu.RLock()
 	r := cc.resolverWrapper
 	cc.mu.RUnlock()
@@ -1009,7 +1009,7 @@
 				Severity: channelz.CtINFO,
 			}
 		}
-		channelz.AddTraceEvent(cc.channelzID, 0, ted)
+		channelz.AddTraceEvent(cc.channelzID, ted)
 		// TraceEvent needs to be called before RemoveEntry, as TraceEvent may add trace reference to
 		// the entity being deleted, and thus prevent it from being deleted right away.
 		channelz.RemoveEntry(cc.channelzID)
@@ -1048,13 +1048,20 @@
 }
 
 // Note: this requires a lock on ac.mu.
-func (ac *addrConn) updateConnectivityState(s connectivity.State, lastErr error) {
+func (ac *addrConn) updateConnectivityState(s connectivity.State) {
 	if ac.state == s {
 		return
 	}
+
+	updateMsg := fmt.Sprintf("Subchannel Connectivity change to %v", s)
 	ac.state = s
-	channelz.Infof(ac.channelzID, "Subchannel Connectivity change to %v", s)
-	ac.cc.handleSubConnStateChange(ac.acbw, s, lastErr)
+	if channelz.IsOn() {
+		channelz.AddTraceEvent(ac.channelzID, &channelz.TraceEventDesc{
+			Desc:     updateMsg,
+			Severity: channelz.CtINFO,
+		})
+	}
+	ac.cc.handleSubConnStateChange(ac.acbw, s)
 }
 
 // adjustParams updates parameters used to create transports upon
@@ -1074,7 +1081,7 @@
 func (ac *addrConn) resetTransport() {
 	for i := 0; ; i++ {
 		if i > 0 {
-			ac.cc.resolveNow(resolver.ResolveNowOptions{})
+			ac.cc.resolveNow(resolver.ResolveNowOption{})
 		}
 
 		ac.mu.Lock()
@@ -1103,7 +1110,7 @@
 		// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md#proposed-backoff-algorithm
 		connectDeadline := time.Now().Add(dialDuration)
 
-		ac.updateConnectivityState(connectivity.Connecting, nil)
+		ac.updateConnectivityState(connectivity.Connecting)
 		ac.transport = nil
 		ac.mu.Unlock()
 
@@ -1116,7 +1123,7 @@
 				ac.mu.Unlock()
 				return
 			}
-			ac.updateConnectivityState(connectivity.TransientFailure, err)
+			ac.updateConnectivityState(connectivity.TransientFailure)
 
 			// Backoff.
 			b := ac.resetBackoff
@@ -1172,7 +1179,6 @@
 // first successful one. It returns the transport, the address and a Event in
 // the successful case. The Event fires when the returned transport disconnects.
 func (ac *addrConn) tryAllAddrs(addrs []resolver.Address, connectDeadline time.Time) (transport.ClientTransport, resolver.Address, *grpcsync.Event, error) {
-	var firstConnErr error
 	for _, addr := range addrs {
 		ac.mu.Lock()
 		if ac.state == connectivity.Shutdown {
@@ -1190,20 +1196,22 @@
 		}
 		ac.mu.Unlock()
 
-		channelz.Infof(ac.channelzID, "Subchannel picks a new address %q to connect", addr.Addr)
+		if channelz.IsOn() {
+			channelz.AddTraceEvent(ac.channelzID, &channelz.TraceEventDesc{
+				Desc:     fmt.Sprintf("Subchannel picks a new address %q to connect", addr.Addr),
+				Severity: channelz.CtINFO,
+			})
+		}
 
 		newTr, reconnect, err := ac.createTransport(addr, copts, connectDeadline)
 		if err == nil {
 			return newTr, addr, reconnect, nil
 		}
-		if firstConnErr == nil {
-			firstConnErr = err
-		}
 		ac.cc.blockingpicker.updateConnectionError(err)
 	}
 
 	// Couldn't connect to any address.
-	return nil, resolver.Address{}, nil, firstConnErr
+	return nil, resolver.Address{}, nil, fmt.Errorf("couldn't connect to any address")
 }
 
 // createTransport creates a connection to addr. It returns the transport and a
@@ -1236,7 +1244,7 @@
 				// state to Connecting.
 				//
 				// TODO: this should be Idle when grpc-go properly supports it.
-				ac.updateConnectivityState(connectivity.Connecting, nil)
+				ac.updateConnectivityState(connectivity.Connecting)
 			}
 		})
 		ac.mu.Unlock()
@@ -1251,7 +1259,7 @@
 				// state to Connecting.
 				//
 				// TODO: this should be Idle when grpc-go properly supports it.
-				ac.updateConnectivityState(connectivity.Connecting, nil)
+				ac.updateConnectivityState(connectivity.Connecting)
 			}
 		})
 		ac.mu.Unlock()
@@ -1272,15 +1280,15 @@
 	newTr, err := transport.NewClientTransport(connectCtx, ac.cc.ctx, target, copts, onPrefaceReceipt, onGoAway, onClose)
 	if err != nil {
 		// newTr is either nil, or closed.
-		channelz.Warningf(ac.channelzID, "grpc: addrConn.createTransport failed to connect to %v. Err: %v. Reconnecting...", addr, err)
+		grpclog.Warningf("grpc: addrConn.createTransport failed to connect to %v. Err :%v. Reconnecting...", addr, err)
 		return nil, nil, err
 	}
 
 	select {
-	case <-time.After(time.Until(connectDeadline)):
+	case <-time.After(connectDeadline.Sub(time.Now())):
 		// We didn't get the preface in time.
 		newTr.Close()
-		channelz.Warningf(ac.channelzID, "grpc: addrConn.createTransport failed to connect to %v: didn't receive server preface in time. Reconnecting...", addr)
+		grpclog.Warningf("grpc: addrConn.createTransport failed to connect to %v: didn't receive server preface in time. Reconnecting...", addr)
 		return nil, nil, errors.New("timed out waiting for server handshake")
 	case <-prefaceReceived:
 		// We got the preface - huzzah! things are good.
@@ -1308,7 +1316,7 @@
 	var healthcheckManagingState bool
 	defer func() {
 		if !healthcheckManagingState {
-			ac.updateConnectivityState(connectivity.Ready, nil)
+			ac.updateConnectivityState(connectivity.Ready)
 		}
 	}()
 
@@ -1327,7 +1335,7 @@
 		// The health package is not imported to set health check function.
 		//
 		// TODO: add a link to the health check doc in the error message.
-		channelz.Error(ac.channelzID, "Health check is requested but health check function is not set.")
+		grpclog.Error("Health check is requested but health check function is not set.")
 		return
 	}
 
@@ -1344,22 +1352,28 @@
 		ac.mu.Unlock()
 		return newNonRetryClientStream(ctx, &StreamDesc{ServerStreams: true}, method, currentTr, ac)
 	}
-	setConnectivityState := func(s connectivity.State, lastErr error) {
+	setConnectivityState := func(s connectivity.State) {
 		ac.mu.Lock()
 		defer ac.mu.Unlock()
 		if ac.transport != currentTr {
 			return
 		}
-		ac.updateConnectivityState(s, lastErr)
+		ac.updateConnectivityState(s)
 	}
 	// Start the health checking stream.
 	go func() {
 		err := ac.cc.dopts.healthCheckFunc(ctx, newStream, setConnectivityState, healthCheckConfig.ServiceName)
 		if err != nil {
 			if status.Code(err) == codes.Unimplemented {
-				channelz.Error(ac.channelzID, "Subchannel health check is unimplemented at server side, thus health check is disabled")
+				if channelz.IsOn() {
+					channelz.AddTraceEvent(ac.channelzID, &channelz.TraceEventDesc{
+						Desc:     "Subchannel health check is unimplemented at server side, thus health check is disabled",
+						Severity: channelz.CtError,
+					})
+				}
+				grpclog.Error("Subchannel health check is unimplemented at server side, thus health check is disabled")
 			} else {
-				channelz.Errorf(ac.channelzID, "HealthCheckFunc exits with unexpected error %v", err)
+				grpclog.Errorf("HealthCheckFunc exits with unexpected error %v", err)
 			}
 		}
 	}()
@@ -1410,7 +1424,7 @@
 	ac.transport = nil
 	// We have to set the state to Shutdown before anything else to prevent races
 	// between setting the state and logic that waits on context cancellation / etc.
-	ac.updateConnectivityState(connectivity.Shutdown, nil)
+	ac.updateConnectivityState(connectivity.Shutdown)
 	ac.cancel()
 	ac.curAddr = resolver.Address{}
 	if err == errConnDrain && curTr != nil {
@@ -1424,7 +1438,7 @@
 		ac.mu.Lock()
 	}
 	if channelz.IsOn() {
-		channelz.AddTraceEvent(ac.channelzID, 0, &channelz.TraceEventDesc{
+		channelz.AddTraceEvent(ac.channelzID, &channelz.TraceEventDesc{
 			Desc:     "Subchannel Deleted",
 			Severity: channelz.CtINFO,
 			Parent: &channelz.TraceEventDesc{
@@ -1523,12 +1537,3 @@
 // Deprecated: This error is never returned by grpc and should not be
 // referenced by users.
 var ErrClientConnTimeout = errors.New("grpc: timed out when dialing")
-
-func (cc *ClientConn) getResolver(scheme string) resolver.Builder {
-	for _, rb := range cc.dopts.resolvers {
-		if scheme == rb.Scheme() {
-			return rb
-		}
-	}
-	return resolver.Get(scheme)
-}
diff --git a/vendor/google.golang.org/grpc/credentials/credentials.go b/vendor/google.golang.org/grpc/credentials/credentials.go
index e438fda..c690161 100644
--- a/vendor/google.golang.org/grpc/credentials/credentials.go
+++ b/vendor/google.golang.org/grpc/credentials/credentials.go
@@ -24,12 +24,17 @@
 
 import (
 	"context"
+	"crypto/tls"
+	"crypto/x509"
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"net"
 
 	"github.com/golang/protobuf/proto"
-	"google.golang.org/grpc/internal"
+
+	"google.golang.org/grpc/credentials/internal"
+	ginternal "google.golang.org/grpc/internal"
 )
 
 // PerRPCCredentials defines the common interface for the credentials which need to
@@ -51,48 +56,6 @@
 	RequireTransportSecurity() bool
 }
 
-// SecurityLevel defines the protection level on an established connection.
-//
-// This API is experimental.
-type SecurityLevel int
-
-const (
-	// NoSecurity indicates a connection is insecure.
-	// The zero SecurityLevel value is invalid for backward compatibility.
-	NoSecurity SecurityLevel = iota + 1
-	// IntegrityOnly indicates a connection only provides integrity protection.
-	IntegrityOnly
-	// PrivacyAndIntegrity indicates a connection provides both privacy and integrity protection.
-	PrivacyAndIntegrity
-)
-
-// String returns SecurityLevel in a string format.
-func (s SecurityLevel) String() string {
-	switch s {
-	case NoSecurity:
-		return "NoSecurity"
-	case IntegrityOnly:
-		return "IntegrityOnly"
-	case PrivacyAndIntegrity:
-		return "PrivacyAndIntegrity"
-	}
-	return fmt.Sprintf("invalid SecurityLevel: %v", int(s))
-}
-
-// CommonAuthInfo contains authenticated information common to AuthInfo implementations.
-// It should be embedded in a struct implementing AuthInfo to provide additional information
-// about the credentials.
-//
-// This API is experimental.
-type CommonAuthInfo struct {
-	SecurityLevel SecurityLevel
-}
-
-// GetCommonAuthInfo returns the pointer to CommonAuthInfo struct.
-func (c *CommonAuthInfo) GetCommonAuthInfo() *CommonAuthInfo {
-	return c
-}
-
 // ProtocolInfo provides information regarding the gRPC wire protocol version,
 // security protocol, security protocol version in use, server name, etc.
 type ProtocolInfo struct {
@@ -100,19 +63,13 @@
 	ProtocolVersion string
 	// SecurityProtocol is the security protocol in use.
 	SecurityProtocol string
-	// SecurityVersion is the security protocol version.  It is a static version string from the
-	// credentials, not a value that reflects per-connection protocol negotiation.  To retrieve
-	// details about the credentials used for a connection, use the Peer's AuthInfo field instead.
-	//
-	// Deprecated: please use Peer.AuthInfo.
+	// SecurityVersion is the security protocol version.
 	SecurityVersion string
 	// ServerName is the user-configured server name.
 	ServerName string
 }
 
 // AuthInfo defines the common interface for the auth information the users are interested in.
-// A struct that implements AuthInfo should embed CommonAuthInfo by including additional
-// information about the credentials in it.
 type AuthInfo interface {
 	AuthType() string
 }
@@ -127,8 +84,7 @@
 	// ClientHandshake does the authentication handshake specified by the corresponding
 	// authentication protocol on rawConn for clients. It returns the authenticated
 	// connection and the corresponding auth information about the connection.
-	// The auth information should embed CommonAuthInfo to return additional information about
-	// the credentials. Implementations must use the provided context to implement timely cancellation.
+	// Implementations must use the provided context to implement timely cancellation.
 	// gRPC will try to reconnect if the error returned is a temporary error
 	// (io.EOF, context.DeadlineExceeded or err.Temporary() == true).
 	// If the returned error is a wrapper error, implementations should make sure that
@@ -138,8 +94,7 @@
 	ClientHandshake(context.Context, string, net.Conn) (net.Conn, AuthInfo, error)
 	// ServerHandshake does the authentication handshake for servers. It returns
 	// the authenticated connection and the corresponding auth information about
-	// the connection. The auth information should embed CommonAuthInfo to return additional information
-	// about the credentials.
+	// the connection.
 	//
 	// If the returned net.Conn is closed, it MUST close the net.Conn provided.
 	ServerHandshake(net.Conn) (net.Conn, AuthInfo, error)
@@ -172,14 +127,223 @@
 	NewWithMode(mode string) (Bundle, error)
 }
 
+// TLSInfo contains the auth information for a TLS authenticated connection.
+// It implements the AuthInfo interface.
+type TLSInfo struct {
+	State tls.ConnectionState
+}
+
+// AuthType returns the type of TLSInfo as a string.
+func (t TLSInfo) AuthType() string {
+	return "tls"
+}
+
+// GetSecurityValue returns security info requested by channelz.
+func (t TLSInfo) GetSecurityValue() ChannelzSecurityValue {
+	v := &TLSChannelzSecurityValue{
+		StandardName: cipherSuiteLookup[t.State.CipherSuite],
+	}
+	// Currently there's no way to get LocalCertificate info from tls package.
+	if len(t.State.PeerCertificates) > 0 {
+		v.RemoteCertificate = t.State.PeerCertificates[0].Raw
+	}
+	return v
+}
+
+// tlsCreds is the credentials required for authenticating a connection using TLS.
+type tlsCreds struct {
+	// TLS configuration
+	config *tls.Config
+}
+
+func (c tlsCreds) Info() ProtocolInfo {
+	return ProtocolInfo{
+		SecurityProtocol: "tls",
+		SecurityVersion:  "1.2",
+		ServerName:       c.config.ServerName,
+	}
+}
+
+func (c *tlsCreds) ClientHandshake(ctx context.Context, authority string, rawConn net.Conn) (_ net.Conn, _ AuthInfo, err error) {
+	// use local cfg to avoid clobbering ServerName if using multiple endpoints
+	cfg := cloneTLSConfig(c.config)
+	if cfg.ServerName == "" {
+		serverName, _, err := net.SplitHostPort(authority)
+		if err != nil {
+			// If the authority had no host port or if the authority cannot be parsed, use it as-is.
+			serverName = authority
+		}
+		cfg.ServerName = serverName
+	}
+	conn := tls.Client(rawConn, cfg)
+	errChannel := make(chan error, 1)
+	go func() {
+		errChannel <- conn.Handshake()
+	}()
+	select {
+	case err := <-errChannel:
+		if err != nil {
+			return nil, nil, err
+		}
+	case <-ctx.Done():
+		return nil, nil, ctx.Err()
+	}
+	return internal.WrapSyscallConn(rawConn, conn), TLSInfo{conn.ConnectionState()}, nil
+}
+
+func (c *tlsCreds) ServerHandshake(rawConn net.Conn) (net.Conn, AuthInfo, error) {
+	conn := tls.Server(rawConn, c.config)
+	if err := conn.Handshake(); err != nil {
+		return nil, nil, err
+	}
+	return internal.WrapSyscallConn(rawConn, conn), TLSInfo{conn.ConnectionState()}, nil
+}
+
+func (c *tlsCreds) Clone() TransportCredentials {
+	return NewTLS(c.config)
+}
+
+func (c *tlsCreds) OverrideServerName(serverNameOverride string) error {
+	c.config.ServerName = serverNameOverride
+	return nil
+}
+
+const alpnProtoStrH2 = "h2"
+
+func appendH2ToNextProtos(ps []string) []string {
+	for _, p := range ps {
+		if p == alpnProtoStrH2 {
+			return ps
+		}
+	}
+	ret := make([]string, 0, len(ps)+1)
+	ret = append(ret, ps...)
+	return append(ret, alpnProtoStrH2)
+}
+
+// NewTLS uses c to construct a TransportCredentials based on TLS.
+func NewTLS(c *tls.Config) TransportCredentials {
+	tc := &tlsCreds{cloneTLSConfig(c)}
+	tc.config.NextProtos = appendH2ToNextProtos(tc.config.NextProtos)
+	return tc
+}
+
+// NewClientTLSFromCert constructs TLS credentials from the input certificate for client.
+// serverNameOverride is for testing only. If set to a non empty string,
+// it will override the virtual host name of authority (e.g. :authority header field) in requests.
+func NewClientTLSFromCert(cp *x509.CertPool, serverNameOverride string) TransportCredentials {
+	return NewTLS(&tls.Config{ServerName: serverNameOverride, RootCAs: cp})
+}
+
+// NewClientTLSFromFile constructs TLS credentials from the input certificate file for client.
+// serverNameOverride is for testing only. If set to a non empty string,
+// it will override the virtual host name of authority (e.g. :authority header field) in requests.
+func NewClientTLSFromFile(certFile, serverNameOverride string) (TransportCredentials, error) {
+	b, err := ioutil.ReadFile(certFile)
+	if err != nil {
+		return nil, err
+	}
+	cp := x509.NewCertPool()
+	if !cp.AppendCertsFromPEM(b) {
+		return nil, fmt.Errorf("credentials: failed to append certificates")
+	}
+	return NewTLS(&tls.Config{ServerName: serverNameOverride, RootCAs: cp}), nil
+}
+
+// NewServerTLSFromCert constructs TLS credentials from the input certificate for server.
+func NewServerTLSFromCert(cert *tls.Certificate) TransportCredentials {
+	return NewTLS(&tls.Config{Certificates: []tls.Certificate{*cert}})
+}
+
+// NewServerTLSFromFile constructs TLS credentials from the input certificate file and key
+// file for server.
+func NewServerTLSFromFile(certFile, keyFile string) (TransportCredentials, error) {
+	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
+	if err != nil {
+		return nil, err
+	}
+	return NewTLS(&tls.Config{Certificates: []tls.Certificate{cert}}), nil
+}
+
+// ChannelzSecurityInfo defines the interface that security protocols should implement
+// in order to provide security info to channelz.
+type ChannelzSecurityInfo interface {
+	GetSecurityValue() ChannelzSecurityValue
+}
+
+// ChannelzSecurityValue defines the interface that GetSecurityValue() return value
+// should satisfy. This interface should only be satisfied by *TLSChannelzSecurityValue
+// and *OtherChannelzSecurityValue.
+type ChannelzSecurityValue interface {
+	isChannelzSecurityValue()
+}
+
+// TLSChannelzSecurityValue defines the struct that TLS protocol should return
+// from GetSecurityValue(), containing security info like cipher and certificate used.
+type TLSChannelzSecurityValue struct {
+	ChannelzSecurityValue
+	StandardName      string
+	LocalCertificate  []byte
+	RemoteCertificate []byte
+}
+
+// OtherChannelzSecurityValue defines the struct that non-TLS protocol should return
+// from GetSecurityValue(), which contains protocol specific security info. Note
+// the Value field will be sent to users of channelz requesting channel info, and
+// thus sensitive info should better be avoided.
+type OtherChannelzSecurityValue struct {
+	ChannelzSecurityValue
+	Name  string
+	Value proto.Message
+}
+
+var cipherSuiteLookup = map[uint16]string{
+	tls.TLS_RSA_WITH_RC4_128_SHA:                "TLS_RSA_WITH_RC4_128_SHA",
+	tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA:           "TLS_RSA_WITH_3DES_EDE_CBC_SHA",
+	tls.TLS_RSA_WITH_AES_128_CBC_SHA:            "TLS_RSA_WITH_AES_128_CBC_SHA",
+	tls.TLS_RSA_WITH_AES_256_CBC_SHA:            "TLS_RSA_WITH_AES_256_CBC_SHA",
+	tls.TLS_RSA_WITH_AES_128_GCM_SHA256:         "TLS_RSA_WITH_AES_128_GCM_SHA256",
+	tls.TLS_RSA_WITH_AES_256_GCM_SHA384:         "TLS_RSA_WITH_AES_256_GCM_SHA384",
+	tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA:        "TLS_ECDHE_ECDSA_WITH_RC4_128_SHA",
+	tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA:    "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA",
+	tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA:    "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA",
+	tls.TLS_ECDHE_RSA_WITH_RC4_128_SHA:          "TLS_ECDHE_RSA_WITH_RC4_128_SHA",
+	tls.TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA:     "TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA",
+	tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA:      "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA",
+	tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:      "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA",
+	tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256:   "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
+	tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256: "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",
+	tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384:   "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384",
+	tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384: "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384",
+	tls.TLS_FALLBACK_SCSV:                       "TLS_FALLBACK_SCSV",
+	tls.TLS_RSA_WITH_AES_128_CBC_SHA256:         "TLS_RSA_WITH_AES_128_CBC_SHA256",
+	tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256: "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256",
+	tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256:   "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256",
+	tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305:    "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305",
+	tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305:  "TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305",
+}
+
+// cloneTLSConfig returns a shallow clone of the exported
+// fields of cfg, ignoring the unexported sync.Once, which
+// contains a mutex and must not be copied.
+//
+// If cfg is nil, a new zero tls.Config is returned.
+//
+// TODO: inline this function if possible.
+func cloneTLSConfig(cfg *tls.Config) *tls.Config {
+	if cfg == nil {
+		return &tls.Config{}
+	}
+
+	return cfg.Clone()
+}
+
 // RequestInfo contains request data attached to the context passed to GetRequestMetadata calls.
 //
 // This API is experimental.
 type RequestInfo struct {
 	// The method passed to Invoke or NewStream for this RPC. (For proto methods, this has the format "/some.Service/Method")
 	Method string
-	// AuthInfo contains the information from a security handshake (TransportCredentials.ClientHandshake, TransportCredentials.ServerHandshake)
-	AuthInfo AuthInfo
 }
 
 // requestInfoKey is a struct to be used as the key when attaching a RequestInfo to a context object.
@@ -193,63 +357,8 @@
 	return
 }
 
-// CheckSecurityLevel checks if a connection's security level is greater than or equal to the specified one.
-// It returns success if 1) the condition is satisified or 2) AuthInfo struct does not implement GetCommonAuthInfo() method
-// or 3) CommonAuthInfo.SecurityLevel has an invalid zero value. For 2) and 3), it is for the purpose of backward-compatibility.
-//
-// This API is experimental.
-func CheckSecurityLevel(ctx context.Context, level SecurityLevel) error {
-	type internalInfo interface {
-		GetCommonAuthInfo() *CommonAuthInfo
-	}
-	ri, _ := RequestInfoFromContext(ctx)
-	if ri.AuthInfo == nil {
-		return errors.New("unable to obtain SecurityLevel from context")
-	}
-	if ci, ok := ri.AuthInfo.(internalInfo); ok {
-		// CommonAuthInfo.SecurityLevel has an invalid value.
-		if ci.GetCommonAuthInfo().SecurityLevel == 0 {
-			return nil
-		}
-		if ci.GetCommonAuthInfo().SecurityLevel < level {
-			return fmt.Errorf("requires SecurityLevel %v; connection has %v", level, ci.GetCommonAuthInfo().SecurityLevel)
-		}
-	}
-	// The condition is satisfied or AuthInfo struct does not implement GetCommonAuthInfo() method.
-	return nil
-}
-
 func init() {
-	internal.NewRequestInfoContext = func(ctx context.Context, ri RequestInfo) context.Context {
+	ginternal.NewRequestInfoContext = func(ctx context.Context, ri RequestInfo) context.Context {
 		return context.WithValue(ctx, requestInfoKey{}, ri)
 	}
 }
-
-// ChannelzSecurityInfo defines the interface that security protocols should implement
-// in order to provide security info to channelz.
-//
-// This API is experimental.
-type ChannelzSecurityInfo interface {
-	GetSecurityValue() ChannelzSecurityValue
-}
-
-// ChannelzSecurityValue defines the interface that GetSecurityValue() return value
-// should satisfy. This interface should only be satisfied by *TLSChannelzSecurityValue
-// and *OtherChannelzSecurityValue.
-//
-// This API is experimental.
-type ChannelzSecurityValue interface {
-	isChannelzSecurityValue()
-}
-
-// OtherChannelzSecurityValue defines the struct that non-TLS protocol should return
-// from GetSecurityValue(), which contains protocol specific security info. Note
-// the Value field will be sent to users of channelz requesting channel info, and
-// thus sensitive info should better be avoided.
-//
-// This API is experimental.
-type OtherChannelzSecurityValue struct {
-	ChannelzSecurityValue
-	Name  string
-	Value proto.Message
-}
diff --git a/vendor/google.golang.org/grpc/credentials/tls.go b/vendor/google.golang.org/grpc/credentials/tls.go
deleted file mode 100644
index 86e956b..0000000
--- a/vendor/google.golang.org/grpc/credentials/tls.go
+++ /dev/null
@@ -1,235 +0,0 @@
-/*
- *
- * Copyright 2014 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-package credentials
-
-import (
-	"context"
-	"crypto/tls"
-	"crypto/x509"
-	"fmt"
-	"io/ioutil"
-	"net"
-
-	"google.golang.org/grpc/credentials/internal"
-)
-
-// TLSInfo contains the auth information for a TLS authenticated connection.
-// It implements the AuthInfo interface.
-type TLSInfo struct {
-	State tls.ConnectionState
-	CommonAuthInfo
-}
-
-// AuthType returns the type of TLSInfo as a string.
-func (t TLSInfo) AuthType() string {
-	return "tls"
-}
-
-// GetSecurityValue returns security info requested by channelz.
-func (t TLSInfo) GetSecurityValue() ChannelzSecurityValue {
-	v := &TLSChannelzSecurityValue{
-		StandardName: cipherSuiteLookup[t.State.CipherSuite],
-	}
-	// Currently there's no way to get LocalCertificate info from tls package.
-	if len(t.State.PeerCertificates) > 0 {
-		v.RemoteCertificate = t.State.PeerCertificates[0].Raw
-	}
-	return v
-}
-
-// tlsCreds is the credentials required for authenticating a connection using TLS.
-type tlsCreds struct {
-	// TLS configuration
-	config *tls.Config
-}
-
-func (c tlsCreds) Info() ProtocolInfo {
-	return ProtocolInfo{
-		SecurityProtocol: "tls",
-		SecurityVersion:  "1.2",
-		ServerName:       c.config.ServerName,
-	}
-}
-
-func (c *tlsCreds) ClientHandshake(ctx context.Context, authority string, rawConn net.Conn) (_ net.Conn, _ AuthInfo, err error) {
-	// use local cfg to avoid clobbering ServerName if using multiple endpoints
-	cfg := cloneTLSConfig(c.config)
-	if cfg.ServerName == "" {
-		serverName, _, err := net.SplitHostPort(authority)
-		if err != nil {
-			// If the authority had no host port or if the authority cannot be parsed, use it as-is.
-			serverName = authority
-		}
-		cfg.ServerName = serverName
-	}
-	conn := tls.Client(rawConn, cfg)
-	errChannel := make(chan error, 1)
-	go func() {
-		errChannel <- conn.Handshake()
-		close(errChannel)
-	}()
-	select {
-	case err := <-errChannel:
-		if err != nil {
-			conn.Close()
-			return nil, nil, err
-		}
-	case <-ctx.Done():
-		conn.Close()
-		return nil, nil, ctx.Err()
-	}
-	return internal.WrapSyscallConn(rawConn, conn), TLSInfo{conn.ConnectionState(), CommonAuthInfo{PrivacyAndIntegrity}}, nil
-}
-
-func (c *tlsCreds) ServerHandshake(rawConn net.Conn) (net.Conn, AuthInfo, error) {
-	conn := tls.Server(rawConn, c.config)
-	if err := conn.Handshake(); err != nil {
-		conn.Close()
-		return nil, nil, err
-	}
-	return internal.WrapSyscallConn(rawConn, conn), TLSInfo{conn.ConnectionState(), CommonAuthInfo{PrivacyAndIntegrity}}, nil
-}
-
-func (c *tlsCreds) Clone() TransportCredentials {
-	return NewTLS(c.config)
-}
-
-func (c *tlsCreds) OverrideServerName(serverNameOverride string) error {
-	c.config.ServerName = serverNameOverride
-	return nil
-}
-
-const alpnProtoStrH2 = "h2"
-
-func appendH2ToNextProtos(ps []string) []string {
-	for _, p := range ps {
-		if p == alpnProtoStrH2 {
-			return ps
-		}
-	}
-	ret := make([]string, 0, len(ps)+1)
-	ret = append(ret, ps...)
-	return append(ret, alpnProtoStrH2)
-}
-
-// NewTLS uses c to construct a TransportCredentials based on TLS.
-func NewTLS(c *tls.Config) TransportCredentials {
-	tc := &tlsCreds{cloneTLSConfig(c)}
-	tc.config.NextProtos = appendH2ToNextProtos(tc.config.NextProtos)
-	return tc
-}
-
-// NewClientTLSFromCert constructs TLS credentials from the provided root
-// certificate authority certificate(s) to validate server connections. If
-// certificates to establish the identity of the client need to be included in
-// the credentials (eg: for mTLS), use NewTLS instead, where a complete
-// tls.Config can be specified.
-// serverNameOverride is for testing only. If set to a non empty string,
-// it will override the virtual host name of authority (e.g. :authority header
-// field) in requests.
-func NewClientTLSFromCert(cp *x509.CertPool, serverNameOverride string) TransportCredentials {
-	return NewTLS(&tls.Config{ServerName: serverNameOverride, RootCAs: cp})
-}
-
-// NewClientTLSFromFile constructs TLS credentials from the provided root
-// certificate authority certificate file(s) to validate server connections. If
-// certificates to establish the identity of the client need to be included in
-// the credentials (eg: for mTLS), use NewTLS instead, where a complete
-// tls.Config can be specified.
-// serverNameOverride is for testing only. If set to a non empty string,
-// it will override the virtual host name of authority (e.g. :authority header
-// field) in requests.
-func NewClientTLSFromFile(certFile, serverNameOverride string) (TransportCredentials, error) {
-	b, err := ioutil.ReadFile(certFile)
-	if err != nil {
-		return nil, err
-	}
-	cp := x509.NewCertPool()
-	if !cp.AppendCertsFromPEM(b) {
-		return nil, fmt.Errorf("credentials: failed to append certificates")
-	}
-	return NewTLS(&tls.Config{ServerName: serverNameOverride, RootCAs: cp}), nil
-}
-
-// NewServerTLSFromCert constructs TLS credentials from the input certificate for server.
-func NewServerTLSFromCert(cert *tls.Certificate) TransportCredentials {
-	return NewTLS(&tls.Config{Certificates: []tls.Certificate{*cert}})
-}
-
-// NewServerTLSFromFile constructs TLS credentials from the input certificate file and key
-// file for server.
-func NewServerTLSFromFile(certFile, keyFile string) (TransportCredentials, error) {
-	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
-	if err != nil {
-		return nil, err
-	}
-	return NewTLS(&tls.Config{Certificates: []tls.Certificate{cert}}), nil
-}
-
-// TLSChannelzSecurityValue defines the struct that TLS protocol should return
-// from GetSecurityValue(), containing security info like cipher and certificate used.
-//
-// This API is EXPERIMENTAL.
-type TLSChannelzSecurityValue struct {
-	ChannelzSecurityValue
-	StandardName      string
-	LocalCertificate  []byte
-	RemoteCertificate []byte
-}
-
-var cipherSuiteLookup = map[uint16]string{
-	tls.TLS_RSA_WITH_RC4_128_SHA:                "TLS_RSA_WITH_RC4_128_SHA",
-	tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA:           "TLS_RSA_WITH_3DES_EDE_CBC_SHA",
-	tls.TLS_RSA_WITH_AES_128_CBC_SHA:            "TLS_RSA_WITH_AES_128_CBC_SHA",
-	tls.TLS_RSA_WITH_AES_256_CBC_SHA:            "TLS_RSA_WITH_AES_256_CBC_SHA",
-	tls.TLS_RSA_WITH_AES_128_GCM_SHA256:         "TLS_RSA_WITH_AES_128_GCM_SHA256",
-	tls.TLS_RSA_WITH_AES_256_GCM_SHA384:         "TLS_RSA_WITH_AES_256_GCM_SHA384",
-	tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA:        "TLS_ECDHE_ECDSA_WITH_RC4_128_SHA",
-	tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA:    "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA",
-	tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA:    "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA",
-	tls.TLS_ECDHE_RSA_WITH_RC4_128_SHA:          "TLS_ECDHE_RSA_WITH_RC4_128_SHA",
-	tls.TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA:     "TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA",
-	tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA:      "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA",
-	tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:      "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA",
-	tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256:   "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
-	tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256: "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",
-	tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384:   "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384",
-	tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384: "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384",
-	tls.TLS_FALLBACK_SCSV:                       "TLS_FALLBACK_SCSV",
-	tls.TLS_RSA_WITH_AES_128_CBC_SHA256:         "TLS_RSA_WITH_AES_128_CBC_SHA256",
-	tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256: "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256",
-	tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256:   "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256",
-	tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305:    "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305",
-	tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305:  "TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305",
-}
-
-// cloneTLSConfig returns a shallow clone of the exported
-// fields of cfg, ignoring the unexported sync.Once, which
-// contains a mutex and must not be copied.
-//
-// If cfg is nil, a new zero tls.Config is returned.
-//
-// TODO: inline this function if possible.
-func cloneTLSConfig(cfg *tls.Config) *tls.Config {
-	if cfg == nil {
-		return &tls.Config{}
-	}
-
-	return cfg.Clone()
-}
diff --git a/vendor/google.golang.org/grpc/credentials/go12.go b/vendor/google.golang.org/grpc/credentials/tls13.go
similarity index 100%
rename from vendor/google.golang.org/grpc/credentials/go12.go
rename to vendor/google.golang.org/grpc/credentials/tls13.go
diff --git a/vendor/google.golang.org/grpc/dialoptions.go b/vendor/google.golang.org/grpc/dialoptions.go
index 35bde10..9f872df 100644
--- a/vendor/google.golang.org/grpc/dialoptions.go
+++ b/vendor/google.golang.org/grpc/dialoptions.go
@@ -58,7 +58,9 @@
 	callOptions []CallOption
 	// This is used by v1 balancer dial option WithBalancer to support v1
 	// balancer, and also by WithBalancerName dial option.
-	balancerBuilder             balancer.Builder
+	balancerBuilder balancer.Builder
+	// This is to support grpclb.
+	resolverBuilder             resolver.Builder
 	channelzParentID            int64
 	disableServiceConfig        bool
 	disableRetry                bool
@@ -71,8 +73,6 @@
 	// resolver.ResolveNow(). The user will have no need to configure this, but
 	// we need to be able to configure this in tests.
 	resolveNowBackoff func(int) time.Duration
-	resolvers         []resolver.Builder
-	withProxy         bool
 }
 
 // DialOption configures how we set up the connection.
@@ -231,6 +231,13 @@
 	})
 }
 
+// withResolverBuilder is only for grpclb.
+func withResolverBuilder(b resolver.Builder) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.resolverBuilder = b
+	})
+}
+
 // WithServiceConfig returns a DialOption which has a channel to read the
 // service configuration.
 //
@@ -308,16 +315,6 @@
 	})
 }
 
-// WithNoProxy returns a DialOption which disables the use of proxies for this
-// ClientConn. This is ignored if WithDialer or WithContextDialer are used.
-//
-// This API is EXPERIMENTAL.
-func WithNoProxy() DialOption {
-	return newFuncDialOption(func(o *dialOptions) {
-		o.withProxy = false
-	})
-}
-
 // WithTransportCredentials returns a DialOption which configures a connection
 // level security credentials (e.g., TLS/SSL). This should not be used together
 // with WithCredentialsBundle.
@@ -349,8 +346,8 @@
 // WithTimeout returns a DialOption that configures a timeout for dialing a
 // ClientConn initially. This is valid if and only if WithBlock() is present.
 //
-// Deprecated: use DialContext instead of Dial and context.WithTimeout
-// instead.  Will be supported throughout 1.x.
+// Deprecated: use DialContext and context.WithTimeout instead.  Will be
+// supported throughout 1.x.
 func WithTimeout(d time.Duration) DialOption {
 	return newFuncDialOption(func(o *dialOptions) {
 		o.timeout = d
@@ -368,6 +365,7 @@
 }
 
 func init() {
+	internal.WithResolverBuilder = withResolverBuilder
 	internal.WithHealthCheckFunc = withHealthCheckFunc
 }
 
@@ -481,8 +479,6 @@
 // WithChannelzParentID returns a DialOption that specifies the channelz ID of
 // current ClientConn's parent. This function is used in nested channel creation
 // (e.g. grpclb dial).
-//
-// This API is EXPERIMENTAL.
 func WithChannelzParentID(id int64) DialOption {
 	return newFuncDialOption(func(o *dialOptions) {
 		o.channelzParentID = id
@@ -568,7 +564,6 @@
 			ReadBufferSize:  defaultReadBufSize,
 		},
 		resolveNowBackoff: internalbackoff.DefaultExponential.Backoff,
-		withProxy:         true,
 	}
 }
 
@@ -592,15 +587,3 @@
 		o.resolveNowBackoff = f
 	})
 }
-
-// WithResolvers allows a list of resolver implementations to be registered
-// locally with the ClientConn without needing to be globally registered via
-// resolver.Register.  They will be matched against the scheme used for the
-// current Dial only, and will take precedence over the global registry.
-//
-// This API is EXPERIMENTAL.
-func WithResolvers(rs ...resolver.Builder) DialOption {
-	return newFuncDialOption(func(o *dialOptions) {
-		o.resolvers = append(o.resolvers, rs...)
-	})
-}
diff --git a/vendor/google.golang.org/grpc/go.mod b/vendor/google.golang.org/grpc/go.mod
index ecef1ab..dc56aa7 100644
--- a/vendor/google.golang.org/grpc/go.mod
+++ b/vendor/google.golang.org/grpc/go.mod
@@ -3,11 +3,11 @@
 go 1.11
 
 require (
-	github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f
-	github.com/envoyproxy/go-control-plane v0.9.4
+	github.com/envoyproxy/go-control-plane v0.9.0
+	github.com/envoyproxy/protoc-gen-validate v0.1.0
 	github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b
 	github.com/golang/mock v1.1.1
-	github.com/golang/protobuf v1.3.3
+	github.com/golang/protobuf v1.3.2
 	github.com/google/go-cmp v0.2.0
 	golang.org/x/net v0.0.0-20190311183353-d8887717615a
 	golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be
diff --git a/vendor/google.golang.org/grpc/go.sum b/vendor/google.golang.org/grpc/go.sum
index 0bf9f07..f6a4784 100644
--- a/vendor/google.golang.org/grpc/go.sum
+++ b/vendor/google.golang.org/grpc/go.sum
@@ -1,15 +1,10 @@
 cloud.google.com/go v0.26.0 h1:e0WKqKTd5BnrG8aKH3J3h+QvEIQtSUcf2n5UZ5ZgLtQ=
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
-github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
-github.com/client9/misspell v0.3.4 h1:ta993UF76GwbvJcIo3Y68y/M3WxlpEHPWIGDkJYwzJI=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
-github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f h1:WBZRG4aNOuI15bLRrCgN8fCq8E5Xuty6jGbmSNEvSsU=
-github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
+github.com/envoyproxy/go-control-plane v0.9.0 h1:67WMNTvGrl7V1dWdKCeTwxDr7nio9clKoTlLhwIPnT4=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
-github.com/envoyproxy/go-control-plane v0.9.4 h1:rEvIZUSZ3fx39WIi3JkQqQBitGwpELBIYWeBVh6wn+E=
-github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
 github.com/envoyproxy/protoc-gen-validate v0.1.0 h1:EQciDnbrYxy13PgWoY8AqoxGiPrpgBZ1R8UNe3ddc+A=
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b h1:VKtxabqXZkF25pY9ekfRL6a582T4P37/31XEstQ5p58=
@@ -19,8 +14,6 @@
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.2 h1:6nsPYzhq5kReh6QImI3k5qWzO4PEbvbIW2cwSfR/6xs=
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
-github.com/golang/protobuf v1.3.3 h1:gyjaxf+svBWX08ZjK86iN9geUJF0H6gp2IRKX6Nf6/I=
-github.com/golang/protobuf v1.3.3/go.mod h1:vzj43D7+SQXF/4pzW/hwtAqwc6iTitCiVSaWz5lYuqw=
 github.com/google/go-cmp v0.2.0 h1:+dTQ8DZQJz0Mb/HjFlkptS1FeQ4cWSnN941F8aEG4SQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
@@ -28,7 +21,6 @@
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvxsM5YxQ5yQlVC4a0KAMCusXpPoU=
-golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3 h1:XQyxROzUlZH+WIQwySDgnISgOivlhjIEwaQaJEJrrN0=
 golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -48,7 +40,6 @@
 golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190226205152-f727befe758c/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=
 golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
-golang.org/x/tools v0.0.0-20190524140312-2c0ae7006135 h1:5Beo0mZN8dRzgrMMkDp0jc8YXQKx9DiJ2k1dkvGsn5A=
 golang.org/x/tools v0.0.0-20190524140312-2c0ae7006135/go.mod h1:RgjU9mgBXZiqYHBnxXauZ1Gv1EHHAz9KjViQ78xBX0Q=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
 google.golang.org/appengine v1.4.0 h1:/wp5JvzpHIxhs/dumFmF7BXTf3Z+dd4uXta4kVyO508=
@@ -58,7 +49,5 @@
 google.golang.org/genproto v0.0.0-20190819201941-24fa4b261c55/go.mod h1:DMBHOl98Agz4BDEuKkezgsaosCRResVns1a3J2ZsMNc=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
 google.golang.org/grpc v1.23.0/go.mod h1:Y5yQAOtifL1yxbo5wqy6BxZv8vAUGQwXBOALyacEbxg=
-google.golang.org/grpc v1.25.1/go.mod h1:c3i+UQWmh7LiEpx4sFZnkU36qjEYZ0imhYfXVyQciAY=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
-honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc h1:/hemPrYIhOhy8zYrNj+069zDB68us2sMGsfkFJO0iZs=
 honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
diff --git a/vendor/google.golang.org/grpc/grpclog/grpclog.go b/vendor/google.golang.org/grpc/grpclog/grpclog.go
index c8bb2be..874ea6d 100644
--- a/vendor/google.golang.org/grpc/grpclog/grpclog.go
+++ b/vendor/google.golang.org/grpc/grpclog/grpclog.go
@@ -26,70 +26,64 @@
 // verbosity level can be set by GRPC_GO_LOG_VERBOSITY_LEVEL.
 package grpclog // import "google.golang.org/grpc/grpclog"
 
-import (
-	"os"
+import "os"
 
-	"google.golang.org/grpc/internal/grpclog"
-)
-
-func init() {
-	SetLoggerV2(newLoggerV2())
-}
+var logger = newLoggerV2()
 
 // V reports whether verbosity level l is at least the requested verbose level.
 func V(l int) bool {
-	return grpclog.Logger.V(l)
+	return logger.V(l)
 }
 
 // Info logs to the INFO log.
 func Info(args ...interface{}) {
-	grpclog.Logger.Info(args...)
+	logger.Info(args...)
 }
 
 // Infof logs to the INFO log. Arguments are handled in the manner of fmt.Printf.
 func Infof(format string, args ...interface{}) {
-	grpclog.Logger.Infof(format, args...)
+	logger.Infof(format, args...)
 }
 
 // Infoln logs to the INFO log. Arguments are handled in the manner of fmt.Println.
 func Infoln(args ...interface{}) {
-	grpclog.Logger.Infoln(args...)
+	logger.Infoln(args...)
 }
 
 // Warning logs to the WARNING log.
 func Warning(args ...interface{}) {
-	grpclog.Logger.Warning(args...)
+	logger.Warning(args...)
 }
 
 // Warningf logs to the WARNING log. Arguments are handled in the manner of fmt.Printf.
 func Warningf(format string, args ...interface{}) {
-	grpclog.Logger.Warningf(format, args...)
+	logger.Warningf(format, args...)
 }
 
 // Warningln logs to the WARNING log. Arguments are handled in the manner of fmt.Println.
 func Warningln(args ...interface{}) {
-	grpclog.Logger.Warningln(args...)
+	logger.Warningln(args...)
 }
 
 // Error logs to the ERROR log.
 func Error(args ...interface{}) {
-	grpclog.Logger.Error(args...)
+	logger.Error(args...)
 }
 
 // Errorf logs to the ERROR log. Arguments are handled in the manner of fmt.Printf.
 func Errorf(format string, args ...interface{}) {
-	grpclog.Logger.Errorf(format, args...)
+	logger.Errorf(format, args...)
 }
 
 // Errorln logs to the ERROR log. Arguments are handled in the manner of fmt.Println.
 func Errorln(args ...interface{}) {
-	grpclog.Logger.Errorln(args...)
+	logger.Errorln(args...)
 }
 
 // Fatal logs to the FATAL log. Arguments are handled in the manner of fmt.Print.
 // It calls os.Exit() with exit code 1.
 func Fatal(args ...interface{}) {
-	grpclog.Logger.Fatal(args...)
+	logger.Fatal(args...)
 	// Make sure fatal logs will exit.
 	os.Exit(1)
 }
@@ -97,7 +91,7 @@
 // Fatalf logs to the FATAL log. Arguments are handled in the manner of fmt.Printf.
 // It calls os.Exit() with exit code 1.
 func Fatalf(format string, args ...interface{}) {
-	grpclog.Logger.Fatalf(format, args...)
+	logger.Fatalf(format, args...)
 	// Make sure fatal logs will exit.
 	os.Exit(1)
 }
@@ -105,7 +99,7 @@
 // Fatalln logs to the FATAL log. Arguments are handled in the manner of fmt.Println.
 // It calle os.Exit()) with exit code 1.
 func Fatalln(args ...interface{}) {
-	grpclog.Logger.Fatalln(args...)
+	logger.Fatalln(args...)
 	// Make sure fatal logs will exit.
 	os.Exit(1)
 }
@@ -114,19 +108,19 @@
 //
 // Deprecated: use Info.
 func Print(args ...interface{}) {
-	grpclog.Logger.Info(args...)
+	logger.Info(args...)
 }
 
 // Printf prints to the logger. Arguments are handled in the manner of fmt.Printf.
 //
 // Deprecated: use Infof.
 func Printf(format string, args ...interface{}) {
-	grpclog.Logger.Infof(format, args...)
+	logger.Infof(format, args...)
 }
 
 // Println prints to the logger. Arguments are handled in the manner of fmt.Println.
 //
 // Deprecated: use Infoln.
 func Println(args ...interface{}) {
-	grpclog.Logger.Infoln(args...)
+	logger.Infoln(args...)
 }
diff --git a/vendor/google.golang.org/grpc/grpclog/logger.go b/vendor/google.golang.org/grpc/grpclog/logger.go
index ef06a48..097494f 100644
--- a/vendor/google.golang.org/grpc/grpclog/logger.go
+++ b/vendor/google.golang.org/grpc/grpclog/logger.go
@@ -18,8 +18,6 @@
 
 package grpclog
 
-import "google.golang.org/grpc/internal/grpclog"
-
 // Logger mimics golang's standard Logger as an interface.
 //
 // Deprecated: use LoggerV2.
@@ -37,7 +35,7 @@
 //
 // Deprecated: use SetLoggerV2.
 func SetLogger(l Logger) {
-	grpclog.Logger = &loggerWrapper{Logger: l}
+	logger = &loggerWrapper{Logger: l}
 }
 
 // loggerWrapper wraps Logger into a LoggerV2.
diff --git a/vendor/google.golang.org/grpc/grpclog/loggerv2.go b/vendor/google.golang.org/grpc/grpclog/loggerv2.go
index 23612b7..d493257 100644
--- a/vendor/google.golang.org/grpc/grpclog/loggerv2.go
+++ b/vendor/google.golang.org/grpc/grpclog/loggerv2.go
@@ -24,8 +24,6 @@
 	"log"
 	"os"
 	"strconv"
-
-	"google.golang.org/grpc/internal/grpclog"
 )
 
 // LoggerV2 does underlying logging work for grpclog.
@@ -67,8 +65,7 @@
 // SetLoggerV2 sets logger that is used in grpc to a V2 logger.
 // Not mutex-protected, should be called before any gRPC functions.
 func SetLoggerV2(l LoggerV2) {
-	grpclog.Logger = l
-	grpclog.DepthLogger, _ = l.(grpclog.DepthLoggerV2)
+	logger = l
 }
 
 const (
@@ -196,19 +193,3 @@
 func (g *loggerT) V(l int) bool {
 	return l <= g.v
 }
-
-// DepthLoggerV2 logs at a specified call frame. If a LoggerV2 also implements
-// DepthLoggerV2, the below functions will be called with the appropriate stack
-// depth set for trivial functions the logger may ignore.
-//
-// This API is EXPERIMENTAL.
-type DepthLoggerV2 interface {
-	// InfoDepth logs to INFO log at the specified depth. Arguments are handled in the manner of fmt.Print.
-	InfoDepth(depth int, args ...interface{})
-	// WarningDepth logs to WARNING log at the specified depth. Arguments are handled in the manner of fmt.Print.
-	WarningDepth(depth int, args ...interface{})
-	// ErrorDetph logs to ERROR log at the specified depth. Arguments are handled in the manner of fmt.Print.
-	ErrorDepth(depth int, args ...interface{})
-	// FatalDepth logs to FATAL log at the specified depth. Arguments are handled in the manner of fmt.Print.
-	FatalDepth(depth int, args ...interface{})
-}
diff --git a/vendor/google.golang.org/grpc/internal/binarylog/binarylog.go b/vendor/google.golang.org/grpc/internal/binarylog/binarylog.go
index 8b10516..4062c02 100644
--- a/vendor/google.golang.org/grpc/internal/binarylog/binarylog.go
+++ b/vendor/google.golang.org/grpc/internal/binarylog/binarylog.go
@@ -98,7 +98,7 @@
 // New methodLogger with same service overrides the old one.
 func (l *logger) setServiceMethodLogger(service string, ml *methodLoggerConfig) error {
 	if _, ok := l.services[service]; ok {
-		return fmt.Errorf("conflicting service rules for service %v found", service)
+		return fmt.Errorf("conflicting rules for service %v found", service)
 	}
 	if l.services == nil {
 		l.services = make(map[string]*methodLoggerConfig)
@@ -112,10 +112,10 @@
 // New methodLogger with same method overrides the old one.
 func (l *logger) setMethodMethodLogger(method string, ml *methodLoggerConfig) error {
 	if _, ok := l.blacklist[method]; ok {
-		return fmt.Errorf("conflicting blacklist rules for method %v found", method)
+		return fmt.Errorf("conflicting rules for method %v found", method)
 	}
 	if _, ok := l.methods[method]; ok {
-		return fmt.Errorf("conflicting method rules for method %v found", method)
+		return fmt.Errorf("conflicting rules for method %v found", method)
 	}
 	if l.methods == nil {
 		l.methods = make(map[string]*methodLoggerConfig)
@@ -127,10 +127,10 @@
 // Set blacklist method for "-service/method".
 func (l *logger) setBlacklist(method string) error {
 	if _, ok := l.blacklist[method]; ok {
-		return fmt.Errorf("conflicting blacklist rules for method %v found", method)
+		return fmt.Errorf("conflicting rules for method %v found", method)
 	}
 	if _, ok := l.methods[method]; ok {
-		return fmt.Errorf("conflicting method rules for method %v found", method)
+		return fmt.Errorf("conflicting rules for method %v found", method)
 	}
 	if l.blacklist == nil {
 		l.blacklist = make(map[string]struct{})
diff --git a/vendor/google.golang.org/grpc/internal/buffer/unbounded.go b/vendor/google.golang.org/grpc/internal/buffer/unbounded.go
index 9f6a0c1..2cb3109 100644
--- a/vendor/google.golang.org/grpc/internal/buffer/unbounded.go
+++ b/vendor/google.golang.org/grpc/internal/buffer/unbounded.go
@@ -26,13 +26,6 @@
 //
 // All methods on this type are thread-safe and don't block on anything except
 // the underlying mutex used for synchronization.
-//
-// Unbounded supports values of any type to be stored in it by using a channel
-// of `interface{}`. This means that a call to Put() incurs an extra memory
-// allocation, and also that users need a type assertion while reading. For
-// performance critical code paths, using Unbounded is strongly discouraged and
-// defining a new type specific implementation of this buffer is preferred. See
-// internal/transport/transport.go for an example of this.
 type Unbounded struct {
 	c       chan interface{}
 	mu      sync.Mutex
diff --git a/vendor/google.golang.org/grpc/internal/channelz/funcs.go b/vendor/google.golang.org/grpc/internal/channelz/funcs.go
index e4252e5..f0744f9 100644
--- a/vendor/google.golang.org/grpc/internal/channelz/funcs.go
+++ b/vendor/google.golang.org/grpc/internal/channelz/funcs.go
@@ -30,7 +30,7 @@
 	"sync/atomic"
 	"time"
 
-	"google.golang.org/grpc/internal/grpclog"
+	"google.golang.org/grpc/grpclog"
 )
 
 const (
@@ -216,7 +216,7 @@
 // by pid). It returns the unique channelz tracking id assigned to this subchannel.
 func RegisterSubChannel(c Channel, pid int64, ref string) int64 {
 	if pid == 0 {
-		grpclog.ErrorDepth(0, "a SubChannel's parent id cannot be 0")
+		grpclog.Error("a SubChannel's parent id cannot be 0")
 		return 0
 	}
 	id := idGen.genID()
@@ -253,7 +253,7 @@
 // this listen socket.
 func RegisterListenSocket(s Socket, pid int64, ref string) int64 {
 	if pid == 0 {
-		grpclog.ErrorDepth(0, "a ListenSocket's parent id cannot be 0")
+		grpclog.Error("a ListenSocket's parent id cannot be 0")
 		return 0
 	}
 	id := idGen.genID()
@@ -268,7 +268,7 @@
 // this normal socket.
 func RegisterNormalSocket(s Socket, pid int64, ref string) int64 {
 	if pid == 0 {
-		grpclog.ErrorDepth(0, "a NormalSocket's parent id cannot be 0")
+		grpclog.Error("a NormalSocket's parent id cannot be 0")
 		return 0
 	}
 	id := idGen.genID()
@@ -294,19 +294,7 @@
 }
 
 // AddTraceEvent adds trace related to the entity with specified id, using the provided TraceEventDesc.
-func AddTraceEvent(id int64, depth int, desc *TraceEventDesc) {
-	for d := desc; d != nil; d = d.Parent {
-		switch d.Severity {
-		case CtUNKNOWN:
-			grpclog.InfoDepth(depth+1, d.Desc)
-		case CtINFO:
-			grpclog.InfoDepth(depth+1, d.Desc)
-		case CtWarning:
-			grpclog.WarningDepth(depth+1, d.Desc)
-		case CtError:
-			grpclog.ErrorDepth(depth+1, d.Desc)
-		}
-	}
+func AddTraceEvent(id int64, desc *TraceEventDesc) {
 	if getMaxTraceEntry() == 0 {
 		return
 	}
diff --git a/vendor/google.golang.org/grpc/internal/channelz/logging.go b/vendor/google.golang.org/grpc/internal/channelz/logging.go
deleted file mode 100644
index 59c7bed..0000000
--- a/vendor/google.golang.org/grpc/internal/channelz/logging.go
+++ /dev/null
@@ -1,100 +0,0 @@
-/*
- *
- * Copyright 2020 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-package channelz
-
-import (
-	"fmt"
-
-	"google.golang.org/grpc/internal/grpclog"
-)
-
-// Info logs through grpclog.Info and adds a trace event if channelz is on.
-func Info(id int64, args ...interface{}) {
-	if IsOn() {
-		AddTraceEvent(id, 1, &TraceEventDesc{
-			Desc:     fmt.Sprint(args...),
-			Severity: CtINFO,
-		})
-	} else {
-		grpclog.InfoDepth(1, args...)
-	}
-}
-
-// Infof logs through grpclog.Infof and adds a trace event if channelz is on.
-func Infof(id int64, format string, args ...interface{}) {
-	msg := fmt.Sprintf(format, args...)
-	if IsOn() {
-		AddTraceEvent(id, 1, &TraceEventDesc{
-			Desc:     msg,
-			Severity: CtINFO,
-		})
-	} else {
-		grpclog.InfoDepth(1, msg)
-	}
-}
-
-// Warning logs through grpclog.Warning and adds a trace event if channelz is on.
-func Warning(id int64, args ...interface{}) {
-	if IsOn() {
-		AddTraceEvent(id, 1, &TraceEventDesc{
-			Desc:     fmt.Sprint(args...),
-			Severity: CtWarning,
-		})
-	} else {
-		grpclog.WarningDepth(1, args...)
-	}
-}
-
-// Warningf logs through grpclog.Warningf and adds a trace event if channelz is on.
-func Warningf(id int64, format string, args ...interface{}) {
-	msg := fmt.Sprintf(format, args...)
-	if IsOn() {
-		AddTraceEvent(id, 1, &TraceEventDesc{
-			Desc:     msg,
-			Severity: CtWarning,
-		})
-	} else {
-		grpclog.WarningDepth(1, msg)
-	}
-}
-
-// Error logs through grpclog.Error and adds a trace event if channelz is on.
-func Error(id int64, args ...interface{}) {
-	if IsOn() {
-		AddTraceEvent(id, 1, &TraceEventDesc{
-			Desc:     fmt.Sprint(args...),
-			Severity: CtError,
-		})
-	} else {
-		grpclog.ErrorDepth(1, args...)
-	}
-}
-
-// Errorf logs through grpclog.Errorf and adds a trace event if channelz is on.
-func Errorf(id int64, format string, args ...interface{}) {
-	msg := fmt.Sprintf(format, args...)
-	if IsOn() {
-		AddTraceEvent(id, 1, &TraceEventDesc{
-			Desc:     msg,
-			Severity: CtError,
-		})
-	} else {
-		grpclog.ErrorDepth(1, msg)
-	}
-}
diff --git a/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go b/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go
index ae6c897..3ee8740 100644
--- a/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go
+++ b/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go
@@ -25,14 +25,11 @@
 )
 
 const (
-	prefix          = "GRPC_GO_"
-	retryStr        = prefix + "RETRY"
-	txtErrIgnoreStr = prefix + "IGNORE_TXT_ERRORS"
+	prefix   = "GRPC_GO_"
+	retryStr = prefix + "RETRY"
 )
 
 var (
 	// Retry is set if retry is explicitly enabled via "GRPC_GO_RETRY=on".
 	Retry = strings.EqualFold(os.Getenv(retryStr), "on")
-	// TXTErrIgnore is set if TXT errors should be ignored ("GRPC_GO_IGNORE_TXT_ERRORS" is not "false").
-	TXTErrIgnore = !strings.EqualFold(os.Getenv(retryStr), "false")
 )
diff --git a/vendor/google.golang.org/grpc/internal/grpclog/grpclog.go b/vendor/google.golang.org/grpc/internal/grpclog/grpclog.go
deleted file mode 100644
index 8c8e19f..0000000
--- a/vendor/google.golang.org/grpc/internal/grpclog/grpclog.go
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- *
- * Copyright 2020 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-// Package grpclog (internal) defines depth logging for grpc.
-package grpclog
-
-// Logger is the logger used for the non-depth log functions.
-var Logger LoggerV2
-
-// DepthLogger is the logger used for the depth log functions.
-var DepthLogger DepthLoggerV2
-
-// InfoDepth logs to the INFO log at the specified depth.
-func InfoDepth(depth int, args ...interface{}) {
-	if DepthLogger != nil {
-		DepthLogger.InfoDepth(depth, args...)
-	} else {
-		Logger.Info(args...)
-	}
-}
-
-// WarningDepth logs to the WARNING log at the specified depth.
-func WarningDepth(depth int, args ...interface{}) {
-	if DepthLogger != nil {
-		DepthLogger.WarningDepth(depth, args...)
-	} else {
-		Logger.Warning(args...)
-	}
-}
-
-// ErrorDepth logs to the ERROR log at the specified depth.
-func ErrorDepth(depth int, args ...interface{}) {
-	if DepthLogger != nil {
-		DepthLogger.ErrorDepth(depth, args...)
-	} else {
-		Logger.Error(args...)
-	}
-}
-
-// FatalDepth logs to the FATAL log at the specified depth.
-func FatalDepth(depth int, args ...interface{}) {
-	if DepthLogger != nil {
-		DepthLogger.FatalDepth(depth, args...)
-	} else {
-		Logger.Fatal(args...)
-	}
-}
-
-// LoggerV2 does underlying logging work for grpclog.
-// This is a copy of the LoggerV2 defined in the external grpclog package. It
-// is defined here to avoid a circular dependency.
-type LoggerV2 interface {
-	// Info logs to INFO log. Arguments are handled in the manner of fmt.Print.
-	Info(args ...interface{})
-	// Infoln logs to INFO log. Arguments are handled in the manner of fmt.Println.
-	Infoln(args ...interface{})
-	// Infof logs to INFO log. Arguments are handled in the manner of fmt.Printf.
-	Infof(format string, args ...interface{})
-	// Warning logs to WARNING log. Arguments are handled in the manner of fmt.Print.
-	Warning(args ...interface{})
-	// Warningln logs to WARNING log. Arguments are handled in the manner of fmt.Println.
-	Warningln(args ...interface{})
-	// Warningf logs to WARNING log. Arguments are handled in the manner of fmt.Printf.
-	Warningf(format string, args ...interface{})
-	// Error logs to ERROR log. Arguments are handled in the manner of fmt.Print.
-	Error(args ...interface{})
-	// Errorln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
-	Errorln(args ...interface{})
-	// Errorf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
-	Errorf(format string, args ...interface{})
-	// Fatal logs to ERROR log. Arguments are handled in the manner of fmt.Print.
-	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
-	// Implementations may also call os.Exit() with a non-zero exit code.
-	Fatal(args ...interface{})
-	// Fatalln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
-	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
-	// Implementations may also call os.Exit() with a non-zero exit code.
-	Fatalln(args ...interface{})
-	// Fatalf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
-	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
-	// Implementations may also call os.Exit() with a non-zero exit code.
-	Fatalf(format string, args ...interface{})
-	// V reports whether verbosity level l is at least the requested verbose level.
-	V(l int) bool
-}
-
-// DepthLoggerV2 logs at a specified call frame. If a LoggerV2 also implements
-// DepthLoggerV2, the below functions will be called with the appropriate stack
-// depth set for trivial functions the logger may ignore.
-// This is a copy of the DepthLoggerV2 defined in the external grpclog package.
-// It is defined here to avoid a circular dependency.
-//
-// This API is EXPERIMENTAL.
-type DepthLoggerV2 interface {
-	// InfoDepth logs to INFO log at the specified depth. Arguments are handled in the manner of fmt.Print.
-	InfoDepth(depth int, args ...interface{})
-	// WarningDepth logs to WARNING log at the specified depth. Arguments are handled in the manner of fmt.Print.
-	WarningDepth(depth int, args ...interface{})
-	// ErrorDetph logs to ERROR log at the specified depth. Arguments are handled in the manner of fmt.Print.
-	ErrorDepth(depth int, args ...interface{})
-	// FatalDepth logs to FATAL log at the specified depth. Arguments are handled in the manner of fmt.Print.
-	FatalDepth(depth int, args ...interface{})
-}
diff --git a/vendor/google.golang.org/grpc/internal/grpclog/prefixLogger.go b/vendor/google.golang.org/grpc/internal/grpclog/prefixLogger.go
deleted file mode 100644
index f6e0dc1..0000000
--- a/vendor/google.golang.org/grpc/internal/grpclog/prefixLogger.go
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- *
- * Copyright 2020 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-package grpclog
-
-// PrefixLogger does logging with a prefix.
-//
-// Logging method on a nil logs without any prefix.
-type PrefixLogger struct {
-	prefix string
-}
-
-// Infof does info logging.
-func (pl *PrefixLogger) Infof(format string, args ...interface{}) {
-	if pl != nil {
-		// Handle nil, so the tests can pass in a nil logger.
-		format = pl.prefix + format
-	}
-	Logger.Infof(format, args...)
-}
-
-// Warningf does warning logging.
-func (pl *PrefixLogger) Warningf(format string, args ...interface{}) {
-	if pl != nil {
-		format = pl.prefix + format
-	}
-	Logger.Warningf(format, args...)
-}
-
-// Errorf does error logging.
-func (pl *PrefixLogger) Errorf(format string, args ...interface{}) {
-	if pl != nil {
-		format = pl.prefix + format
-	}
-	Logger.Errorf(format, args...)
-}
-
-// Debugf does info logging at verbose level 2.
-func (pl *PrefixLogger) Debugf(format string, args ...interface{}) {
-	if Logger.V(2) {
-		pl.Infof(format, args...)
-	}
-}
-
-// NewPrefixLogger creates a prefix logger with the given prefix.
-func NewPrefixLogger(prefix string) *PrefixLogger {
-	return &PrefixLogger{prefix: prefix}
-}
diff --git a/vendor/google.golang.org/grpc/internal/grpcutil/target.go b/vendor/google.golang.org/grpc/internal/grpcutil/target.go
deleted file mode 100644
index 80b33cd..0000000
--- a/vendor/google.golang.org/grpc/internal/grpcutil/target.go
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
- *
- * Copyright 2020 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-// Package grpcutil provides a bunch of utility functions to be used across the
-// gRPC codebase.
-package grpcutil
-
-import (
-	"strings"
-
-	"google.golang.org/grpc/resolver"
-)
-
-// split2 returns the values from strings.SplitN(s, sep, 2).
-// If sep is not found, it returns ("", "", false) instead.
-func split2(s, sep string) (string, string, bool) {
-	spl := strings.SplitN(s, sep, 2)
-	if len(spl) < 2 {
-		return "", "", false
-	}
-	return spl[0], spl[1], true
-}
-
-// ParseTarget splits target into a resolver.Target struct containing scheme,
-// authority and endpoint.
-//
-// If target is not a valid scheme://authority/endpoint, it returns {Endpoint:
-// target}.
-func ParseTarget(target string) (ret resolver.Target) {
-	var ok bool
-	ret.Scheme, ret.Endpoint, ok = split2(target, "://")
-	if !ok {
-		return resolver.Target{Endpoint: target}
-	}
-	ret.Authority, ret.Endpoint, ok = split2(ret.Endpoint, "/")
-	if !ok {
-		return resolver.Target{Endpoint: target}
-	}
-	return ret
-}
diff --git a/vendor/google.golang.org/grpc/internal/internal.go b/vendor/google.golang.org/grpc/internal/internal.go
index c6fbe8b..b96b359 100644
--- a/vendor/google.golang.org/grpc/internal/internal.go
+++ b/vendor/google.golang.org/grpc/internal/internal.go
@@ -28,6 +28,8 @@
 )
 
 var (
+	// WithResolverBuilder is set by dialoptions.go
+	WithResolverBuilder interface{} // func (resolver.Builder) grpc.DialOption
 	// WithHealthCheckFunc is set by dialoptions.go
 	WithHealthCheckFunc interface{} // func (HealthChecker) DialOption
 	// HealthCheckFunc is used to provide client-side LB channel health checking
@@ -37,6 +39,11 @@
 	// KeepaliveMinPingTime is the minimum ping interval.  This must be 10s by
 	// default, but tests may wish to set it lower for convenience.
 	KeepaliveMinPingTime = 10 * time.Second
+	// StatusRawProto is exported by status/status.go. This func returns a
+	// pointer to the wrapped Status proto for a given status.Status without a
+	// call to proto.Clone(). The returned Status proto should not be mutated by
+	// the caller.
+	StatusRawProto interface{} // func (*status.Status) *spb.Status
 	// NewRequestInfoContext creates a new context based on the argument context attaching
 	// the passed in RequestInfo to the new context.
 	NewRequestInfoContext interface{} // func(context.Context, credentials.RequestInfo) context.Context
@@ -53,7 +60,7 @@
 //
 // The health checking protocol is defined at:
 // https://github.com/grpc/grpc/blob/master/doc/health-checking.md
-type HealthChecker func(ctx context.Context, newStream func(string) (interface{}, error), setConnectivityState func(connectivity.State, error), serviceName string) error
+type HealthChecker func(ctx context.Context, newStream func(string) (interface{}, error), setConnectivityState func(connectivity.State), serviceName string) error
 
 const (
 	// CredsBundleModeFallback switches GoogleDefaultCreds to fallback mode.
diff --git a/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go b/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go
index c368db6..abc0f92 100644
--- a/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go
+++ b/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go
@@ -32,23 +32,20 @@
 	"sync"
 	"time"
 
+	"google.golang.org/grpc/backoff"
 	"google.golang.org/grpc/grpclog"
-	"google.golang.org/grpc/internal/envconfig"
+	internalbackoff "google.golang.org/grpc/internal/backoff"
 	"google.golang.org/grpc/internal/grpcrand"
 	"google.golang.org/grpc/resolver"
-	"google.golang.org/grpc/serviceconfig"
 )
 
-// EnableSRVLookups controls whether the DNS resolver attempts to fetch gRPCLB
-// addresses from SRV records.  Must not be changed after init time.
-var EnableSRVLookups = false
-
 func init() {
 	resolver.Register(NewBuilder())
 }
 
 const (
 	defaultPort       = "443"
+	defaultFreq       = time.Minute * 30
 	defaultDNSSvrPort = "53"
 	golang            = "GO"
 	// txtPrefix is the prefix string to be prepended to the host name for txt record lookup.
@@ -98,33 +95,49 @@
 
 // NewBuilder creates a dnsBuilder which is used to factory DNS resolvers.
 func NewBuilder() resolver.Builder {
-	return &dnsBuilder{}
+	return &dnsBuilder{minFreq: defaultFreq}
 }
 
-type dnsBuilder struct{}
+type dnsBuilder struct {
+	// minimum frequency of polling the DNS server.
+	minFreq time.Duration
+}
 
 // Build creates and starts a DNS resolver that watches the name resolution of the target.
-func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
+func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOption) (resolver.Resolver, error) {
 	host, port, err := parseTarget(target.Endpoint, defaultPort)
 	if err != nil {
 		return nil, err
 	}
 
 	// IP address.
-	if ipAddr, ok := formatIP(host); ok {
-		addr := []resolver.Address{{Addr: ipAddr + ":" + port}}
-		cc.UpdateState(resolver.State{Addresses: addr})
-		return deadResolver{}, nil
+	if net.ParseIP(host) != nil {
+		host, _ = formatIP(host)
+		addr := []resolver.Address{{Addr: host + ":" + port}}
+		i := &ipResolver{
+			cc: cc,
+			ip: addr,
+			rn: make(chan struct{}, 1),
+			q:  make(chan struct{}),
+		}
+		cc.NewAddress(addr)
+		go i.watcher()
+		return i, nil
 	}
 
 	// DNS address (non-IP).
 	ctx, cancel := context.WithCancel(context.Background())
+	bc := backoff.DefaultConfig
+	bc.MaxDelay = b.minFreq
 	d := &dnsResolver{
+		freq:                 b.minFreq,
+		backoff:              internalbackoff.Exponential{Config: bc},
 		host:                 host,
 		port:                 port,
 		ctx:                  ctx,
 		cancel:               cancel,
 		cc:                   cc,
+		t:                    time.NewTimer(0),
 		rn:                   make(chan struct{}, 1),
 		disableServiceConfig: opts.DisableServiceConfig,
 	}
@@ -140,7 +153,6 @@
 
 	d.wg.Add(1)
 	go d.watcher()
-	d.ResolveNow(resolver.ResolveNowOptions{})
 	return d, nil
 }
 
@@ -155,23 +167,53 @@
 	LookupTXT(ctx context.Context, name string) (txts []string, err error)
 }
 
-// deadResolver is a resolver that does nothing.
-type deadResolver struct{}
+// ipResolver watches for the name resolution update for an IP address.
+type ipResolver struct {
+	cc resolver.ClientConn
+	ip []resolver.Address
+	// rn channel is used by ResolveNow() to force an immediate resolution of the target.
+	rn chan struct{}
+	q  chan struct{}
+}
 
-func (deadResolver) ResolveNow(resolver.ResolveNowOptions) {}
+// ResolveNow resend the address it stores, no resolution is needed.
+func (i *ipResolver) ResolveNow(opt resolver.ResolveNowOption) {
+	select {
+	case i.rn <- struct{}{}:
+	default:
+	}
+}
 
-func (deadResolver) Close() {}
+// Close closes the ipResolver.
+func (i *ipResolver) Close() {
+	close(i.q)
+}
+
+func (i *ipResolver) watcher() {
+	for {
+		select {
+		case <-i.rn:
+			i.cc.NewAddress(i.ip)
+		case <-i.q:
+			return
+		}
+	}
+}
 
 // dnsResolver watches for the name resolution update for a non-IP target.
 type dnsResolver struct {
-	host     string
-	port     string
-	resolver netResolver
-	ctx      context.Context
-	cancel   context.CancelFunc
-	cc       resolver.ClientConn
+	freq       time.Duration
+	backoff    internalbackoff.Exponential
+	retryCount int
+	host       string
+	port       string
+	resolver   netResolver
+	ctx        context.Context
+	cancel     context.CancelFunc
+	cc         resolver.ClientConn
 	// rn channel is used by ResolveNow() to force an immediate resolution of the target.
 	rn chan struct{}
+	t  *time.Timer
 	// wg is used to enforce Close() to return after the watcher() goroutine has finished.
 	// Otherwise, data race will be possible. [Race Example] in dns_resolver_test we
 	// replace the real lookup functions with mocked ones to facilitate testing.
@@ -183,7 +225,7 @@
 }
 
 // ResolveNow invoke an immediate resolution of the target that this dnsResolver watches.
-func (d *dnsResolver) ResolveNow(resolver.ResolveNowOptions) {
+func (d *dnsResolver) ResolveNow(opt resolver.ResolveNowOption) {
 	select {
 	case d.rn <- struct{}{}:
 	default:
@@ -194,6 +236,7 @@
 func (d *dnsResolver) Close() {
 	d.cancel()
 	d.wg.Wait()
+	d.t.Stop()
 }
 
 func (d *dnsResolver) watcher() {
@@ -202,15 +245,27 @@
 		select {
 		case <-d.ctx.Done():
 			return
+		case <-d.t.C:
 		case <-d.rn:
+			if !d.t.Stop() {
+				// Before resetting a timer, it should be stopped to prevent racing with
+				// reads on it's channel.
+				<-d.t.C
+			}
 		}
 
-		state, err := d.lookup()
-		if err != nil {
-			d.cc.ReportError(err)
+		result, sc := d.lookup()
+		// Next lookup should happen within an interval defined by d.freq. It may be
+		// more often due to exponential retry on empty address list.
+		if len(result) == 0 {
+			d.retryCount++
+			d.t.Reset(d.backoff.Backoff(d.retryCount))
 		} else {
-			d.cc.UpdateState(*state)
+			d.retryCount = 0
+			d.t.Reset(d.freq)
 		}
+		d.cc.NewServiceConfig(sc)
+		d.cc.NewAddress(result)
 
 		// Sleep to prevent excessive re-resolutions. Incoming resolution requests
 		// will be queued in d.rn.
@@ -224,68 +279,37 @@
 	}
 }
 
-func (d *dnsResolver) lookupSRV() ([]resolver.Address, error) {
-	if !EnableSRVLookups {
-		return nil, nil
-	}
+func (d *dnsResolver) lookupSRV() []resolver.Address {
 	var newAddrs []resolver.Address
 	_, srvs, err := d.resolver.LookupSRV(d.ctx, "grpclb", "tcp", d.host)
 	if err != nil {
-		err = handleDNSError(err, "SRV") // may become nil
-		return nil, err
+		grpclog.Infof("grpc: failed dns SRV record lookup due to %v.\n", err)
+		return nil
 	}
 	for _, s := range srvs {
 		lbAddrs, err := d.resolver.LookupHost(d.ctx, s.Target)
 		if err != nil {
-			err = handleDNSError(err, "A") // may become nil
-			if err == nil {
-				// If there are other SRV records, look them up and ignore this
-				// one that does not exist.
-				continue
-			}
-			return nil, err
+			grpclog.Infof("grpc: failed load balancer address dns lookup due to %v.\n", err)
+			continue
 		}
 		for _, a := range lbAddrs {
-			ip, ok := formatIP(a)
+			a, ok := formatIP(a)
 			if !ok {
-				return nil, fmt.Errorf("dns: error parsing A record IP address %v", a)
+				grpclog.Errorf("grpc: failed IP parsing due to %v.\n", err)
+				continue
 			}
-			addr := ip + ":" + strconv.Itoa(int(s.Port))
+			addr := a + ":" + strconv.Itoa(int(s.Port))
 			newAddrs = append(newAddrs, resolver.Address{Addr: addr, Type: resolver.GRPCLB, ServerName: s.Target})
 		}
 	}
-	return newAddrs, nil
+	return newAddrs
 }
 
-var filterError = func(err error) error {
-	if dnsErr, ok := err.(*net.DNSError); ok && !dnsErr.IsTimeout && !dnsErr.IsTemporary {
-		// Timeouts and temporary errors should be communicated to gRPC to
-		// attempt another DNS query (with backoff).  Other errors should be
-		// suppressed (they may represent the absence of a TXT record).
-		return nil
-	}
-	return err
-}
-
-func handleDNSError(err error, lookupType string) error {
-	err = filterError(err)
-	if err != nil {
-		err = fmt.Errorf("dns: %v record lookup error: %v", lookupType, err)
-		grpclog.Infoln(err)
-	}
-	return err
-}
-
-func (d *dnsResolver) lookupTXT() *serviceconfig.ParseResult {
+func (d *dnsResolver) lookupTXT() string {
 	ss, err := d.resolver.LookupTXT(d.ctx, txtPrefix+d.host)
 	if err != nil {
-		if envconfig.TXTErrIgnore {
-			return nil
-		}
-		if err = handleDNSError(err, "TXT"); err != nil {
-			return &serviceconfig.ParseResult{Err: err}
-		}
-		return nil
+		grpclog.Infof("grpc: failed dns TXT record lookup due to %v.\n", err)
+		return ""
 	}
 	var res string
 	for _, s := range ss {
@@ -294,45 +318,40 @@
 
 	// TXT record must have "grpc_config=" attribute in order to be used as service config.
 	if !strings.HasPrefix(res, txtAttribute) {
-		grpclog.Warningf("dns: TXT record %v missing %v attribute", res, txtAttribute)
-		// This is not an error; it is the equivalent of not having a service config.
-		return nil
+		grpclog.Warningf("grpc: TXT record %v missing %v attribute", res, txtAttribute)
+		return ""
 	}
-	sc := canaryingSC(strings.TrimPrefix(res, txtAttribute))
-	return d.cc.ParseServiceConfig(sc)
+	return strings.TrimPrefix(res, txtAttribute)
 }
 
-func (d *dnsResolver) lookupHost() ([]resolver.Address, error) {
+func (d *dnsResolver) lookupHost() []resolver.Address {
 	var newAddrs []resolver.Address
 	addrs, err := d.resolver.LookupHost(d.ctx, d.host)
 	if err != nil {
-		err = handleDNSError(err, "A")
-		return nil, err
+		grpclog.Warningf("grpc: failed dns A record lookup due to %v.\n", err)
+		return nil
 	}
 	for _, a := range addrs {
-		ip, ok := formatIP(a)
+		a, ok := formatIP(a)
 		if !ok {
-			return nil, fmt.Errorf("dns: error parsing A record IP address %v", a)
+			grpclog.Errorf("grpc: failed IP parsing due to %v.\n", err)
+			continue
 		}
-		addr := ip + ":" + d.port
+		addr := a + ":" + d.port
 		newAddrs = append(newAddrs, resolver.Address{Addr: addr})
 	}
-	return newAddrs, nil
+	return newAddrs
 }
 
-func (d *dnsResolver) lookup() (*resolver.State, error) {
-	srv, srvErr := d.lookupSRV()
-	addrs, hostErr := d.lookupHost()
-	if hostErr != nil && (srvErr != nil || len(srv) == 0) {
-		return nil, hostErr
+func (d *dnsResolver) lookup() ([]resolver.Address, string) {
+	newAddrs := d.lookupSRV()
+	// Support fallback to non-balancer address.
+	newAddrs = append(newAddrs, d.lookupHost()...)
+	if d.disableServiceConfig {
+		return newAddrs, ""
 	}
-	state := &resolver.State{
-		Addresses: append(addrs, srv...),
-	}
-	if !d.disableServiceConfig {
-		state.ServiceConfig = d.lookupTXT()
-	}
-	return state, nil
+	sc := d.lookupTXT()
+	return newAddrs, canaryingSC(sc)
 }
 
 // formatIP returns ok = false if addr is not a valid textual representation of an IP address.
@@ -418,12 +437,12 @@
 	var rcs []rawChoice
 	err := json.Unmarshal([]byte(js), &rcs)
 	if err != nil {
-		grpclog.Warningf("dns: error parsing service config json: %v", err)
+		grpclog.Warningf("grpc: failed to parse service config json string due to %v.\n", err)
 		return ""
 	}
 	cliHostname, err := os.Hostname()
 	if err != nil {
-		grpclog.Warningf("dns: error getting client hostname: %v", err)
+		grpclog.Warningf("grpc: failed to get client hostname due to %v.\n", err)
 		return ""
 	}
 	var sc string
diff --git a/vendor/google.golang.org/grpc/internal/resolver/dns/go113.go b/vendor/google.golang.org/grpc/internal/resolver/dns/go113.go
deleted file mode 100644
index 8783a8c..0000000
--- a/vendor/google.golang.org/grpc/internal/resolver/dns/go113.go
+++ /dev/null
@@ -1,33 +0,0 @@
-// +build go1.13
-
-/*
- *
- * Copyright 2019 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-package dns
-
-import "net"
-
-func init() {
-	filterError = func(err error) error {
-		if dnsErr, ok := err.(*net.DNSError); ok && dnsErr.IsNotFound {
-			// The name does not exist; not an error.
-			return nil
-		}
-		return err
-	}
-}
diff --git a/vendor/google.golang.org/grpc/internal/resolver/passthrough/passthrough.go b/vendor/google.golang.org/grpc/internal/resolver/passthrough/passthrough.go
index 520d922..893d5d1 100644
--- a/vendor/google.golang.org/grpc/internal/resolver/passthrough/passthrough.go
+++ b/vendor/google.golang.org/grpc/internal/resolver/passthrough/passthrough.go
@@ -26,7 +26,7 @@
 
 type passthroughBuilder struct{}
 
-func (*passthroughBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
+func (*passthroughBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOption) (resolver.Resolver, error) {
 	r := &passthroughResolver{
 		target: target,
 		cc:     cc,
@@ -48,7 +48,7 @@
 	r.cc.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: r.target.Endpoint}}})
 }
 
-func (*passthroughResolver) ResolveNow(o resolver.ResolveNowOptions) {}
+func (*passthroughResolver) ResolveNow(o resolver.ResolveNowOption) {}
 
 func (*passthroughResolver) Close() {}
 
diff --git a/vendor/google.golang.org/grpc/internal/status/status.go b/vendor/google.golang.org/grpc/internal/status/status.go
deleted file mode 100644
index 6812606..0000000
--- a/vendor/google.golang.org/grpc/internal/status/status.go
+++ /dev/null
@@ -1,161 +0,0 @@
-/*
- *
- * Copyright 2020 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-// Package status implements errors returned by gRPC.  These errors are
-// serialized and transmitted on the wire between server and client, and allow
-// for additional data to be transmitted via the Details field in the status
-// proto.  gRPC service handlers should return an error created by this
-// package, and gRPC clients should expect a corresponding error to be
-// returned from the RPC call.
-//
-// This package upholds the invariants that a non-nil error may not
-// contain an OK code, and an OK code must result in a nil error.
-package status
-
-import (
-	"errors"
-	"fmt"
-
-	"github.com/golang/protobuf/proto"
-	"github.com/golang/protobuf/ptypes"
-	spb "google.golang.org/genproto/googleapis/rpc/status"
-	"google.golang.org/grpc/codes"
-)
-
-// Status represents an RPC status code, message, and details.  It is immutable
-// and should be created with New, Newf, or FromProto.
-type Status struct {
-	s *spb.Status
-}
-
-// New returns a Status representing c and msg.
-func New(c codes.Code, msg string) *Status {
-	return &Status{s: &spb.Status{Code: int32(c), Message: msg}}
-}
-
-// Newf returns New(c, fmt.Sprintf(format, a...)).
-func Newf(c codes.Code, format string, a ...interface{}) *Status {
-	return New(c, fmt.Sprintf(format, a...))
-}
-
-// FromProto returns a Status representing s.
-func FromProto(s *spb.Status) *Status {
-	return &Status{s: proto.Clone(s).(*spb.Status)}
-}
-
-// Err returns an error representing c and msg.  If c is OK, returns nil.
-func Err(c codes.Code, msg string) error {
-	return New(c, msg).Err()
-}
-
-// Errorf returns Error(c, fmt.Sprintf(format, a...)).
-func Errorf(c codes.Code, format string, a ...interface{}) error {
-	return Err(c, fmt.Sprintf(format, a...))
-}
-
-// Code returns the status code contained in s.
-func (s *Status) Code() codes.Code {
-	if s == nil || s.s == nil {
-		return codes.OK
-	}
-	return codes.Code(s.s.Code)
-}
-
-// Message returns the message contained in s.
-func (s *Status) Message() string {
-	if s == nil || s.s == nil {
-		return ""
-	}
-	return s.s.Message
-}
-
-// Proto returns s's status as an spb.Status proto message.
-func (s *Status) Proto() *spb.Status {
-	if s == nil {
-		return nil
-	}
-	return proto.Clone(s.s).(*spb.Status)
-}
-
-// Err returns an immutable error representing s; returns nil if s.Code() is OK.
-func (s *Status) Err() error {
-	if s.Code() == codes.OK {
-		return nil
-	}
-	return (*Error)(s.Proto())
-}
-
-// WithDetails returns a new status with the provided details messages appended to the status.
-// If any errors are encountered, it returns nil and the first error encountered.
-func (s *Status) WithDetails(details ...proto.Message) (*Status, error) {
-	if s.Code() == codes.OK {
-		return nil, errors.New("no error details for status with code OK")
-	}
-	// s.Code() != OK implies that s.Proto() != nil.
-	p := s.Proto()
-	for _, detail := range details {
-		any, err := ptypes.MarshalAny(detail)
-		if err != nil {
-			return nil, err
-		}
-		p.Details = append(p.Details, any)
-	}
-	return &Status{s: p}, nil
-}
-
-// Details returns a slice of details messages attached to the status.
-// If a detail cannot be decoded, the error is returned in place of the detail.
-func (s *Status) Details() []interface{} {
-	if s == nil || s.s == nil {
-		return nil
-	}
-	details := make([]interface{}, 0, len(s.s.Details))
-	for _, any := range s.s.Details {
-		detail := &ptypes.DynamicAny{}
-		if err := ptypes.UnmarshalAny(any, detail); err != nil {
-			details = append(details, err)
-			continue
-		}
-		details = append(details, detail.Message)
-	}
-	return details
-}
-
-// Error is an alias of a status proto. It implements error and Status,
-// and a nil Error should never be returned by this package.
-type Error spb.Status
-
-func (se *Error) Error() string {
-	p := (*spb.Status)(se)
-	return fmt.Sprintf("rpc error: code = %s desc = %s", codes.Code(p.GetCode()), p.GetMessage())
-}
-
-// GRPCStatus returns the Status represented by se.
-func (se *Error) GRPCStatus() *Status {
-	return FromProto((*spb.Status)(se))
-}
-
-// Is implements future error.Is functionality.
-// A Error is equivalent if the code and message are identical.
-func (se *Error) Is(target error) bool {
-	tse, ok := target.(*Error)
-	if !ok {
-		return false
-	}
-	return proto.Equal((*spb.Status)(se), (*spb.Status)(tse))
-}
diff --git a/vendor/google.golang.org/grpc/internal/transport/handler_server.go b/vendor/google.golang.org/grpc/internal/transport/handler_server.go
index fc44e97..78f9ddc 100644
--- a/vendor/google.golang.org/grpc/internal/transport/handler_server.go
+++ b/vendor/google.golang.org/grpc/internal/transport/handler_server.go
@@ -112,10 +112,11 @@
 // at this point to be speaking over HTTP/2, so it's able to speak valid
 // gRPC.
 type serverHandlerTransport struct {
-	rw         http.ResponseWriter
-	req        *http.Request
-	timeoutSet bool
-	timeout    time.Duration
+	rw               http.ResponseWriter
+	req              *http.Request
+	timeoutSet       bool
+	timeout          time.Duration
+	didCommonHeaders bool
 
 	headerMD metadata.MD
 
@@ -185,11 +186,8 @@
 	ht.writeStatusMu.Lock()
 	defer ht.writeStatusMu.Unlock()
 
-	headersWritten := s.updateHeaderSent()
 	err := ht.do(func() {
-		if !headersWritten {
-			ht.writePendingHeaders(s)
-		}
+		ht.writeCommonHeaders(s)
 
 		// And flush, in case no header or body has been sent yet.
 		// This forces a separation of headers and trailers if this is the
@@ -229,27 +227,21 @@
 
 	if err == nil { // transport has not been closed
 		if ht.stats != nil {
-			// Note: The trailer fields are compressed with hpack after this call returns.
-			// No WireLength field is set here.
-			ht.stats.HandleRPC(s.Context(), &stats.OutTrailer{
-				Trailer: s.trailer.Copy(),
-			})
+			ht.stats.HandleRPC(s.Context(), &stats.OutTrailer{})
 		}
 	}
 	ht.Close()
 	return err
 }
 
-// writePendingHeaders sets common and custom headers on the first
-// write call (Write, WriteHeader, or WriteStatus)
-func (ht *serverHandlerTransport) writePendingHeaders(s *Stream) {
-	ht.writeCommonHeaders(s)
-	ht.writeCustomHeaders(s)
-}
-
 // writeCommonHeaders sets common headers on the first write
 // call (Write, WriteHeader, or WriteStatus).
 func (ht *serverHandlerTransport) writeCommonHeaders(s *Stream) {
+	if ht.didCommonHeaders {
+		return
+	}
+	ht.didCommonHeaders = true
+
 	h := ht.rw.Header()
 	h["Date"] = nil // suppress Date to make tests happy; TODO: restore
 	h.Set("Content-Type", ht.contentType)
@@ -268,30 +260,9 @@
 	}
 }
 
-// writeCustomHeaders sets custom headers set on the stream via SetHeader
-// on the first write call (Write, WriteHeader, or WriteStatus).
-func (ht *serverHandlerTransport) writeCustomHeaders(s *Stream) {
-	h := ht.rw.Header()
-
-	s.hdrMu.Lock()
-	for k, vv := range s.header {
-		if isReservedHeader(k) {
-			continue
-		}
-		for _, v := range vv {
-			h.Add(k, encodeMetadataHeader(k, v))
-		}
-	}
-
-	s.hdrMu.Unlock()
-}
-
 func (ht *serverHandlerTransport) Write(s *Stream, hdr []byte, data []byte, opts *Options) error {
-	headersWritten := s.updateHeaderSent()
 	return ht.do(func() {
-		if !headersWritten {
-			ht.writePendingHeaders(s)
-		}
+		ht.writeCommonHeaders(s)
 		ht.rw.Write(hdr)
 		ht.rw.Write(data)
 		ht.rw.(http.Flusher).Flush()
@@ -299,28 +270,26 @@
 }
 
 func (ht *serverHandlerTransport) WriteHeader(s *Stream, md metadata.MD) error {
-	if err := s.SetHeader(md); err != nil {
-		return err
-	}
-
-	headersWritten := s.updateHeaderSent()
 	err := ht.do(func() {
-		if !headersWritten {
-			ht.writePendingHeaders(s)
+		ht.writeCommonHeaders(s)
+		h := ht.rw.Header()
+		for k, vv := range md {
+			// Clients don't tolerate reading restricted headers after some non restricted ones were sent.
+			if isReservedHeader(k) {
+				continue
+			}
+			for _, v := range vv {
+				v = encodeMetadataHeader(k, v)
+				h.Add(k, v)
+			}
 		}
-
 		ht.rw.WriteHeader(200)
 		ht.rw.(http.Flusher).Flush()
 	})
 
 	if err == nil {
 		if ht.stats != nil {
-			// Note: The header fields are compressed with hpack after this call returns.
-			// No WireLength field is set here.
-			ht.stats.HandleRPC(s.Context(), &stats.OutHeader{
-				Header:      md.Copy(),
-				Compression: s.sendCompress,
-			})
+			ht.stats.HandleRPC(s.Context(), &stats.OutHeader{})
 		}
 	}
 	return err
@@ -365,7 +334,7 @@
 		Addr: ht.RemoteAddr(),
 	}
 	if req.TLS != nil {
-		pr.AuthInfo = credentials.TLSInfo{State: *req.TLS, CommonAuthInfo: credentials.CommonAuthInfo{SecurityLevel: credentials.PrivacyAndIntegrity}}
+		pr.AuthInfo = credentials.TLSInfo{State: *req.TLS}
 	}
 	ctx = metadata.NewIncomingContext(ctx, ht.headerMD)
 	s.ctx = peer.NewContext(ctx, pr)
diff --git a/vendor/google.golang.org/grpc/internal/transport/http2_client.go b/vendor/google.golang.org/grpc/internal/transport/http2_client.go
index 1cc586f..294661a 100644
--- a/vendor/google.golang.org/grpc/internal/transport/http2_client.go
+++ b/vendor/google.golang.org/grpc/internal/transport/http2_client.go
@@ -45,14 +45,9 @@
 	"google.golang.org/grpc/status"
 )
 
-// clientConnectionCounter counts the number of connections a client has
-// initiated (equal to the number of http2Clients created). Must be accessed
-// atomically.
-var clientConnectionCounter uint64
-
 // http2Client implements the ClientTransport interface with HTTP2.
 type http2Client struct {
-	lastRead   int64 // Keep this field 64-bit aligned. Accessed atomically.
+	lastRead   int64 // keep this field 64-bit aligned
 	ctx        context.Context
 	cancel     context.CancelFunc
 	ctxDone    <-chan struct{} // Cache the ctx.Done() chan.
@@ -131,8 +126,6 @@
 	onClose  func()
 
 	bufferPool *bufferPool
-
-	connectionID uint64
 }
 
 func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error), addr string) (net.Conn, error) {
@@ -336,8 +329,6 @@
 		}
 	}
 
-	t.connectionID = atomic.AddUint64(&clientConnectionCounter, 1)
-
 	if err := t.framer.writer.Flush(); err != nil {
 		return nil, err
 	}
@@ -403,8 +394,7 @@
 func (t *http2Client) createHeaderFields(ctx context.Context, callHdr *CallHdr) ([]hpack.HeaderField, error) {
 	aud := t.createAudience(callHdr)
 	ri := credentials.RequestInfo{
-		Method:   callHdr.Method,
-		AuthInfo: t.authInfo,
+		Method: callHdr.Method,
 	}
 	ctxWithRequestInfo := internal.NewRequestInfoContext.(func(context.Context, credentials.RequestInfo) context.Context)(ctx, ri)
 	authData, err := t.getTrAuthData(ctxWithRequestInfo, aud)
@@ -434,7 +424,6 @@
 
 	if callHdr.SendCompress != "" {
 		headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-encoding", Value: callHdr.SendCompress})
-		headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-accept-encoding", Value: callHdr.SendCompress})
 	}
 	if dl, ok := ctx.Deadline(); ok {
 		// Send out timeout regardless its value. The server can detect timeout context by itself.
@@ -680,21 +669,12 @@
 		}
 	}
 	if t.statsHandler != nil {
-		header, ok := metadata.FromOutgoingContext(ctx)
-		if ok {
-			header.Set("user-agent", t.userAgent)
-		} else {
-			header = metadata.Pairs("user-agent", t.userAgent)
-		}
-		// Note: The header fields are compressed with hpack after this call returns.
-		// No WireLength field is set here.
 		outHeader := &stats.OutHeader{
 			Client:      true,
 			FullMethod:  callHdr.Method,
 			RemoteAddr:  t.remoteAddr,
 			LocalAddr:   t.localAddr,
 			Compression: callHdr.SendCompress,
-			Header:      header,
 		}
 		t.statsHandler.HandleRPC(s.ctx, outHeader)
 	}
@@ -1195,17 +1175,14 @@
 		if t.statsHandler != nil {
 			if isHeader {
 				inHeader := &stats.InHeader{
-					Client:      true,
-					WireLength:  int(frame.Header().Length),
-					Header:      s.header.Copy(),
-					Compression: s.recvCompress,
+					Client:     true,
+					WireLength: int(frame.Header().Length),
 				}
 				t.statsHandler.HandleRPC(s.ctx, inHeader)
 			} else {
 				inTrailer := &stats.InTrailer{
 					Client:     true,
 					WireLength: int(frame.Header().Length),
-					Trailer:    s.trailer.Copy(),
 				}
 				t.statsHandler.HandleRPC(s.ctx, inTrailer)
 			}
@@ -1392,6 +1369,7 @@
 			// acked).
 			sleepDuration := minTime(t.kp.Time, timeoutLeft)
 			timeoutLeft -= sleepDuration
+			prevNano = lastRead
 			timer.Reset(sleepDuration)
 		case <-t.ctx.Done():
 			if !timer.Stop() {
diff --git a/vendor/google.golang.org/grpc/internal/transport/http2_server.go b/vendor/google.golang.org/grpc/internal/transport/http2_server.go
index fa33ffb..0760383 100644
--- a/vendor/google.golang.org/grpc/internal/transport/http2_server.go
+++ b/vendor/google.golang.org/grpc/internal/transport/http2_server.go
@@ -35,9 +35,11 @@
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
 
+	spb "google.golang.org/genproto/googleapis/rpc/status"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/grpcrand"
 	"google.golang.org/grpc/keepalive"
@@ -55,15 +57,13 @@
 	// ErrHeaderListSizeLimitViolation indicates that the header list size is larger
 	// than the limit set by peer.
 	ErrHeaderListSizeLimitViolation = errors.New("transport: trying to send header list size larger than the limit set by peer")
+	// statusRawProto is a function to get to the raw status proto wrapped in a
+	// status.Status without a proto.Clone().
+	statusRawProto = internal.StatusRawProto.(func(*status.Status) *spb.Status)
 )
 
-// serverConnectionCounter counts the number of connections a server has seen
-// (equal to the number of http2Servers created). Must be accessed atomically.
-var serverConnectionCounter uint64
-
 // http2Server implements the ServerTransport interface with HTTP2.
 type http2Server struct {
-	lastRead    int64 // Keep this field 64-bit aligned. Accessed atomically.
 	ctx         context.Context
 	done        chan struct{}
 	conn        net.Conn
@@ -83,8 +83,12 @@
 	controlBuf *controlBuffer
 	fc         *trInFlow
 	stats      stats.Handler
+	// Flag to keep track of reading activity on transport.
+	// 1 is true and 0 is false.
+	activity uint32 // Accessed atomically.
 	// Keepalive and max-age parameters for the server.
 	kp keepalive.ServerParameters
+
 	// Keepalive enforcement policy.
 	kep keepalive.EnforcementPolicy
 	// The time instance last ping was received.
@@ -120,8 +124,6 @@
 	channelzID int64 // channelz unique identification number
 	czData     *channelzData
 	bufferPool *bufferPool
-
-	connectionID uint64
 }
 
 // newHTTP2Server constructs a ServerTransport based on HTTP2. ConnectionError is
@@ -251,9 +253,6 @@
 	if channelz.IsOn() {
 		t.channelzID = channelz.RegisterNormalSocket(t, config.ChannelzParentID, fmt.Sprintf("%s -> %s", t.remoteAddr, t.localAddr))
 	}
-
-	t.connectionID = atomic.AddUint64(&serverConnectionCounter, 1)
-
 	t.framer.writer.Flush()
 
 	defer func() {
@@ -278,7 +277,7 @@
 	if err != nil {
 		return nil, connectionErrorf(false, err, "transport: http2Server.HandleStreams failed to read initial settings frame: %v", err)
 	}
-	atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
+	atomic.StoreUint32(&t.activity, 1)
 	sf, ok := frame.(*http2.SettingsFrame)
 	if !ok {
 		return nil, connectionErrorf(false, nil, "transport: http2Server.HandleStreams saw invalid preface type %T from client", frame)
@@ -417,7 +416,6 @@
 			LocalAddr:   t.localAddr,
 			Compression: s.recvCompress,
 			WireLength:  int(frame.Header().Length),
-			Header:      metadata.MD(state.data.mdata).Copy(),
 		}
 		t.stats.HandleRPC(s.ctx, inHeader)
 	}
@@ -451,7 +449,7 @@
 	for {
 		t.controlBuf.throttle()
 		frame, err := t.framer.fr.ReadFrame()
-		atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
+		atomic.StoreUint32(&t.activity, 1)
 		if err != nil {
 			if se, ok := err.(http2.StreamError); ok {
 				warningf("transport: http2Server.HandleStreams encountered http2.StreamError: %v", se)
@@ -808,12 +806,9 @@
 		return ErrHeaderListSizeLimitViolation
 	}
 	if t.stats != nil {
-		// Note: Headers are compressed with hpack after this call returns.
-		// No WireLength field is set here.
-		outHeader := &stats.OutHeader{
-			Header:      s.header.Copy(),
-			Compression: s.sendCompress,
-		}
+		// Note: WireLength is not set in outHeader.
+		// TODO(mmukhi): Revisit this later, if needed.
+		outHeader := &stats.OutHeader{}
 		t.stats.HandleRPC(s.Context(), outHeader)
 	}
 	return nil
@@ -845,7 +840,7 @@
 	headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-status", Value: strconv.Itoa(int(st.Code()))})
 	headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-message", Value: encodeGrpcMessage(st.Message())})
 
-	if p := st.Proto(); p != nil && len(p.Details) > 0 {
+	if p := statusRawProto(st); p != nil && len(p.Details) > 0 {
 		stBytes, err := proto.Marshal(p)
 		if err != nil {
 			// TODO: return error instead, when callers are able to handle it.
@@ -876,11 +871,7 @@
 	rst := s.getState() == streamActive
 	t.finishStream(s, rst, http2.ErrCodeNo, trailingHeader, true)
 	if t.stats != nil {
-		// Note: The trailer fields are compressed with hpack after this call returns.
-		// No WireLength field is set here.
-		t.stats.HandleRPC(s.Context(), &stats.OutTrailer{
-			Trailer: s.trailer.Copy(),
-		})
+		t.stats.HandleRPC(s.Context(), &stats.OutTrailer{})
 	}
 	return nil
 }
@@ -941,35 +932,32 @@
 // after an additional duration of keepalive.Timeout.
 func (t *http2Server) keepalive() {
 	p := &ping{}
-	// True iff a ping has been sent, and no data has been received since then.
-	outstandingPing := false
-	// Amount of time remaining before which we should receive an ACK for the
-	// last sent ping.
-	kpTimeoutLeft := time.Duration(0)
-	// Records the last value of t.lastRead before we go block on the timer.
-	// This is required to check for read activity since then.
-	prevNano := time.Now().UnixNano()
-	// Initialize the different timers to their default values.
-	idleTimer := time.NewTimer(t.kp.MaxConnectionIdle)
-	ageTimer := time.NewTimer(t.kp.MaxConnectionAge)
-	kpTimer := time.NewTimer(t.kp.Time)
+	var pingSent bool
+	maxIdle := time.NewTimer(t.kp.MaxConnectionIdle)
+	maxAge := time.NewTimer(t.kp.MaxConnectionAge)
+	keepalive := time.NewTimer(t.kp.Time)
+	// NOTE: All exit paths of this function should reset their
+	// respective timers. A failure to do so will cause the
+	// following clean-up to deadlock and eventually leak.
 	defer func() {
-		// We need to drain the underlying channel in these timers after a call
-		// to Stop(), only if we are interested in resetting them. Clearly we
-		// are not interested in resetting them here.
-		idleTimer.Stop()
-		ageTimer.Stop()
-		kpTimer.Stop()
+		if !maxIdle.Stop() {
+			<-maxIdle.C
+		}
+		if !maxAge.Stop() {
+			<-maxAge.C
+		}
+		if !keepalive.Stop() {
+			<-keepalive.C
+		}
 	}()
-
 	for {
 		select {
-		case <-idleTimer.C:
+		case <-maxIdle.C:
 			t.mu.Lock()
 			idle := t.idle
 			if idle.IsZero() { // The connection is non-idle.
 				t.mu.Unlock()
-				idleTimer.Reset(t.kp.MaxConnectionIdle)
+				maxIdle.Reset(t.kp.MaxConnectionIdle)
 				continue
 			}
 			val := t.kp.MaxConnectionIdle - time.Since(idle)
@@ -978,51 +966,43 @@
 				// The connection has been idle for a duration of keepalive.MaxConnectionIdle or more.
 				// Gracefully close the connection.
 				t.drain(http2.ErrCodeNo, []byte{})
+				// Resetting the timer so that the clean-up doesn't deadlock.
+				maxIdle.Reset(infinity)
 				return
 			}
-			idleTimer.Reset(val)
-		case <-ageTimer.C:
+			maxIdle.Reset(val)
+		case <-maxAge.C:
 			t.drain(http2.ErrCodeNo, []byte{})
-			ageTimer.Reset(t.kp.MaxConnectionAgeGrace)
+			maxAge.Reset(t.kp.MaxConnectionAgeGrace)
 			select {
-			case <-ageTimer.C:
+			case <-maxAge.C:
 				// Close the connection after grace period.
 				infof("transport: closing server transport due to maximum connection age.")
 				t.Close()
+				// Resetting the timer so that the clean-up doesn't deadlock.
+				maxAge.Reset(infinity)
 			case <-t.done:
 			}
 			return
-		case <-kpTimer.C:
-			lastRead := atomic.LoadInt64(&t.lastRead)
-			if lastRead > prevNano {
-				// There has been read activity since the last time we were
-				// here. Setup the timer to fire at kp.Time seconds from
-				// lastRead time and continue.
-				outstandingPing = false
-				kpTimer.Reset(time.Duration(lastRead) + t.kp.Time - time.Duration(time.Now().UnixNano()))
-				prevNano = lastRead
+		case <-keepalive.C:
+			if atomic.CompareAndSwapUint32(&t.activity, 1, 0) {
+				pingSent = false
+				keepalive.Reset(t.kp.Time)
 				continue
 			}
-			if outstandingPing && kpTimeoutLeft <= 0 {
+			if pingSent {
 				infof("transport: closing server transport due to idleness.")
 				t.Close()
+				// Resetting the timer so that the clean-up doesn't deadlock.
+				keepalive.Reset(infinity)
 				return
 			}
-			if !outstandingPing {
-				if channelz.IsOn() {
-					atomic.AddInt64(&t.czData.kpCount, 1)
-				}
-				t.controlBuf.put(p)
-				kpTimeoutLeft = t.kp.Timeout
-				outstandingPing = true
+			pingSent = true
+			if channelz.IsOn() {
+				atomic.AddInt64(&t.czData.kpCount, 1)
 			}
-			// The amount of time to sleep here is the minimum of kp.Time and
-			// timeoutLeft. This will ensure that we wait only for kp.Time
-			// before sending out the next ping (for cases where the ping is
-			// acked).
-			sleepDuration := minTime(t.kp.Time, kpTimeoutLeft)
-			kpTimeoutLeft -= sleepDuration
-			kpTimer.Reset(sleepDuration)
+			t.controlBuf.put(p)
+			keepalive.Reset(t.kp.Timeout)
 		case <-t.done:
 			return
 		}
diff --git a/vendor/google.golang.org/grpc/internal/transport/transport.go b/vendor/google.golang.org/grpc/internal/transport/transport.go
index a30da9e..bfab940 100644
--- a/vendor/google.golang.org/grpc/internal/transport/transport.go
+++ b/vendor/google.golang.org/grpc/internal/transport/transport.go
@@ -73,11 +73,10 @@
 }
 
 // recvBuffer is an unbounded channel of recvMsg structs.
-//
-// Note: recvBuffer differs from buffer.Unbounded only in the fact that it
-// holds a channel of recvMsg structs instead of objects implementing "item"
-// interface. recvBuffer is written to much more often and using strict recvMsg
-// structs helps avoid allocation in "recvBuffer.put"
+// Note recvBuffer differs from controlBuffer only in that recvBuffer
+// holds a channel of only recvMsg structs instead of objects implementing "item" interface.
+// recvBuffer is written to much more often than
+// controlBuffer and using strict recvMsg structs helps avoid allocation in "recvBuffer.put"
 type recvBuffer struct {
 	c       chan recvMsg
 	mu      sync.Mutex
diff --git a/vendor/google.golang.org/grpc/picker_wrapper.go b/vendor/google.golang.org/grpc/picker_wrapper.go
index 0044789..45baa2a 100644
--- a/vendor/google.golang.org/grpc/picker_wrapper.go
+++ b/vendor/google.golang.org/grpc/picker_wrapper.go
@@ -20,7 +20,6 @@
 
 import (
 	"context"
-	"fmt"
 	"io"
 	"sync"
 
@@ -32,78 +31,49 @@
 	"google.golang.org/grpc/status"
 )
 
-// v2PickerWrapper wraps a balancer.Picker while providing the
-// balancer.V2Picker API.  It requires a pickerWrapper to generate errors
-// including the latest connectionError.  To be deleted when balancer.Picker is
-// updated to the balancer.V2Picker API.
-type v2PickerWrapper struct {
-	picker  balancer.Picker
-	connErr *connErr
-}
-
-func (v *v2PickerWrapper) Pick(info balancer.PickInfo) (balancer.PickResult, error) {
-	sc, done, err := v.picker.Pick(info.Ctx, info)
-	if err != nil {
-		if err == balancer.ErrTransientFailure {
-			return balancer.PickResult{}, balancer.TransientFailureError(fmt.Errorf("%v, latest connection error: %v", err, v.connErr.connectionError()))
-		}
-		return balancer.PickResult{}, err
-	}
-	return balancer.PickResult{SubConn: sc, Done: done}, nil
-}
-
 // pickerWrapper is a wrapper of balancer.Picker. It blocks on certain pick
 // actions and unblock when there's a picker update.
 type pickerWrapper struct {
 	mu         sync.Mutex
 	done       bool
 	blockingCh chan struct{}
-	picker     balancer.V2Picker
+	picker     balancer.Picker
 
-	// The latest connection error.  TODO: remove when V1 picker is deprecated;
-	// balancer should be responsible for providing the error.
-	*connErr
-}
-
-type connErr struct {
-	mu  sync.Mutex
-	err error
-}
-
-func (c *connErr) updateConnectionError(err error) {
-	c.mu.Lock()
-	c.err = err
-	c.mu.Unlock()
-}
-
-func (c *connErr) connectionError() error {
-	c.mu.Lock()
-	err := c.err
-	c.mu.Unlock()
-	return err
+	// The latest connection happened.
+	connErrMu sync.Mutex
+	connErr   error
 }
 
 func newPickerWrapper() *pickerWrapper {
-	return &pickerWrapper{blockingCh: make(chan struct{}), connErr: &connErr{}}
+	bp := &pickerWrapper{blockingCh: make(chan struct{})}
+	return bp
+}
+
+func (bp *pickerWrapper) updateConnectionError(err error) {
+	bp.connErrMu.Lock()
+	bp.connErr = err
+	bp.connErrMu.Unlock()
+}
+
+func (bp *pickerWrapper) connectionError() error {
+	bp.connErrMu.Lock()
+	err := bp.connErr
+	bp.connErrMu.Unlock()
+	return err
 }
 
 // updatePicker is called by UpdateBalancerState. It unblocks all blocked pick.
-func (pw *pickerWrapper) updatePicker(p balancer.Picker) {
-	pw.updatePickerV2(&v2PickerWrapper{picker: p, connErr: pw.connErr})
-}
-
-// updatePicker is called by UpdateBalancerState. It unblocks all blocked pick.
-func (pw *pickerWrapper) updatePickerV2(p balancer.V2Picker) {
-	pw.mu.Lock()
-	if pw.done {
-		pw.mu.Unlock()
+func (bp *pickerWrapper) updatePicker(p balancer.Picker) {
+	bp.mu.Lock()
+	if bp.done {
+		bp.mu.Unlock()
 		return
 	}
-	pw.picker = p
-	// pw.blockingCh should never be nil.
-	close(pw.blockingCh)
-	pw.blockingCh = make(chan struct{})
-	pw.mu.Unlock()
+	bp.picker = p
+	// bp.blockingCh should never be nil.
+	close(bp.blockingCh)
+	bp.blockingCh = make(chan struct{})
+	bp.mu.Unlock()
 }
 
 func doneChannelzWrapper(acw *acBalancerWrapper, done func(balancer.DoneInfo)) func(balancer.DoneInfo) {
@@ -130,85 +100,83 @@
 // - the current picker returns other errors and failfast is false.
 // - the subConn returned by the current picker is not READY
 // When one of these situations happens, pick blocks until the picker gets updated.
-func (pw *pickerWrapper) pick(ctx context.Context, failfast bool, info balancer.PickInfo) (transport.ClientTransport, func(balancer.DoneInfo), error) {
+func (bp *pickerWrapper) pick(ctx context.Context, failfast bool, opts balancer.PickOptions) (transport.ClientTransport, func(balancer.DoneInfo), error) {
 	var ch chan struct{}
 
-	var lastPickErr error
 	for {
-		pw.mu.Lock()
-		if pw.done {
-			pw.mu.Unlock()
+		bp.mu.Lock()
+		if bp.done {
+			bp.mu.Unlock()
 			return nil, nil, ErrClientConnClosing
 		}
 
-		if pw.picker == nil {
-			ch = pw.blockingCh
+		if bp.picker == nil {
+			ch = bp.blockingCh
 		}
-		if ch == pw.blockingCh {
+		if ch == bp.blockingCh {
 			// This could happen when either:
-			// - pw.picker is nil (the previous if condition), or
+			// - bp.picker is nil (the previous if condition), or
 			// - has called pick on the current picker.
-			pw.mu.Unlock()
+			bp.mu.Unlock()
 			select {
 			case <-ctx.Done():
-				var errStr string
-				if lastPickErr != nil {
-					errStr = "latest balancer error: " + lastPickErr.Error()
-				} else if connectionErr := pw.connectionError(); connectionErr != nil {
-					errStr = "latest connection error: " + connectionErr.Error()
-				} else {
-					errStr = ctx.Err().Error()
+				if connectionErr := bp.connectionError(); connectionErr != nil {
+					switch ctx.Err() {
+					case context.DeadlineExceeded:
+						return nil, nil, status.Errorf(codes.DeadlineExceeded, "latest connection error: %v", connectionErr)
+					case context.Canceled:
+						return nil, nil, status.Errorf(codes.Canceled, "latest connection error: %v", connectionErr)
+					}
 				}
-				switch ctx.Err() {
-				case context.DeadlineExceeded:
-					return nil, nil, status.Error(codes.DeadlineExceeded, errStr)
-				case context.Canceled:
-					return nil, nil, status.Error(codes.Canceled, errStr)
-				}
+				return nil, nil, ctx.Err()
 			case <-ch:
 			}
 			continue
 		}
 
-		ch = pw.blockingCh
-		p := pw.picker
-		pw.mu.Unlock()
+		ch = bp.blockingCh
+		p := bp.picker
+		bp.mu.Unlock()
 
-		pickResult, err := p.Pick(info)
+		subConn, done, err := p.Pick(ctx, opts)
 
 		if err != nil {
-			if err == balancer.ErrNoSubConnAvailable {
+			switch err {
+			case balancer.ErrNoSubConnAvailable:
 				continue
-			}
-			if tfe, ok := err.(interface{ IsTransientFailure() bool }); ok && tfe.IsTransientFailure() {
+			case balancer.ErrTransientFailure:
 				if !failfast {
-					lastPickErr = err
 					continue
 				}
-				return nil, nil, status.Error(codes.Unavailable, err.Error())
+				return nil, nil, status.Errorf(codes.Unavailable, "%v, latest connection error: %v", err, bp.connectionError())
+			case context.DeadlineExceeded:
+				return nil, nil, status.Error(codes.DeadlineExceeded, err.Error())
+			case context.Canceled:
+				return nil, nil, status.Error(codes.Canceled, err.Error())
+			default:
+				if _, ok := status.FromError(err); ok {
+					return nil, nil, err
+				}
+				// err is some other error.
+				return nil, nil, status.Error(codes.Unknown, err.Error())
 			}
-			if _, ok := status.FromError(err); ok {
-				return nil, nil, err
-			}
-			// err is some other error.
-			return nil, nil, status.Error(codes.Unknown, err.Error())
 		}
 
-		acw, ok := pickResult.SubConn.(*acBalancerWrapper)
+		acw, ok := subConn.(*acBalancerWrapper)
 		if !ok {
 			grpclog.Error("subconn returned from pick is not *acBalancerWrapper")
 			continue
 		}
 		if t, ok := acw.getAddrConn().getReadyTransport(); ok {
 			if channelz.IsOn() {
-				return t, doneChannelzWrapper(acw, pickResult.Done), nil
+				return t, doneChannelzWrapper(acw, done), nil
 			}
-			return t, pickResult.Done, nil
+			return t, done, nil
 		}
-		if pickResult.Done != nil {
+		if done != nil {
 			// Calling done with nil error, no bytes sent and no bytes received.
 			// DoneInfo with default value works.
-			pickResult.Done(balancer.DoneInfo{})
+			done(balancer.DoneInfo{})
 		}
 		grpclog.Infof("blockingPicker: the picked transport is not ready, loop back to repick")
 		// If ok == false, ac.state is not READY.
@@ -218,12 +186,12 @@
 	}
 }
 
-func (pw *pickerWrapper) close() {
-	pw.mu.Lock()
-	defer pw.mu.Unlock()
-	if pw.done {
+func (bp *pickerWrapper) close() {
+	bp.mu.Lock()
+	defer bp.mu.Unlock()
+	if bp.done {
 		return
 	}
-	pw.done = true
-	close(pw.blockingCh)
+	bp.done = true
+	close(bp.blockingCh)
 }
diff --git a/vendor/google.golang.org/grpc/pickfirst.go b/vendor/google.golang.org/grpc/pickfirst.go
index c43dac9..ed05b02 100644
--- a/vendor/google.golang.org/grpc/pickfirst.go
+++ b/vendor/google.golang.org/grpc/pickfirst.go
@@ -19,14 +19,12 @@
 package grpc
 
 import (
-	"errors"
+	"context"
 
 	"google.golang.org/grpc/balancer"
-	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/grpclog"
 	"google.golang.org/grpc/resolver"
-	"google.golang.org/grpc/status"
 )
 
 // PickFirstBalancerName is the name of the pick_first balancer.
@@ -47,67 +45,35 @@
 }
 
 type pickfirstBalancer struct {
-	state connectivity.State
-	cc    balancer.ClientConn
-	sc    balancer.SubConn
+	cc balancer.ClientConn
+	sc balancer.SubConn
 }
 
-var _ balancer.V2Balancer = &pickfirstBalancer{} // Assert we implement v2
-
 func (b *pickfirstBalancer) HandleResolvedAddrs(addrs []resolver.Address, err error) {
 	if err != nil {
-		b.ResolverError(err)
+		if grpclog.V(2) {
+			grpclog.Infof("pickfirstBalancer: HandleResolvedAddrs called with error %v", err)
+		}
 		return
 	}
-	b.UpdateClientConnState(balancer.ClientConnState{ResolverState: resolver.State{Addresses: addrs}}) // Ignore error
-}
-
-func (b *pickfirstBalancer) HandleSubConnStateChange(sc balancer.SubConn, s connectivity.State) {
-	b.UpdateSubConnState(sc, balancer.SubConnState{ConnectivityState: s})
-}
-
-func (b *pickfirstBalancer) ResolverError(err error) {
-	switch b.state {
-	case connectivity.TransientFailure, connectivity.Idle, connectivity.Connecting:
-		// Set a failing picker if we don't have a good picker.
-		b.cc.UpdateState(balancer.State{ConnectivityState: connectivity.TransientFailure,
-			Picker: &picker{err: status.Errorf(codes.Unavailable, "name resolver error: %v", err)}},
-		)
-	}
-	if grpclog.V(2) {
-		grpclog.Infof("pickfirstBalancer: ResolverError called with error %v", err)
-	}
-}
-
-func (b *pickfirstBalancer) UpdateClientConnState(cs balancer.ClientConnState) error {
-	if len(cs.ResolverState.Addresses) == 0 {
-		b.ResolverError(errors.New("produced zero addresses"))
-		return balancer.ErrBadResolverState
-	}
 	if b.sc == nil {
-		var err error
-		b.sc, err = b.cc.NewSubConn(cs.ResolverState.Addresses, balancer.NewSubConnOptions{})
+		b.sc, err = b.cc.NewSubConn(addrs, balancer.NewSubConnOptions{})
 		if err != nil {
+			//TODO(yuxuanli): why not change the cc state to Idle?
 			if grpclog.V(2) {
 				grpclog.Errorf("pickfirstBalancer: failed to NewSubConn: %v", err)
 			}
-			b.state = connectivity.TransientFailure
-			b.cc.UpdateState(balancer.State{ConnectivityState: connectivity.TransientFailure,
-				Picker: &picker{err: status.Errorf(codes.Unavailable, "error creating connection: %v", err)}},
-			)
-			return balancer.ErrBadResolverState
+			return
 		}
-		b.state = connectivity.Idle
-		b.cc.UpdateState(balancer.State{ConnectivityState: connectivity.Idle, Picker: &picker{result: balancer.PickResult{SubConn: b.sc}}})
+		b.cc.UpdateBalancerState(connectivity.Idle, &picker{sc: b.sc})
 		b.sc.Connect()
 	} else {
-		b.sc.UpdateAddresses(cs.ResolverState.Addresses)
+		b.sc.UpdateAddresses(addrs)
 		b.sc.Connect()
 	}
-	return nil
 }
 
-func (b *pickfirstBalancer) UpdateSubConnState(sc balancer.SubConn, s balancer.SubConnState) {
+func (b *pickfirstBalancer) HandleSubConnStateChange(sc balancer.SubConn, s connectivity.State) {
 	if grpclog.V(2) {
 		grpclog.Infof("pickfirstBalancer: HandleSubConnStateChange: %p, %v", sc, s)
 	}
@@ -117,28 +83,18 @@
 		}
 		return
 	}
-	b.state = s.ConnectivityState
-	if s.ConnectivityState == connectivity.Shutdown {
+	if s == connectivity.Shutdown {
 		b.sc = nil
 		return
 	}
 
-	switch s.ConnectivityState {
+	switch s {
 	case connectivity.Ready, connectivity.Idle:
-		b.cc.UpdateState(balancer.State{ConnectivityState: s.ConnectivityState, Picker: &picker{result: balancer.PickResult{SubConn: sc}}})
+		b.cc.UpdateBalancerState(s, &picker{sc: sc})
 	case connectivity.Connecting:
-		b.cc.UpdateState(balancer.State{ConnectivityState: s.ConnectivityState, Picker: &picker{err: balancer.ErrNoSubConnAvailable}})
+		b.cc.UpdateBalancerState(s, &picker{err: balancer.ErrNoSubConnAvailable})
 	case connectivity.TransientFailure:
-		err := balancer.ErrTransientFailure
-		// TODO: this can be unconditional after the V1 API is removed, as
-		// SubConnState will always contain a connection error.
-		if s.ConnectionError != nil {
-			err = balancer.TransientFailureError(s.ConnectionError)
-		}
-		b.cc.UpdateState(balancer.State{
-			ConnectivityState: s.ConnectivityState,
-			Picker:            &picker{err: err},
-		})
+		b.cc.UpdateBalancerState(s, &picker{err: balancer.ErrTransientFailure})
 	}
 }
 
@@ -146,12 +102,15 @@
 }
 
 type picker struct {
-	result balancer.PickResult
-	err    error
+	err error
+	sc  balancer.SubConn
 }
 
-func (p *picker) Pick(info balancer.PickInfo) (balancer.PickResult, error) {
-	return p.result, p.err
+func (p *picker) Pick(ctx context.Context, opts balancer.PickOptions) (balancer.SubConn, func(balancer.DoneInfo), error) {
+	if p.err != nil {
+		return nil, nil, p.err
+	}
+	return p.sc, nil, nil
 }
 
 func init() {
diff --git a/vendor/google.golang.org/grpc/reflection/grpc_reflection_v1alpha/reflection.pb.go b/vendor/google.golang.org/grpc/reflection/grpc_reflection_v1alpha/reflection.pb.go
index 89b8962..0a12ad2 100644
--- a/vendor/google.golang.org/grpc/reflection/grpc_reflection_v1alpha/reflection.pb.go
+++ b/vendor/google.golang.org/grpc/reflection/grpc_reflection_v1alpha/reflection.pb.go
@@ -635,11 +635,11 @@
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConnInterface
+var _ grpc.ClientConn
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion6
+const _ = grpc.SupportPackageIsVersion4
 
 // ServerReflectionClient is the client API for ServerReflection service.
 //
@@ -651,10 +651,10 @@
 }
 
 type serverReflectionClient struct {
-	cc grpc.ClientConnInterface
+	cc *grpc.ClientConn
 }
 
-func NewServerReflectionClient(cc grpc.ClientConnInterface) ServerReflectionClient {
+func NewServerReflectionClient(cc *grpc.ClientConn) ServerReflectionClient {
 	return &serverReflectionClient{cc}
 }
 
diff --git a/vendor/google.golang.org/grpc/resolver/resolver.go b/vendor/google.golang.org/grpc/resolver/resolver.go
index fe14b2f..4c5423b 100644
--- a/vendor/google.golang.org/grpc/resolver/resolver.go
+++ b/vendor/google.golang.org/grpc/resolver/resolver.go
@@ -24,7 +24,6 @@
 	"context"
 	"net"
 
-	"google.golang.org/grpc/attributes"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/serviceconfig"
 )
@@ -74,18 +73,12 @@
 }
 
 // AddressType indicates the address type returned by name resolution.
-//
-// Deprecated: use Attributes in Address instead.
 type AddressType uint8
 
 const (
 	// Backend indicates the address is for a backend server.
-	//
-	// Deprecated: use Attributes in Address instead.
 	Backend AddressType = iota
 	// GRPCLB indicates the address is for a grpclb load balancer.
-	//
-	// Deprecated: use Attributes in Address instead.
 	GRPCLB
 )
 
@@ -94,7 +87,8 @@
 type Address struct {
 	// Addr is the server address on which a connection will be established.
 	Addr string
-
+	// Type is the type of this address.
+	Type AddressType
 	// ServerName is the name of this address.
 	// If non-empty, the ServerName is used as the transport certification authority for
 	// the address, instead of the hostname from the Dial target string. In most cases,
@@ -107,26 +101,14 @@
 	// is insecure to populate it with data from untrusted inputs since untrusted
 	// values could be used to bypass the authority checks performed by TLS.
 	ServerName string
-
-	// Attributes contains arbitrary data about this address intended for
-	// consumption by the load balancing policy.
-	Attributes *attributes.Attributes
-
-	// Type is the type of this address.
-	//
-	// Deprecated: use Attributes instead.
-	Type AddressType
-
 	// Metadata is the information associated with Addr, which may be used
 	// to make load balancing decision.
-	//
-	// Deprecated: use Attributes instead.
 	Metadata interface{}
 }
 
-// BuildOptions includes additional information for the builder to create
+// BuildOption includes additional information for the builder to create
 // the resolver.
-type BuildOptions struct {
+type BuildOption struct {
 	// DisableServiceConfig indicates whether a resolver implementation should
 	// fetch service config data.
 	DisableServiceConfig bool
@@ -159,10 +141,6 @@
 	// config.  If it is nil, it indicates no service config is present or the
 	// resolver does not provide service configs.
 	ServiceConfig *serviceconfig.ParseResult
-
-	// Attributes contains arbitrary data about the resolver intended for
-	// consumption by the load balancing policy.
-	Attributes *attributes.Attributes
 }
 
 // ClientConn contains the callbacks for resolver to notify any updates
@@ -224,14 +202,14 @@
 	//
 	// gRPC dial calls Build synchronously, and fails if the returned error is
 	// not nil.
-	Build(target Target, cc ClientConn, opts BuildOptions) (Resolver, error)
+	Build(target Target, cc ClientConn, opts BuildOption) (Resolver, error)
 	// Scheme returns the scheme supported by this resolver.
 	// Scheme is defined at https://github.com/grpc/grpc/blob/master/doc/naming.md.
 	Scheme() string
 }
 
-// ResolveNowOptions includes additional information for ResolveNow.
-type ResolveNowOptions struct{}
+// ResolveNowOption includes additional information for ResolveNow.
+type ResolveNowOption struct{}
 
 // Resolver watches for the updates on the specified target.
 // Updates include address updates and service config updates.
@@ -240,7 +218,7 @@
 	// again. It's just a hint, resolver can ignore this if it's not necessary.
 	//
 	// It could be called multiple times concurrently.
-	ResolveNow(ResolveNowOptions)
+	ResolveNow(ResolveNowOption)
 	// Close closes the resolver.
 	Close()
 }
diff --git a/vendor/google.golang.org/grpc/resolver_conn_wrapper.go b/vendor/google.golang.org/grpc/resolver_conn_wrapper.go
index edfda86..7dcefcf 100644
--- a/vendor/google.golang.org/grpc/resolver_conn_wrapper.go
+++ b/vendor/google.golang.org/grpc/resolver_conn_wrapper.go
@@ -26,6 +26,7 @@
 
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/grpclog"
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/grpcsync"
 	"google.golang.org/grpc/resolver"
@@ -33,7 +34,7 @@
 )
 
 // ccResolverWrapper is a wrapper on top of cc for resolvers.
-// It implements resolver.ClientConn interface.
+// It implements resolver.ClientConnection interface.
 type ccResolverWrapper struct {
 	cc         *ClientConn
 	resolverMu sync.Mutex
@@ -45,9 +46,43 @@
 	polling   chan struct{}
 }
 
-// newCCResolverWrapper uses the resolver.Builder to build a Resolver and
-// returns a ccResolverWrapper object which wraps the newly built resolver.
-func newCCResolverWrapper(cc *ClientConn, rb resolver.Builder) (*ccResolverWrapper, error) {
+// split2 returns the values from strings.SplitN(s, sep, 2).
+// If sep is not found, it returns ("", "", false) instead.
+func split2(s, sep string) (string, string, bool) {
+	spl := strings.SplitN(s, sep, 2)
+	if len(spl) < 2 {
+		return "", "", false
+	}
+	return spl[0], spl[1], true
+}
+
+// parseTarget splits target into a struct containing scheme, authority and
+// endpoint.
+//
+// If target is not a valid scheme://authority/endpoint, it returns {Endpoint:
+// target}.
+func parseTarget(target string) (ret resolver.Target) {
+	var ok bool
+	ret.Scheme, ret.Endpoint, ok = split2(target, "://")
+	if !ok {
+		return resolver.Target{Endpoint: target}
+	}
+	ret.Authority, ret.Endpoint, ok = split2(ret.Endpoint, "/")
+	if !ok {
+		return resolver.Target{Endpoint: target}
+	}
+	return ret
+}
+
+// newCCResolverWrapper uses the resolver.Builder stored in the ClientConn to
+// build a Resolver and returns a ccResolverWrapper object which wraps the
+// newly built resolver.
+func newCCResolverWrapper(cc *ClientConn) (*ccResolverWrapper, error) {
+	rb := cc.dopts.resolverBuilder
+	if rb == nil {
+		return nil, fmt.Errorf("could not get resolver for scheme: %q", cc.parsedTarget.Scheme)
+	}
+
 	ccr := &ccResolverWrapper{
 		cc:   cc,
 		done: grpcsync.NewEvent(),
@@ -57,7 +92,7 @@
 	if creds := cc.dopts.copts.TransportCredentials; creds != nil {
 		credsClone = creds.Clone()
 	}
-	rbo := resolver.BuildOptions{
+	rbo := resolver.BuildOption{
 		DisableServiceConfig: cc.dopts.disableServiceConfig,
 		DialCreds:            credsClone,
 		CredsBundle:          cc.dopts.copts.CredsBundle,
@@ -70,15 +105,15 @@
 	// rb.Build-->ccr.ReportError-->ccr.poll-->ccr.resolveNow, would end up
 	// accessing ccr.resolver which is being assigned here.
 	ccr.resolverMu.Lock()
-	defer ccr.resolverMu.Unlock()
 	ccr.resolver, err = rb.Build(cc.parsedTarget, ccr, rbo)
 	if err != nil {
 		return nil, err
 	}
+	ccr.resolverMu.Unlock()
 	return ccr, nil
 }
 
-func (ccr *ccResolverWrapper) resolveNow(o resolver.ResolveNowOptions) {
+func (ccr *ccResolverWrapper) resolveNow(o resolver.ResolveNowOption) {
 	ccr.resolverMu.Lock()
 	if !ccr.done.HasFired() {
 		ccr.resolver.ResolveNow(o)
@@ -114,7 +149,7 @@
 	ccr.polling = p
 	go func() {
 		for i := 0; ; i++ {
-			ccr.resolveNow(resolver.ResolveNowOptions{})
+			ccr.resolveNow(resolver.ResolveNowOption{})
 			t := time.NewTimer(ccr.cc.dopts.resolveNowBackoff(i))
 			select {
 			case <-p:
@@ -140,7 +175,7 @@
 	if ccr.done.HasFired() {
 		return
 	}
-	channelz.Infof(ccr.cc.channelzID, "ccResolverWrapper: sending update to cc: %v", s)
+	grpclog.Infof("ccResolverWrapper: sending update to cc: %v", s)
 	if channelz.IsOn() {
 		ccr.addChannelzTraceEvent(s)
 	}
@@ -152,7 +187,13 @@
 	if ccr.done.HasFired() {
 		return
 	}
-	channelz.Warningf(ccr.cc.channelzID, "ccResolverWrapper: reporting error to cc: %v", err)
+	grpclog.Warningf("ccResolverWrapper: reporting error to cc: %v", err)
+	if channelz.IsOn() {
+		channelz.AddTraceEvent(ccr.cc.channelzID, &channelz.TraceEventDesc{
+			Desc:     fmt.Sprintf("Resolver reported error: %v", err),
+			Severity: channelz.CtWarning,
+		})
+	}
 	ccr.poll(ccr.cc.updateResolverState(resolver.State{}, err))
 }
 
@@ -161,7 +202,7 @@
 	if ccr.done.HasFired() {
 		return
 	}
-	channelz.Infof(ccr.cc.channelzID, "ccResolverWrapper: sending new addresses to cc: %v", addrs)
+	grpclog.Infof("ccResolverWrapper: sending new addresses to cc: %v", addrs)
 	if channelz.IsOn() {
 		ccr.addChannelzTraceEvent(resolver.State{Addresses: addrs, ServiceConfig: ccr.curState.ServiceConfig})
 	}
@@ -175,14 +216,16 @@
 	if ccr.done.HasFired() {
 		return
 	}
-	channelz.Infof(ccr.cc.channelzID, "ccResolverWrapper: got new service config: %v", sc)
-	if ccr.cc.dopts.disableServiceConfig {
-		channelz.Info(ccr.cc.channelzID, "Service config lookups disabled; ignoring config")
-		return
-	}
+	grpclog.Infof("ccResolverWrapper: got new service config: %v", sc)
 	scpr := parseServiceConfig(sc)
 	if scpr.Err != nil {
-		channelz.Warningf(ccr.cc.channelzID, "ccResolverWrapper: error parsing service config: %v", scpr.Err)
+		grpclog.Warningf("ccResolverWrapper: error parsing service config: %v", scpr.Err)
+		if channelz.IsOn() {
+			channelz.AddTraceEvent(ccr.cc.channelzID, &channelz.TraceEventDesc{
+				Desc:     fmt.Sprintf("Error parsing service config: %v", scpr.Err),
+				Severity: channelz.CtWarning,
+			})
+		}
 		ccr.poll(balancer.ErrBadResolverState)
 		return
 	}
@@ -215,7 +258,7 @@
 	} else if len(ccr.curState.Addresses) == 0 && len(s.Addresses) > 0 {
 		updates = append(updates, "resolver returned new addresses")
 	}
-	channelz.AddTraceEvent(ccr.cc.channelzID, 0, &channelz.TraceEventDesc{
+	channelz.AddTraceEvent(ccr.cc.channelzID, &channelz.TraceEventDesc{
 		Desc:     fmt.Sprintf("Resolver state updated: %+v (%v)", s, strings.Join(updates, "; ")),
 		Severity: channelz.CtINFO,
 	})
diff --git a/vendor/google.golang.org/grpc/rpc_util.go b/vendor/google.golang.org/grpc/rpc_util.go
index cf9dbe7..edaba79 100644
--- a/vendor/google.golang.org/grpc/rpc_util.go
+++ b/vendor/google.golang.org/grpc/rpc_util.go
@@ -287,14 +287,13 @@
 }
 func (o FailFastCallOption) after(c *callInfo) {}
 
-// MaxCallRecvMsgSize returns a CallOption which sets the maximum message size
-// in bytes the client can receive.
-func MaxCallRecvMsgSize(bytes int) CallOption {
-	return MaxRecvMsgSizeCallOption{MaxRecvMsgSize: bytes}
+// MaxCallRecvMsgSize returns a CallOption which sets the maximum message size the client can receive.
+func MaxCallRecvMsgSize(s int) CallOption {
+	return MaxRecvMsgSizeCallOption{MaxRecvMsgSize: s}
 }
 
 // MaxRecvMsgSizeCallOption is a CallOption that indicates the maximum message
-// size in bytes the client can receive.
+// size the client can receive.
 // This is an EXPERIMENTAL API.
 type MaxRecvMsgSizeCallOption struct {
 	MaxRecvMsgSize int
@@ -306,14 +305,13 @@
 }
 func (o MaxRecvMsgSizeCallOption) after(c *callInfo) {}
 
-// MaxCallSendMsgSize returns a CallOption which sets the maximum message size
-// in bytes the client can send.
-func MaxCallSendMsgSize(bytes int) CallOption {
-	return MaxSendMsgSizeCallOption{MaxSendMsgSize: bytes}
+// MaxCallSendMsgSize returns a CallOption which sets the maximum message size the client can send.
+func MaxCallSendMsgSize(s int) CallOption {
+	return MaxSendMsgSizeCallOption{MaxSendMsgSize: s}
 }
 
 // MaxSendMsgSizeCallOption is a CallOption that indicates the maximum message
-// size in bytes the client can send.
+// size the client can send.
 // This is an EXPERIMENTAL API.
 type MaxSendMsgSizeCallOption struct {
 	MaxSendMsgSize int
@@ -873,7 +871,7 @@
 
 // The SupportPackageIsVersion variables are referenced from generated protocol
 // buffer files to ensure compatibility with the gRPC version used.  The latest
-// support package version is 6.
+// support package version is 5.
 //
 // Older versions are kept for compatibility. They may be removed if
 // compatibility cannot be maintained.
@@ -883,7 +881,6 @@
 	SupportPackageIsVersion3 = true
 	SupportPackageIsVersion4 = true
 	SupportPackageIsVersion5 = true
-	SupportPackageIsVersion6 = true
 )
 
 const grpcUA = "grpc-go/" + Version
diff --git a/vendor/google.golang.org/grpc/server.go b/vendor/google.golang.org/grpc/server.go
index edfcdca..e54083d 100644
--- a/vendor/google.golang.org/grpc/server.go
+++ b/vendor/google.golang.org/grpc/server.go
@@ -116,8 +116,6 @@
 	dc                    Decompressor
 	unaryInt              UnaryServerInterceptor
 	streamInt             StreamServerInterceptor
-	chainUnaryInts        []UnaryServerInterceptor
-	chainStreamInts       []StreamServerInterceptor
 	inTapHandle           tap.ServerInHandle
 	statsHandler          stats.Handler
 	maxConcurrentStreams  uint32
@@ -313,16 +311,6 @@
 	})
 }
 
-// ChainUnaryInterceptor returns a ServerOption that specifies the chained interceptor
-// for unary RPCs. The first interceptor will be the outer most,
-// while the last interceptor will be the inner most wrapper around the real call.
-// All unary interceptors added by this method will be chained.
-func ChainUnaryInterceptor(interceptors ...UnaryServerInterceptor) ServerOption {
-	return newFuncServerOption(func(o *serverOptions) {
-		o.chainUnaryInts = append(o.chainUnaryInts, interceptors...)
-	})
-}
-
 // StreamInterceptor returns a ServerOption that sets the StreamServerInterceptor for the
 // server. Only one stream interceptor can be installed.
 func StreamInterceptor(i StreamServerInterceptor) ServerOption {
@@ -334,16 +322,6 @@
 	})
 }
 
-// ChainStreamInterceptor returns a ServerOption that specifies the chained interceptor
-// for stream RPCs. The first interceptor will be the outer most,
-// while the last interceptor will be the inner most wrapper around the real call.
-// All stream interceptors added by this method will be chained.
-func ChainStreamInterceptor(interceptors ...StreamServerInterceptor) ServerOption {
-	return newFuncServerOption(func(o *serverOptions) {
-		o.chainStreamInts = append(o.chainStreamInts, interceptors...)
-	})
-}
-
 // InTapHandle returns a ServerOption that sets the tap handle for all the server
 // transport to be created. Only one can be installed.
 func InTapHandle(h tap.ServerInHandle) ServerOption {
@@ -366,8 +344,8 @@
 // unknown service handler. The provided method is a bidi-streaming RPC service
 // handler that will be invoked instead of returning the "unimplemented" gRPC
 // error whenever a request is received for an unregistered service or method.
-// The handling function and stream interceptor (if set) have full access to
-// the ServerStream, including its Context.
+// The handling function has full access to the Context of the request and the
+// stream, and the invocation bypasses interceptors.
 func UnknownServiceHandler(streamHandler StreamHandler) ServerOption {
 	return newFuncServerOption(func(o *serverOptions) {
 		o.unknownStreamDesc = &StreamDesc{
@@ -426,8 +404,6 @@
 		done:   grpcsync.NewEvent(),
 		czData: new(channelzData),
 	}
-	chainUnaryServerInterceptors(s)
-	chainStreamServerInterceptors(s)
 	s.cv = sync.NewCond(&s.mu)
 	if EnableTracing {
 		_, file, line, _ := runtime.Caller(1)
@@ -682,7 +658,7 @@
 			s.mu.Lock()
 			s.errorf("ServerHandshake(%q) failed: %v", rawConn.RemoteAddr(), err)
 			s.mu.Unlock()
-			channelz.Warningf(s.channelzID, "grpc: Server.Serve failed to complete security handshake from %q: %v", rawConn.RemoteAddr(), err)
+			grpclog.Warningf("grpc: Server.Serve failed to complete security handshake from %q: %v", rawConn.RemoteAddr(), err)
 			rawConn.Close()
 		}
 		rawConn.SetDeadline(time.Time{})
@@ -729,7 +705,7 @@
 		s.errorf("NewServerTransport(%q) failed: %v", c.RemoteAddr(), err)
 		s.mu.Unlock()
 		c.Close()
-		channelz.Warning(s.channelzID, "grpc: Server.Serve failed to create ServerTransport: ", err)
+		grpclog.Warningln("grpc: Server.Serve failed to create ServerTransport: ", err)
 		return nil
 	}
 
@@ -868,12 +844,12 @@
 func (s *Server) sendResponse(t transport.ServerTransport, stream *transport.Stream, msg interface{}, cp Compressor, opts *transport.Options, comp encoding.Compressor) error {
 	data, err := encode(s.getCodec(stream.ContentSubtype()), msg)
 	if err != nil {
-		channelz.Error(s.channelzID, "grpc: server failed to encode response: ", err)
+		grpclog.Errorln("grpc: server failed to encode response: ", err)
 		return err
 	}
 	compData, err := compress(data, cp, comp)
 	if err != nil {
-		channelz.Error(s.channelzID, "grpc: server failed to compress response: ", err)
+		grpclog.Errorln("grpc: server failed to compress response: ", err)
 		return err
 	}
 	hdr, payload := msgHeader(data, compData)
@@ -888,93 +864,42 @@
 	return err
 }
 
-// chainUnaryServerInterceptors chains all unary server interceptors into one.
-func chainUnaryServerInterceptors(s *Server) {
-	// Prepend opts.unaryInt to the chaining interceptors if it exists, since unaryInt will
-	// be executed before any other chained interceptors.
-	interceptors := s.opts.chainUnaryInts
-	if s.opts.unaryInt != nil {
-		interceptors = append([]UnaryServerInterceptor{s.opts.unaryInt}, s.opts.chainUnaryInts...)
-	}
-
-	var chainedInt UnaryServerInterceptor
-	if len(interceptors) == 0 {
-		chainedInt = nil
-	} else if len(interceptors) == 1 {
-		chainedInt = interceptors[0]
-	} else {
-		chainedInt = func(ctx context.Context, req interface{}, info *UnaryServerInfo, handler UnaryHandler) (interface{}, error) {
-			return interceptors[0](ctx, req, info, getChainUnaryHandler(interceptors, 0, info, handler))
-		}
-	}
-
-	s.opts.unaryInt = chainedInt
-}
-
-// getChainUnaryHandler recursively generate the chained UnaryHandler
-func getChainUnaryHandler(interceptors []UnaryServerInterceptor, curr int, info *UnaryServerInfo, finalHandler UnaryHandler) UnaryHandler {
-	if curr == len(interceptors)-1 {
-		return finalHandler
-	}
-
-	return func(ctx context.Context, req interface{}) (interface{}, error) {
-		return interceptors[curr+1](ctx, req, info, getChainUnaryHandler(interceptors, curr+1, info, finalHandler))
-	}
-}
-
 func (s *Server) processUnaryRPC(t transport.ServerTransport, stream *transport.Stream, srv *service, md *MethodDesc, trInfo *traceInfo) (err error) {
-	sh := s.opts.statsHandler
-	if sh != nil || trInfo != nil || channelz.IsOn() {
-		if channelz.IsOn() {
-			s.incrCallsStarted()
-		}
-		var statsBegin *stats.Begin
-		if sh != nil {
-			beginTime := time.Now()
-			statsBegin = &stats.Begin{
-				BeginTime: beginTime,
-			}
-			sh.HandleRPC(stream.Context(), statsBegin)
-		}
-		if trInfo != nil {
-			trInfo.tr.LazyLog(&trInfo.firstLine, false)
-		}
-		// The deferred error handling for tracing, stats handler and channelz are
-		// combined into one function to reduce stack usage -- a defer takes ~56-64
-		// bytes on the stack, so overflowing the stack will require a stack
-		// re-allocation, which is expensive.
-		//
-		// To maintain behavior similar to separate deferred statements, statements
-		// should be executed in the reverse order. That is, tracing first, stats
-		// handler second, and channelz last. Note that panics *within* defers will
-		// lead to different behavior, but that's an acceptable compromise; that
-		// would be undefined behavior territory anyway.
+	if channelz.IsOn() {
+		s.incrCallsStarted()
 		defer func() {
-			if trInfo != nil {
-				if err != nil && err != io.EOF {
-					trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
-					trInfo.tr.SetError()
-				}
-				trInfo.tr.Finish()
+			if err != nil && err != io.EOF {
+				s.incrCallsFailed()
+			} else {
+				s.incrCallsSucceeded()
 			}
-
-			if sh != nil {
-				end := &stats.End{
-					BeginTime: statsBegin.BeginTime,
-					EndTime:   time.Now(),
-				}
-				if err != nil && err != io.EOF {
-					end.Error = toRPCErr(err)
-				}
-				sh.HandleRPC(stream.Context(), end)
+		}()
+	}
+	sh := s.opts.statsHandler
+	if sh != nil {
+		beginTime := time.Now()
+		begin := &stats.Begin{
+			BeginTime: beginTime,
+		}
+		sh.HandleRPC(stream.Context(), begin)
+		defer func() {
+			end := &stats.End{
+				BeginTime: beginTime,
+				EndTime:   time.Now(),
 			}
-
-			if channelz.IsOn() {
-				if err != nil && err != io.EOF {
-					s.incrCallsFailed()
-				} else {
-					s.incrCallsSucceeded()
-				}
+			if err != nil && err != io.EOF {
+				end.Error = toRPCErr(err)
+			}
+			sh.HandleRPC(stream.Context(), end)
+		}()
+	}
+	if trInfo != nil {
+		defer trInfo.tr.Finish()
+		trInfo.tr.LazyLog(&trInfo.firstLine, false)
+		defer func() {
+			if err != nil && err != io.EOF {
+				trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
+				trInfo.tr.SetError()
 			}
 		}()
 	}
@@ -1047,7 +972,7 @@
 	if err != nil {
 		if st, ok := status.FromError(err); ok {
 			if e := t.WriteStatus(stream, st); e != nil {
-				channelz.Warningf(s.channelzID, "grpc: Server.processUnaryRPC failed to write status %v", e)
+				grpclog.Warningf("grpc: Server.processUnaryRPC failed to write status %v", e)
 			}
 		}
 		return err
@@ -1092,7 +1017,7 @@
 			trInfo.tr.SetError()
 		}
 		if e := t.WriteStatus(stream, appStatus); e != nil {
-			channelz.Warningf(s.channelzID, "grpc: Server.processUnaryRPC failed to write status: %v", e)
+			grpclog.Warningf("grpc: Server.processUnaryRPC failed to write status: %v", e)
 		}
 		if binlog != nil {
 			if h, _ := stream.Header(); h.Len() > 0 {
@@ -1119,9 +1044,9 @@
 			// The entire stream is done (for unary RPC only).
 			return err
 		}
-		if sts, ok := status.FromError(err); ok {
-			if e := t.WriteStatus(stream, sts); e != nil {
-				channelz.Warningf(s.channelzID, "grpc: Server.processUnaryRPC failed to write status: %v", e)
+		if s, ok := status.FromError(err); ok {
+			if e := t.WriteStatus(stream, s); e != nil {
+				grpclog.Warningf("grpc: Server.processUnaryRPC failed to write status: %v", e)
 			}
 		} else {
 			switch st := err.(type) {
@@ -1171,52 +1096,34 @@
 	return err
 }
 
-// chainStreamServerInterceptors chains all stream server interceptors into one.
-func chainStreamServerInterceptors(s *Server) {
-	// Prepend opts.streamInt to the chaining interceptors if it exists, since streamInt will
-	// be executed before any other chained interceptors.
-	interceptors := s.opts.chainStreamInts
-	if s.opts.streamInt != nil {
-		interceptors = append([]StreamServerInterceptor{s.opts.streamInt}, s.opts.chainStreamInts...)
-	}
-
-	var chainedInt StreamServerInterceptor
-	if len(interceptors) == 0 {
-		chainedInt = nil
-	} else if len(interceptors) == 1 {
-		chainedInt = interceptors[0]
-	} else {
-		chainedInt = func(srv interface{}, ss ServerStream, info *StreamServerInfo, handler StreamHandler) error {
-			return interceptors[0](srv, ss, info, getChainStreamHandler(interceptors, 0, info, handler))
-		}
-	}
-
-	s.opts.streamInt = chainedInt
-}
-
-// getChainStreamHandler recursively generate the chained StreamHandler
-func getChainStreamHandler(interceptors []StreamServerInterceptor, curr int, info *StreamServerInfo, finalHandler StreamHandler) StreamHandler {
-	if curr == len(interceptors)-1 {
-		return finalHandler
-	}
-
-	return func(srv interface{}, ss ServerStream) error {
-		return interceptors[curr+1](srv, ss, info, getChainStreamHandler(interceptors, curr+1, info, finalHandler))
-	}
-}
-
 func (s *Server) processStreamingRPC(t transport.ServerTransport, stream *transport.Stream, srv *service, sd *StreamDesc, trInfo *traceInfo) (err error) {
 	if channelz.IsOn() {
 		s.incrCallsStarted()
+		defer func() {
+			if err != nil && err != io.EOF {
+				s.incrCallsFailed()
+			} else {
+				s.incrCallsSucceeded()
+			}
+		}()
 	}
 	sh := s.opts.statsHandler
-	var statsBegin *stats.Begin
 	if sh != nil {
 		beginTime := time.Now()
-		statsBegin = &stats.Begin{
+		begin := &stats.Begin{
 			BeginTime: beginTime,
 		}
-		sh.HandleRPC(stream.Context(), statsBegin)
+		sh.HandleRPC(stream.Context(), begin)
+		defer func() {
+			end := &stats.End{
+				BeginTime: beginTime,
+				EndTime:   time.Now(),
+			}
+			if err != nil && err != io.EOF {
+				end.Error = toRPCErr(err)
+			}
+			sh.HandleRPC(stream.Context(), end)
+		}()
 	}
 	ctx := NewContextWithServerTransportStream(stream.Context(), stream)
 	ss := &serverStream{
@@ -1231,41 +1138,6 @@
 		statsHandler:          sh,
 	}
 
-	if sh != nil || trInfo != nil || channelz.IsOn() {
-		// See comment in processUnaryRPC on defers.
-		defer func() {
-			if trInfo != nil {
-				ss.mu.Lock()
-				if err != nil && err != io.EOF {
-					ss.trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
-					ss.trInfo.tr.SetError()
-				}
-				ss.trInfo.tr.Finish()
-				ss.trInfo.tr = nil
-				ss.mu.Unlock()
-			}
-
-			if sh != nil {
-				end := &stats.End{
-					BeginTime: statsBegin.BeginTime,
-					EndTime:   time.Now(),
-				}
-				if err != nil && err != io.EOF {
-					end.Error = toRPCErr(err)
-				}
-				sh.HandleRPC(stream.Context(), end)
-			}
-
-			if channelz.IsOn() {
-				if err != nil && err != io.EOF {
-					s.incrCallsFailed()
-				} else {
-					s.incrCallsSucceeded()
-				}
-			}
-		}()
-	}
-
 	ss.binlog = binarylog.GetMethodLogger(stream.Method())
 	if ss.binlog != nil {
 		md, _ := metadata.FromIncomingContext(ctx)
@@ -1319,6 +1191,16 @@
 
 	if trInfo != nil {
 		trInfo.tr.LazyLog(&trInfo.firstLine, false)
+		defer func() {
+			ss.mu.Lock()
+			if err != nil && err != io.EOF {
+				ss.trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
+				ss.trInfo.tr.SetError()
+			}
+			ss.trInfo.tr.Finish()
+			ss.trInfo.tr = nil
+			ss.mu.Unlock()
+		}()
 	}
 	var appErr error
 	var server interface{}
@@ -1389,7 +1271,7 @@
 				trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
 				trInfo.tr.SetError()
 			}
-			channelz.Warningf(s.channelzID, "grpc: Server.handleStream failed to write status: %v", err)
+			grpclog.Warningf("grpc: Server.handleStream failed to write status: %v", err)
 		}
 		if trInfo != nil {
 			trInfo.tr.Finish()
@@ -1430,7 +1312,7 @@
 			trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
 			trInfo.tr.SetError()
 		}
-		channelz.Warningf(s.channelzID, "grpc: Server.handleStream failed to write status: %v", err)
+		grpclog.Warningf("grpc: Server.handleStream failed to write status: %v", err)
 	}
 	if trInfo != nil {
 		trInfo.tr.Finish()
diff --git a/vendor/google.golang.org/grpc/service_config.go b/vendor/google.golang.org/grpc/service_config.go
index 5a80a57..4f8836d 100644
--- a/vendor/google.golang.org/grpc/service_config.go
+++ b/vendor/google.golang.org/grpc/service_config.go
@@ -136,9 +136,9 @@
 	maxAttempts int
 
 	// Exponential backoff parameters. The initial retry attempt will occur at
-	// random(0, initialBackoff). In general, the nth attempt will occur at
+	// random(0, initialBackoffMS). In general, the nth attempt will occur at
 	// random(0,
-	//   min(initialBackoff*backoffMultiplier**(n-1), maxBackoff)).
+	//   min(initialBackoffMS*backoffMultiplier**(n-1), maxBackoffMS)).
 	//
 	// These fields are required and must be greater than zero.
 	initialBackoff    time.Duration
diff --git a/vendor/google.golang.org/grpc/stats/stats.go b/vendor/google.golang.org/grpc/stats/stats.go
index a7970c7..f3f593c 100644
--- a/vendor/google.golang.org/grpc/stats/stats.go
+++ b/vendor/google.golang.org/grpc/stats/stats.go
@@ -81,10 +81,6 @@
 	Client bool
 	// WireLength is the wire length of header.
 	WireLength int
-	// Compression is the compression algorithm used for the RPC.
-	Compression string
-	// Header contains the header metadata received.
-	Header metadata.MD
 
 	// The following fields are valid only if Client is false.
 	// FullMethod is the full RPC method string, i.e., /package.service/method.
@@ -93,6 +89,8 @@
 	RemoteAddr net.Addr
 	// LocalAddr is the local address of the corresponding connection.
 	LocalAddr net.Addr
+	// Compression is the compression algorithm used for the RPC.
+	Compression string
 }
 
 // IsClient indicates if the stats information is from client side.
@@ -106,9 +104,6 @@
 	Client bool
 	// WireLength is the wire length of trailer.
 	WireLength int
-	// Trailer contains the trailer metadata received from the server. This
-	// field is only valid if this InTrailer is from the client side.
-	Trailer metadata.MD
 }
 
 // IsClient indicates if the stats information is from client side.
@@ -141,10 +136,6 @@
 type OutHeader struct {
 	// Client is true if this OutHeader is from client side.
 	Client bool
-	// Compression is the compression algorithm used for the RPC.
-	Compression string
-	// Header contains the header metadata sent.
-	Header metadata.MD
 
 	// The following fields are valid only if Client is true.
 	// FullMethod is the full RPC method string, i.e., /package.service/method.
@@ -153,6 +144,8 @@
 	RemoteAddr net.Addr
 	// LocalAddr is the local address of the corresponding connection.
 	LocalAddr net.Addr
+	// Compression is the compression algorithm used for the RPC.
+	Compression string
 }
 
 // IsClient indicates if this stats information is from client side.
@@ -165,13 +158,7 @@
 	// Client is true if this OutTrailer is from client side.
 	Client bool
 	// WireLength is the wire length of trailer.
-	//
-	// Deprecated: This field is never set. The length is not known when this message is
-	// emitted because the trailer fields are compressed with hpack after that.
 	WireLength int
-	// Trailer contains the trailer metadata sent to the client. This
-	// field is only valid if this OutTrailer is from the server side.
-	Trailer metadata.MD
 }
 
 // IsClient indicates if this stats information is from client side.
@@ -189,7 +176,6 @@
 	EndTime time.Time
 	// Trailer contains the trailer metadata received from the server. This
 	// field is only valid if this End is from the client side.
-	// Deprecated: use Trailer in InTrailer instead.
 	Trailer metadata.MD
 	// Error is the error the RPC ended with. It is an error generated from
 	// status.Status and can be converted back to status.Status using
diff --git a/vendor/google.golang.org/grpc/status/status.go b/vendor/google.golang.org/grpc/status/status.go
index 01e182c..a1348e9 100644
--- a/vendor/google.golang.org/grpc/status/status.go
+++ b/vendor/google.golang.org/grpc/status/status.go
@@ -29,23 +29,88 @@
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes"
 	spb "google.golang.org/genproto/googleapis/rpc/status"
-
 	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/internal/status"
+	"google.golang.org/grpc/internal"
 )
 
-// Status references google.golang.org/grpc/internal/status. It represents an
-// RPC status code, message, and details.  It is immutable and should be
-// created with New, Newf, or FromProto.
-// https://godoc.org/google.golang.org/grpc/internal/status
-type Status = status.Status
+func init() {
+	internal.StatusRawProto = statusRawProto
+}
+
+func statusRawProto(s *Status) *spb.Status { return s.s }
+
+// statusError is an alias of a status proto.  It implements error and Status,
+// and a nil statusError should never be returned by this package.
+type statusError spb.Status
+
+func (se *statusError) Error() string {
+	p := (*spb.Status)(se)
+	return fmt.Sprintf("rpc error: code = %s desc = %s", codes.Code(p.GetCode()), p.GetMessage())
+}
+
+func (se *statusError) GRPCStatus() *Status {
+	return &Status{s: (*spb.Status)(se)}
+}
+
+// Is implements future error.Is functionality.
+// A statusError is equivalent if the code and message are identical.
+func (se *statusError) Is(target error) bool {
+	tse, ok := target.(*statusError)
+	if !ok {
+		return false
+	}
+
+	return proto.Equal((*spb.Status)(se), (*spb.Status)(tse))
+}
+
+// Status represents an RPC status code, message, and details.  It is immutable
+// and should be created with New, Newf, or FromProto.
+type Status struct {
+	s *spb.Status
+}
+
+// Code returns the status code contained in s.
+func (s *Status) Code() codes.Code {
+	if s == nil || s.s == nil {
+		return codes.OK
+	}
+	return codes.Code(s.s.Code)
+}
+
+// Message returns the message contained in s.
+func (s *Status) Message() string {
+	if s == nil || s.s == nil {
+		return ""
+	}
+	return s.s.Message
+}
+
+// Proto returns s's status as an spb.Status proto message.
+func (s *Status) Proto() *spb.Status {
+	if s == nil {
+		return nil
+	}
+	return proto.Clone(s.s).(*spb.Status)
+}
+
+// Err returns an immutable error representing s; returns nil if s.Code() is
+// OK.
+func (s *Status) Err() error {
+	if s.Code() == codes.OK {
+		return nil
+	}
+	return (*statusError)(s.s)
+}
 
 // New returns a Status representing c and msg.
 func New(c codes.Code, msg string) *Status {
-	return status.New(c, msg)
+	return &Status{s: &spb.Status{Code: int32(c), Message: msg}}
 }
 
 // Newf returns New(c, fmt.Sprintf(format, a...)).
@@ -70,7 +135,7 @@
 
 // FromProto returns a Status representing s.
 func FromProto(s *spb.Status) *Status {
-	return status.FromProto(s)
+	return &Status{s: proto.Clone(s).(*spb.Status)}
 }
 
 // FromError returns a Status representing err if it was produced from this
@@ -95,6 +160,42 @@
 	return s
 }
 
+// WithDetails returns a new status with the provided details messages appended to the status.
+// If any errors are encountered, it returns nil and the first error encountered.
+func (s *Status) WithDetails(details ...proto.Message) (*Status, error) {
+	if s.Code() == codes.OK {
+		return nil, errors.New("no error details for status with code OK")
+	}
+	// s.Code() != OK implies that s.Proto() != nil.
+	p := s.Proto()
+	for _, detail := range details {
+		any, err := ptypes.MarshalAny(detail)
+		if err != nil {
+			return nil, err
+		}
+		p.Details = append(p.Details, any)
+	}
+	return &Status{s: p}, nil
+}
+
+// Details returns a slice of details messages attached to the status.
+// If a detail cannot be decoded, the error is returned in place of the detail.
+func (s *Status) Details() []interface{} {
+	if s == nil || s.s == nil {
+		return nil
+	}
+	details := make([]interface{}, 0, len(s.s.Details))
+	for _, any := range s.s.Details {
+		detail := &ptypes.DynamicAny{}
+		if err := ptypes.UnmarshalAny(any, detail); err != nil {
+			details = append(details, err)
+			continue
+		}
+		details = append(details, detail.Message)
+	}
+	return details
+}
+
 // Code returns the Code of the error if it is a Status error, codes.OK if err
 // is nil, or codes.Unknown otherwise.
 func Code(err error) codes.Code {
diff --git a/vendor/google.golang.org/grpc/stream.go b/vendor/google.golang.org/grpc/stream.go
index 934ef68..bb99940 100644
--- a/vendor/google.golang.org/grpc/stream.go
+++ b/vendor/google.golang.org/grpc/stream.go
@@ -31,6 +31,7 @@
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/encoding"
+	"google.golang.org/grpc/grpclog"
 	"google.golang.org/grpc/internal/balancerload"
 	"google.golang.org/grpc/internal/binarylog"
 	"google.golang.org/grpc/internal/channelz"
@@ -497,13 +498,13 @@
 		if len(sps) == 1 {
 			var e error
 			if pushback, e = strconv.Atoi(sps[0]); e != nil || pushback < 0 {
-				channelz.Infof(cs.cc.channelzID, "Server retry pushback specified to abort (%q).", sps[0])
+				grpclog.Infof("Server retry pushback specified to abort (%q).", sps[0])
 				cs.retryThrottler.throttle() // This counts as a failure for throttling.
 				return err
 			}
 			hasPushback = true
 		} else if len(sps) > 1 {
-			channelz.Warningf(cs.cc.channelzID, "Server retry pushback specified multiple values (%q); not retrying.", sps)
+			grpclog.Warningf("Server retry pushback specified multiple values (%q); not retrying.", sps)
 			cs.retryThrottler.throttle() // This counts as a failure for throttling.
 			return err
 		}
diff --git a/vendor/google.golang.org/grpc/trace.go b/vendor/google.golang.org/grpc/trace.go
index 07a2d26..0a57b99 100644
--- a/vendor/google.golang.org/grpc/trace.go
+++ b/vendor/google.golang.org/grpc/trace.go
@@ -41,6 +41,9 @@
 	if i := strings.Index(m, "/"); i >= 0 {
 		m = m[:i] // remove everything from second slash
 	}
+	if i := strings.LastIndex(m, "."); i >= 0 {
+		m = m[i+1:] // cut down to last dotted component
+	}
 	return m
 }
 
diff --git a/vendor/google.golang.org/grpc/version.go b/vendor/google.golang.org/grpc/version.go
index ca5d55f..40af096 100644
--- a/vendor/google.golang.org/grpc/version.go
+++ b/vendor/google.golang.org/grpc/version.go
@@ -19,4 +19,4 @@
 package grpc
 
 // Version is the current grpc version.
-const Version = "1.29.1"
+const Version = "1.25.1"
diff --git a/vendor/google.golang.org/grpc/vet.sh b/vendor/google.golang.org/grpc/vet.sh
index e12024f..f324be5 100644
--- a/vendor/google.golang.org/grpc/vet.sh
+++ b/vendor/google.golang.org/grpc/vet.sh
@@ -1,22 +1,20 @@
 #!/bin/bash
 
+if [[ `uname -a` = *"Darwin"* ]]; then
+  echo "It seems you are running on Mac. This script does not work on Mac. See https://github.com/grpc/grpc-go/issues/2047"
+  exit 1
+fi
+
 set -ex  # Exit on error; debugging enabled.
 set -o pipefail  # Fail a pipe if any sub-command fails.
 
-# not makes sure the command passed to it does not exit with a return code of 0.
-not() {
-  # This is required instead of the earlier (! $COMMAND) because subshells and
-  # pipefail don't work the same on Darwin as in Linux.
-  ! "$@"
-}
-
 die() {
   echo "$@" >&2
   exit 1
 }
 
 fail_on_output() {
-  tee /dev/stderr | not read
+  tee /dev/stderr | (! read)
 }
 
 # Check to make sure it's safe to modify the user's git repo.
@@ -62,7 +60,7 @@
       unzip ${PROTOC_FILENAME}
       bin/protoc --version
       popd
-    elif not which protoc > /dev/null; then
+    elif ! which protoc > /dev/null; then
       die "Please install protoc into your path"
     fi
   fi
@@ -72,21 +70,21 @@
 fi
 
 # - Ensure all source files contain a copyright message.
-not git grep -L "\(Copyright [0-9]\{4,\} gRPC authors\)\|DO NOT EDIT" -- '*.go'
+(! git grep -L "\(Copyright [0-9]\{4,\} gRPC authors\)\|DO NOT EDIT" -- '*.go')
 
 # - Make sure all tests in grpc and grpc/test use leakcheck via Teardown.
-not grep 'func Test[^(]' *_test.go
-not grep 'func Test[^(]' test/*.go
+(! grep 'func Test[^(]' *_test.go)
+(! grep 'func Test[^(]' test/*.go)
 
 # - Do not import x/net/context.
-not git grep -l 'x/net/context' -- "*.go"
+(! git grep -l 'x/net/context' -- "*.go")
 
 # - Do not import math/rand for real library code.  Use internal/grpcrand for
 #   thread safety.
-git grep -l '"math/rand"' -- "*.go" 2>&1 | not grep -v '^examples\|^stress\|grpcrand\|^benchmark\|wrr_test'
+git grep -l '"math/rand"' -- "*.go" 2>&1 | (! grep -v '^examples\|^stress\|grpcrand\|wrr_test')
 
 # - Ensure all ptypes proto packages are renamed when importing.
-not git grep "\(import \|^\s*\)\"github.com/golang/protobuf/ptypes/" -- "*.go"
+(! git grep "\(import \|^\s*\)\"github.com/golang/protobuf/ptypes/" -- "*.go")
 
 # - Check imports that are illegal in appengine (until Go 1.11).
 # TODO: Remove when we drop Go 1.10 support
@@ -94,11 +92,9 @@
 
 # - gofmt, goimports, golint (with exceptions for generated code), go vet.
 gofmt -s -d -l . 2>&1 | fail_on_output
-goimports -l . 2>&1 | not grep -vE "(_mock|\.pb)\.go"
-golint ./... 2>&1 | not grep -vE "(_mock|\.pb)\.go:"
-go vet -all ./...
-
-misspell -error .
+goimports -l . 2>&1 | (! grep -vE "(_mock|\.pb)\.go") | fail_on_output
+golint ./... 2>&1 | (! grep -vE "(_mock|\.pb)\.go:")
+go vet -all .
 
 # - Check that generated proto files are up to date.
 if [[ -z "${VET_SKIP_PROTO}" ]]; then
@@ -115,49 +111,32 @@
 fi
 
 # - Collection of static analysis checks
-#
-# TODO(dfawley): don't use deprecated functions in examples or first-party
-# plugins.
-SC_OUT="$(mktemp)"
-staticcheck -go 1.9 -checks 'inherit,-ST1015' ./... > "${SC_OUT}" || true
-# Error if anything other than deprecation warnings are printed.
-not grep -v "is deprecated:.*SA1019" "${SC_OUT}"
-# Only ignore the following deprecated types/fields/functions.
-not grep -Fv '.HandleResolvedAddrs
-.HandleSubConnStateChange
-.HeaderMap
-.NewAddress
-.NewServiceConfig
-.Metadata is deprecated: use Attributes
-.Type is deprecated: use Attributes
-.UpdateBalancerState
-balancer.Picker
-grpc.CallCustomCodec
-grpc.Code
-grpc.Compressor
-grpc.Decompressor
-grpc.MaxMsgSize
-grpc.MethodConfig
-grpc.NewGZIPCompressor
-grpc.NewGZIPDecompressor
-grpc.RPCCompressor
-grpc.RPCDecompressor
-grpc.RoundRobin
-grpc.ServiceConfig
-grpc.WithBalancer
-grpc.WithBalancerName
-grpc.WithCompressor
-grpc.WithDecompressor
-grpc.WithDialer
-grpc.WithMaxMsgSize
-grpc.WithServiceConfig
-grpc.WithTimeout
-http.CloseNotifier
-info.SecurityVersion
-naming.Resolver
-naming.Update
-naming.Watcher
-resolver.Backend
-resolver.GRPCLB' "${SC_OUT}"
-
-echo SUCCESS
+# TODO(dfawley): don't use deprecated functions in examples.
+staticcheck -go 1.9 -checks 'inherit,-ST1015' -ignore '
+google.golang.org/grpc/balancer.go:SA1019
+google.golang.org/grpc/balancer/grpclb/grpclb_remote_balancer.go:SA1019
+google.golang.org/grpc/balancer/grpclb/grpclb_test.go:SA1019
+google.golang.org/grpc/balancer/roundrobin/roundrobin_test.go:SA1019
+google.golang.org/grpc/xds/internal/balancer/edsbalancer/balancergroup.go:SA1019
+google.golang.org/grpc/xds/internal/resolver/xds_resolver.go:SA1019
+google.golang.org/grpc/xds/internal/balancer/xds.go:SA1019
+google.golang.org/grpc/xds/internal/balancer/xds_client.go:SA1019
+google.golang.org/grpc/balancer_conn_wrappers.go:SA1019
+google.golang.org/grpc/balancer_test.go:SA1019
+google.golang.org/grpc/benchmark/benchmain/main.go:SA1019
+google.golang.org/grpc/benchmark/worker/benchmark_client.go:SA1019
+google.golang.org/grpc/clientconn.go:S1024
+google.golang.org/grpc/clientconn_state_transition_test.go:SA1019
+google.golang.org/grpc/clientconn_test.go:SA1019
+google.golang.org/grpc/examples/features/debugging/client/main.go:SA1019
+google.golang.org/grpc/examples/features/load_balancing/client/main.go:SA1019
+google.golang.org/grpc/internal/transport/handler_server.go:SA1019
+google.golang.org/grpc/internal/transport/handler_server_test.go:SA1019
+google.golang.org/grpc/internal/resolver/dns/dns_resolver.go:SA1019
+google.golang.org/grpc/stats/stats_test.go:SA1019
+google.golang.org/grpc/test/balancer_test.go:SA1019
+google.golang.org/grpc/test/channelz_test.go:SA1019
+google.golang.org/grpc/test/end2end_test.go:SA1019
+google.golang.org/grpc/test/healthcheck_test.go:SA1019
+' ./...
+misspell -error .