diff --git a/vendor/google.golang.org/grpc/internal/backoff/backoff.go b/vendor/google.golang.org/grpc/internal/backoff/backoff.go
index 1bd0cce..5fc0ee3 100644
--- a/vendor/google.golang.org/grpc/internal/backoff/backoff.go
+++ b/vendor/google.golang.org/grpc/internal/backoff/backoff.go
@@ -25,44 +25,39 @@
 import (
 	"time"
 
+	grpcbackoff "google.golang.org/grpc/backoff"
 	"google.golang.org/grpc/internal/grpcrand"
 )
 
 // Strategy defines the methodology for backing off after a grpc connection
 // failure.
-//
 type Strategy interface {
 	// Backoff returns the amount of time to wait before the next retry given
 	// the number of consecutive failures.
 	Backoff(retries int) time.Duration
 }
 
-const (
-	// baseDelay is the amount of time to wait before retrying after the first
-	// failure.
-	baseDelay = 1.0 * time.Second
-	// factor is applied to the backoff after each retry.
-	factor = 1.6
-	// jitter provides a range to randomize backoff delays.
-	jitter = 0.2
-)
+// DefaultExponential is an exponential backoff implementation using the
+// default values for all the configurable knobs defined in
+// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
+var DefaultExponential = Exponential{Config: grpcbackoff.DefaultConfig}
 
 // Exponential implements exponential backoff algorithm as defined in
 // https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
 type Exponential struct {
-	// MaxDelay is the upper bound of backoff delay.
-	MaxDelay time.Duration
+	// Config contains all options to configure the backoff algorithm.
+	Config grpcbackoff.Config
 }
 
 // Backoff returns the amount of time to wait before the next retry given the
 // number of retries.
 func (bc Exponential) Backoff(retries int) time.Duration {
 	if retries == 0 {
-		return baseDelay
+		return bc.Config.BaseDelay
 	}
-	backoff, max := float64(baseDelay), float64(bc.MaxDelay)
+	backoff, max := float64(bc.Config.BaseDelay), float64(bc.Config.MaxDelay)
 	for backoff < max && retries > 0 {
-		backoff *= factor
+		backoff *= bc.Config.Multiplier
 		retries--
 	}
 	if backoff > max {
@@ -70,7 +65,7 @@
 	}
 	// Randomize backoff delays so that if a cluster of requests start at
 	// the same time, they won't operate in lockstep.
-	backoff *= 1 + jitter*(grpcrand.Float64()*2-1)
+	backoff *= 1 + bc.Config.Jitter*(grpcrand.Float64()*2-1)
 	if backoff < 0 {
 		return 0
 	}
diff --git a/vendor/google.golang.org/grpc/internal/binarylog/binarylog.go b/vendor/google.golang.org/grpc/internal/binarylog/binarylog.go
index fee6aec..8b10516 100644
--- a/vendor/google.golang.org/grpc/internal/binarylog/binarylog.go
+++ b/vendor/google.golang.org/grpc/internal/binarylog/binarylog.go
@@ -34,7 +34,7 @@
 }
 
 // binLogger is the global binary logger for the binary. One of this should be
-// built at init time from the configuration (environment varialbe or flags).
+// built at init time from the configuration (environment variable or flags).
 //
 // It is used to get a methodLogger for each individual method.
 var binLogger Logger
@@ -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 rules for service %v found", service)
+		return fmt.Errorf("conflicting service 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 rules for method %v found", method)
+		return fmt.Errorf("conflicting blacklist rules for method %v found", method)
 	}
 	if _, ok := l.methods[method]; ok {
-		return fmt.Errorf("conflicting rules for method %v found", method)
+		return fmt.Errorf("conflicting method 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 rules for method %v found", method)
+		return fmt.Errorf("conflicting blacklist rules for method %v found", method)
 	}
 	if _, ok := l.methods[method]; ok {
-		return fmt.Errorf("conflicting rules for method %v found", method)
+		return fmt.Errorf("conflicting method 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/binarylog/env_config.go b/vendor/google.golang.org/grpc/internal/binarylog/env_config.go
index 4cc2525..be30d0e 100644
--- a/vendor/google.golang.org/grpc/internal/binarylog/env_config.go
+++ b/vendor/google.golang.org/grpc/internal/binarylog/env_config.go
@@ -43,7 +43,7 @@
 //    Foo.
 //
 // If two configs exist for one certain method or service, the one specified
-// later overrides the privous config.
+// later overrides the previous config.
 func NewLoggerFromConfigString(s string) Logger {
 	if s == "" {
 		return nil
@@ -74,7 +74,7 @@
 			return fmt.Errorf("invalid config: %q, %v", config, err)
 		}
 		if m == "*" {
-			return fmt.Errorf("invalid config: %q, %v", config, "* not allowd in blacklist config")
+			return fmt.Errorf("invalid config: %q, %v", config, "* not allowed in blacklist config")
 		}
 		if suffix != "" {
 			return fmt.Errorf("invalid config: %q, %v", config, "header/message limit not allowed in blacklist config")
diff --git a/vendor/google.golang.org/grpc/internal/binarylog/sink.go b/vendor/google.golang.org/grpc/internal/binarylog/sink.go
index 20d044f..a2e7c34 100644
--- a/vendor/google.golang.org/grpc/internal/binarylog/sink.go
+++ b/vendor/google.golang.org/grpc/internal/binarylog/sink.go
@@ -63,7 +63,7 @@
 
 // newWriterSink creates a binary log sink with the given writer.
 //
-// Write() marshalls the proto message and writes it to the given writer. Each
+// Write() marshals the proto message and writes it to the given writer. Each
 // message is prefixed with a 4 byte big endian unsigned integer as the length.
 //
 // No buffer is done, Close() doesn't try to close the writer.
diff --git a/vendor/google.golang.org/grpc/internal/buffer/unbounded.go b/vendor/google.golang.org/grpc/internal/buffer/unbounded.go
new file mode 100644
index 0000000..9f6a0c1
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/buffer/unbounded.go
@@ -0,0 +1,85 @@
+/*
+ * 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 buffer provides an implementation of an unbounded buffer.
+package buffer
+
+import "sync"
+
+// Unbounded is an implementation of an unbounded buffer which does not use
+// extra goroutines. This is typically used for passing updates from one entity
+// to another within gRPC.
+//
+// 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
+	backlog []interface{}
+}
+
+// NewUnbounded returns a new instance of Unbounded.
+func NewUnbounded() *Unbounded {
+	return &Unbounded{c: make(chan interface{}, 1)}
+}
+
+// Put adds t to the unbounded buffer.
+func (b *Unbounded) Put(t interface{}) {
+	b.mu.Lock()
+	if len(b.backlog) == 0 {
+		select {
+		case b.c <- t:
+			b.mu.Unlock()
+			return
+		default:
+		}
+	}
+	b.backlog = append(b.backlog, t)
+	b.mu.Unlock()
+}
+
+// Load sends the earliest buffered data, if any, onto the read channel
+// returned by Get(). Users are expected to call this every time they read a
+// value from the read channel.
+func (b *Unbounded) Load() {
+	b.mu.Lock()
+	if len(b.backlog) > 0 {
+		select {
+		case b.c <- b.backlog[0]:
+			b.backlog[0] = nil
+			b.backlog = b.backlog[1:]
+		default:
+		}
+	}
+	b.mu.Unlock()
+}
+
+// Get returns a read channel on which values added to the buffer, via Put(),
+// are sent on.
+//
+// Upon reading a value from this channel, users are expected to call Load() to
+// send the next buffered value onto the channel if there is any.
+func (b *Unbounded) Get() <-chan interface{} {
+	return b.c
+}
diff --git a/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go b/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go
index 11be7cd..ae6c897 100644
--- a/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go
+++ b/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go
@@ -25,40 +25,14 @@
 )
 
 const (
-	prefix              = "GRPC_GO_"
-	retryStr            = prefix + "RETRY"
-	requireHandshakeStr = prefix + "REQUIRE_HANDSHAKE"
-)
-
-// RequireHandshakeSetting describes the settings for handshaking.
-type RequireHandshakeSetting int
-
-const (
-	// RequireHandshakeOn indicates to wait for handshake before considering a
-	// connection ready/successful.
-	RequireHandshakeOn RequireHandshakeSetting = iota
-	// RequireHandshakeOff indicates to not wait for handshake before
-	// considering a connection ready/successful.
-	RequireHandshakeOff
+	prefix          = "GRPC_GO_"
+	retryStr        = prefix + "RETRY"
+	txtErrIgnoreStr = prefix + "IGNORE_TXT_ERRORS"
 )
 
 var (
 	// Retry is set if retry is explicitly enabled via "GRPC_GO_RETRY=on".
 	Retry = strings.EqualFold(os.Getenv(retryStr), "on")
-	// RequireHandshake is set based upon the GRPC_GO_REQUIRE_HANDSHAKE
-	// environment variable.
-	//
-	// Will be removed after the 1.18 release.
-	RequireHandshake = RequireHandshakeOn
+	// TXTErrIgnore is set if TXT errors should be ignored ("GRPC_GO_IGNORE_TXT_ERRORS" is not "false").
+	TXTErrIgnore = !strings.EqualFold(os.Getenv(retryStr), "false")
 )
-
-func init() {
-	switch strings.ToLower(os.Getenv(requireHandshakeStr)) {
-	case "on":
-		fallthrough
-	default:
-		RequireHandshake = RequireHandshakeOn
-	case "off":
-		RequireHandshake = RequireHandshakeOff
-	}
-}
diff --git a/vendor/google.golang.org/grpc/internal/internal.go b/vendor/google.golang.org/grpc/internal/internal.go
index bc1f99a..0912f0b 100644
--- a/vendor/google.golang.org/grpc/internal/internal.go
+++ b/vendor/google.golang.org/grpc/internal/internal.go
@@ -28,9 +28,7 @@
 )
 
 var (
-	// WithResolverBuilder is exported by dialoptions.go
-	WithResolverBuilder interface{} // func (resolver.Builder) grpc.DialOption
-	// WithHealthCheckFunc is not exported by dialoptions.go
+	// WithHealthCheckFunc is set by dialoptions.go
 	WithHealthCheckFunc interface{} // func (HealthChecker) DialOption
 	// HealthCheckFunc is used to provide client-side LB channel health checking
 	HealthCheckFunc HealthChecker
@@ -39,14 +37,17 @@
 	// 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
-	// ParseServiceConfig is a function to parse JSON service configs into
-	// opaque data structures.
-	ParseServiceConfig func(sc string) (interface{}, error)
 	// 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
+	// ParseServiceConfigForTesting is for creating a fake
+	// ClientConn for resolver testing only
+	ParseServiceConfigForTesting interface{} // func(string) *serviceconfig.ParseResult
 )
 
 // HealthChecker defines the signature of the client-side LB channel health checking function.
@@ -57,7 +58,7 @@
 //
 // 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), serviceName string) error
+type HealthChecker func(ctx context.Context, newStream func(string) (interface{}, error), setConnectivityState func(connectivity.State, error), 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
new file mode 100644
index 0000000..c368db6
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go
@@ -0,0 +1,441 @@
+/*
+ *
+ * Copyright 2018 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 implements a dns resolver to be installed as the default resolver
+// in grpc.
+package dns
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal/envconfig"
+	"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"
+	defaultDNSSvrPort = "53"
+	golang            = "GO"
+	// txtPrefix is the prefix string to be prepended to the host name for txt record lookup.
+	txtPrefix = "_grpc_config."
+	// In DNS, service config is encoded in a TXT record via the mechanism
+	// described in RFC-1464 using the attribute name grpc_config.
+	txtAttribute = "grpc_config="
+)
+
+var (
+	errMissingAddr = errors.New("dns resolver: missing address")
+
+	// Addresses ending with a colon that is supposed to be the separator
+	// between host and port is not allowed.  E.g. "::" is a valid address as
+	// it is an IPv6 address (host only) and "[::]:" is invalid as it ends with
+	// a colon as the host and port separator
+	errEndsWithColon = errors.New("dns resolver: missing port after port-separator colon")
+)
+
+var (
+	defaultResolver netResolver = net.DefaultResolver
+	// To prevent excessive re-resolution, we enforce a rate limit on DNS
+	// resolution requests.
+	minDNSResRate = 30 * time.Second
+)
+
+var customAuthorityDialler = func(authority string) func(ctx context.Context, network, address string) (net.Conn, error) {
+	return func(ctx context.Context, network, address string) (net.Conn, error) {
+		var dialer net.Dialer
+		return dialer.DialContext(ctx, network, authority)
+	}
+}
+
+var customAuthorityResolver = func(authority string) (netResolver, error) {
+	host, port, err := parseTarget(authority, defaultDNSSvrPort)
+	if err != nil {
+		return nil, err
+	}
+
+	authorityWithPort := net.JoinHostPort(host, port)
+
+	return &net.Resolver{
+		PreferGo: true,
+		Dial:     customAuthorityDialler(authorityWithPort),
+	}, nil
+}
+
+// NewBuilder creates a dnsBuilder which is used to factory DNS resolvers.
+func NewBuilder() resolver.Builder {
+	return &dnsBuilder{}
+}
+
+type dnsBuilder struct{}
+
+// 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) {
+	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
+	}
+
+	// DNS address (non-IP).
+	ctx, cancel := context.WithCancel(context.Background())
+	d := &dnsResolver{
+		host:                 host,
+		port:                 port,
+		ctx:                  ctx,
+		cancel:               cancel,
+		cc:                   cc,
+		rn:                   make(chan struct{}, 1),
+		disableServiceConfig: opts.DisableServiceConfig,
+	}
+
+	if target.Authority == "" {
+		d.resolver = defaultResolver
+	} else {
+		d.resolver, err = customAuthorityResolver(target.Authority)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	d.wg.Add(1)
+	go d.watcher()
+	d.ResolveNow(resolver.ResolveNowOptions{})
+	return d, nil
+}
+
+// Scheme returns the naming scheme of this resolver builder, which is "dns".
+func (b *dnsBuilder) Scheme() string {
+	return "dns"
+}
+
+type netResolver interface {
+	LookupHost(ctx context.Context, host string) (addrs []string, err error)
+	LookupSRV(ctx context.Context, service, proto, name string) (cname string, addrs []*net.SRV, err error)
+	LookupTXT(ctx context.Context, name string) (txts []string, err error)
+}
+
+// deadResolver is a resolver that does nothing.
+type deadResolver struct{}
+
+func (deadResolver) ResolveNow(resolver.ResolveNowOptions) {}
+
+func (deadResolver) Close() {}
+
+// 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
+	// rn channel is used by ResolveNow() to force an immediate resolution of the target.
+	rn chan struct{}
+	// 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.
+	// If Close() doesn't wait for watcher() goroutine finishes, race detector sometimes
+	// will warns lookup (READ the lookup function pointers) inside watcher() goroutine
+	// has data race with replaceNetFunc (WRITE the lookup function pointers).
+	wg                   sync.WaitGroup
+	disableServiceConfig bool
+}
+
+// ResolveNow invoke an immediate resolution of the target that this dnsResolver watches.
+func (d *dnsResolver) ResolveNow(resolver.ResolveNowOptions) {
+	select {
+	case d.rn <- struct{}{}:
+	default:
+	}
+}
+
+// Close closes the dnsResolver.
+func (d *dnsResolver) Close() {
+	d.cancel()
+	d.wg.Wait()
+}
+
+func (d *dnsResolver) watcher() {
+	defer d.wg.Done()
+	for {
+		select {
+		case <-d.ctx.Done():
+			return
+		case <-d.rn:
+		}
+
+		state, err := d.lookup()
+		if err != nil {
+			d.cc.ReportError(err)
+		} else {
+			d.cc.UpdateState(*state)
+		}
+
+		// Sleep to prevent excessive re-resolutions. Incoming resolution requests
+		// will be queued in d.rn.
+		t := time.NewTimer(minDNSResRate)
+		select {
+		case <-t.C:
+		case <-d.ctx.Done():
+			t.Stop()
+			return
+		}
+	}
+}
+
+func (d *dnsResolver) lookupSRV() ([]resolver.Address, error) {
+	if !EnableSRVLookups {
+		return nil, nil
+	}
+	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
+	}
+	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
+		}
+		for _, a := range lbAddrs {
+			ip, ok := formatIP(a)
+			if !ok {
+				return nil, fmt.Errorf("dns: error parsing A record IP address %v", a)
+			}
+			addr := ip + ":" + strconv.Itoa(int(s.Port))
+			newAddrs = append(newAddrs, resolver.Address{Addr: addr, Type: resolver.GRPCLB, ServerName: s.Target})
+		}
+	}
+	return newAddrs, nil
+}
+
+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 {
+	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
+	}
+	var res string
+	for _, s := range ss {
+		res += s
+	}
+
+	// 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
+	}
+	sc := canaryingSC(strings.TrimPrefix(res, txtAttribute))
+	return d.cc.ParseServiceConfig(sc)
+}
+
+func (d *dnsResolver) lookupHost() ([]resolver.Address, error) {
+	var newAddrs []resolver.Address
+	addrs, err := d.resolver.LookupHost(d.ctx, d.host)
+	if err != nil {
+		err = handleDNSError(err, "A")
+		return nil, err
+	}
+	for _, a := range addrs {
+		ip, ok := formatIP(a)
+		if !ok {
+			return nil, fmt.Errorf("dns: error parsing A record IP address %v", a)
+		}
+		addr := ip + ":" + d.port
+		newAddrs = append(newAddrs, resolver.Address{Addr: addr})
+	}
+	return newAddrs, nil
+}
+
+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
+	}
+	state := &resolver.State{
+		Addresses: append(addrs, srv...),
+	}
+	if !d.disableServiceConfig {
+		state.ServiceConfig = d.lookupTXT()
+	}
+	return state, nil
+}
+
+// formatIP returns ok = false if addr is not a valid textual representation of an IP address.
+// If addr is an IPv4 address, return the addr and ok = true.
+// If addr is an IPv6 address, return the addr enclosed in square brackets and ok = true.
+func formatIP(addr string) (addrIP string, ok bool) {
+	ip := net.ParseIP(addr)
+	if ip == nil {
+		return "", false
+	}
+	if ip.To4() != nil {
+		return addr, true
+	}
+	return "[" + addr + "]", true
+}
+
+// parseTarget takes the user input target string and default port, returns formatted host and port info.
+// If target doesn't specify a port, set the port to be the defaultPort.
+// If target is in IPv6 format and host-name is enclosed in square brackets, brackets
+// are stripped when setting the host.
+// examples:
+// target: "www.google.com" defaultPort: "443" returns host: "www.google.com", port: "443"
+// target: "ipv4-host:80" defaultPort: "443" returns host: "ipv4-host", port: "80"
+// target: "[ipv6-host]" defaultPort: "443" returns host: "ipv6-host", port: "443"
+// target: ":80" defaultPort: "443" returns host: "localhost", port: "80"
+func parseTarget(target, defaultPort string) (host, port string, err error) {
+	if target == "" {
+		return "", "", errMissingAddr
+	}
+	if ip := net.ParseIP(target); ip != nil {
+		// target is an IPv4 or IPv6(without brackets) address
+		return target, defaultPort, nil
+	}
+	if host, port, err = net.SplitHostPort(target); err == nil {
+		if port == "" {
+			// If the port field is empty (target ends with colon), e.g. "[::1]:", this is an error.
+			return "", "", errEndsWithColon
+		}
+		// target has port, i.e ipv4-host:port, [ipv6-host]:port, host-name:port
+		if host == "" {
+			// Keep consistent with net.Dial(): If the host is empty, as in ":80", the local system is assumed.
+			host = "localhost"
+		}
+		return host, port, nil
+	}
+	if host, port, err = net.SplitHostPort(target + ":" + defaultPort); err == nil {
+		// target doesn't have port
+		return host, port, nil
+	}
+	return "", "", fmt.Errorf("invalid target address %v, error info: %v", target, err)
+}
+
+type rawChoice struct {
+	ClientLanguage *[]string        `json:"clientLanguage,omitempty"`
+	Percentage     *int             `json:"percentage,omitempty"`
+	ClientHostName *[]string        `json:"clientHostName,omitempty"`
+	ServiceConfig  *json.RawMessage `json:"serviceConfig,omitempty"`
+}
+
+func containsString(a *[]string, b string) bool {
+	if a == nil {
+		return true
+	}
+	for _, c := range *a {
+		if c == b {
+			return true
+		}
+	}
+	return false
+}
+
+func chosenByPercentage(a *int) bool {
+	if a == nil {
+		return true
+	}
+	return grpcrand.Intn(100)+1 <= *a
+}
+
+func canaryingSC(js string) string {
+	if js == "" {
+		return ""
+	}
+	var rcs []rawChoice
+	err := json.Unmarshal([]byte(js), &rcs)
+	if err != nil {
+		grpclog.Warningf("dns: error parsing service config json: %v", err)
+		return ""
+	}
+	cliHostname, err := os.Hostname()
+	if err != nil {
+		grpclog.Warningf("dns: error getting client hostname: %v", err)
+		return ""
+	}
+	var sc string
+	for _, c := range rcs {
+		if !containsString(c.ClientLanguage, golang) ||
+			!chosenByPercentage(c.Percentage) ||
+			!containsString(c.ClientHostName, cliHostname) ||
+			c.ServiceConfig == nil {
+			continue
+		}
+		sc = string(*c.ServiceConfig)
+		break
+	}
+	return sc
+}
diff --git a/vendor/google.golang.org/grpc/internal/resolver/dns/go113.go b/vendor/google.golang.org/grpc/internal/resolver/dns/go113.go
new file mode 100644
index 0000000..8783a8c
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/resolver/dns/go113.go
@@ -0,0 +1,33 @@
+// +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
new file mode 100644
index 0000000..520d922
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/resolver/passthrough/passthrough.go
@@ -0,0 +1,57 @@
+/*
+ *
+ * Copyright 2017 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 passthrough implements a pass-through resolver. It sends the target
+// name without scheme back to gRPC as resolved address.
+package passthrough
+
+import "google.golang.org/grpc/resolver"
+
+const scheme = "passthrough"
+
+type passthroughBuilder struct{}
+
+func (*passthroughBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
+	r := &passthroughResolver{
+		target: target,
+		cc:     cc,
+	}
+	r.start()
+	return r, nil
+}
+
+func (*passthroughBuilder) Scheme() string {
+	return scheme
+}
+
+type passthroughResolver struct {
+	target resolver.Target
+	cc     resolver.ClientConn
+}
+
+func (r *passthroughResolver) start() {
+	r.cc.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: r.target.Endpoint}}})
+}
+
+func (*passthroughResolver) ResolveNow(o resolver.ResolveNowOptions) {}
+
+func (*passthroughResolver) Close() {}
+
+func init() {
+	resolver.Register(&passthroughBuilder{})
+}
diff --git a/vendor/google.golang.org/grpc/internal/transport/controlbuf.go b/vendor/google.golang.org/grpc/internal/transport/controlbuf.go
index 204ba15..ddee20b 100644
--- a/vendor/google.golang.org/grpc/internal/transport/controlbuf.go
+++ b/vendor/google.golang.org/grpc/internal/transport/controlbuf.go
@@ -23,6 +23,7 @@
 	"fmt"
 	"runtime"
 	"sync"
+	"sync/atomic"
 
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
@@ -84,24 +85,40 @@
 // the control buffer of transport. They represent different aspects of
 // control tasks, e.g., flow control, settings, streaming resetting, etc.
 
+// maxQueuedTransportResponseFrames is the most queued "transport response"
+// frames we will buffer before preventing new reads from occurring on the
+// transport.  These are control frames sent in response to client requests,
+// such as RST_STREAM due to bad headers or settings acks.
+const maxQueuedTransportResponseFrames = 50
+
+type cbItem interface {
+	isTransportResponseFrame() bool
+}
+
 // registerStream is used to register an incoming stream with loopy writer.
 type registerStream struct {
 	streamID uint32
 	wq       *writeQuota
 }
 
+func (*registerStream) isTransportResponseFrame() bool { return false }
+
 // headerFrame is also used to register stream on the client-side.
 type headerFrame struct {
 	streamID   uint32
 	hf         []hpack.HeaderField
-	endStream  bool                       // Valid on server side.
-	initStream func(uint32) (bool, error) // Used only on the client side.
+	endStream  bool               // Valid on server side.
+	initStream func(uint32) error // Used only on the client side.
 	onWrite    func()
 	wq         *writeQuota    // write quota for the stream created.
 	cleanup    *cleanupStream // Valid on the server side.
 	onOrphaned func(error)    // Valid on client-side
 }
 
+func (h *headerFrame) isTransportResponseFrame() bool {
+	return h.cleanup != nil && h.cleanup.rst // Results in a RST_STREAM
+}
+
 type cleanupStream struct {
 	streamID uint32
 	rst      bool
@@ -109,6 +126,8 @@
 	onWrite  func()
 }
 
+func (c *cleanupStream) isTransportResponseFrame() bool { return c.rst } // Results in a RST_STREAM
+
 type dataFrame struct {
 	streamID  uint32
 	endStream bool
@@ -119,27 +138,41 @@
 	onEachWrite func()
 }
 
+func (*dataFrame) isTransportResponseFrame() bool { return false }
+
 type incomingWindowUpdate struct {
 	streamID  uint32
 	increment uint32
 }
 
+func (*incomingWindowUpdate) isTransportResponseFrame() bool { return false }
+
 type outgoingWindowUpdate struct {
 	streamID  uint32
 	increment uint32
 }
 
+func (*outgoingWindowUpdate) isTransportResponseFrame() bool {
+	return false // window updates are throttled by thresholds
+}
+
 type incomingSettings struct {
 	ss []http2.Setting
 }
 
+func (*incomingSettings) isTransportResponseFrame() bool { return true } // Results in a settings ACK
+
 type outgoingSettings struct {
 	ss []http2.Setting
 }
 
+func (*outgoingSettings) isTransportResponseFrame() bool { return false }
+
 type incomingGoAway struct {
 }
 
+func (*incomingGoAway) isTransportResponseFrame() bool { return false }
+
 type goAway struct {
 	code      http2.ErrCode
 	debugData []byte
@@ -147,15 +180,21 @@
 	closeConn bool
 }
 
+func (*goAway) isTransportResponseFrame() bool { return false }
+
 type ping struct {
 	ack  bool
 	data [8]byte
 }
 
+func (*ping) isTransportResponseFrame() bool { return true }
+
 type outFlowControlSizeRequest struct {
 	resp chan uint32
 }
 
+func (*outFlowControlSizeRequest) isTransportResponseFrame() bool { return false }
+
 type outStreamState int
 
 const (
@@ -238,6 +277,14 @@
 	consumerWaiting bool
 	list            *itemList
 	err             error
+
+	// transportResponseFrames counts the number of queued items that represent
+	// the response of an action initiated by the peer.  trfChan is created
+	// when transportResponseFrames >= maxQueuedTransportResponseFrames and is
+	// closed and nilled when transportResponseFrames drops below the
+	// threshold.  Both fields are protected by mu.
+	transportResponseFrames int
+	trfChan                 atomic.Value // *chan struct{}
 }
 
 func newControlBuffer(done <-chan struct{}) *controlBuffer {
@@ -248,12 +295,24 @@
 	}
 }
 
-func (c *controlBuffer) put(it interface{}) error {
+// throttle blocks if there are too many incomingSettings/cleanupStreams in the
+// controlbuf.
+func (c *controlBuffer) throttle() {
+	ch, _ := c.trfChan.Load().(*chan struct{})
+	if ch != nil {
+		select {
+		case <-*ch:
+		case <-c.done:
+		}
+	}
+}
+
+func (c *controlBuffer) put(it cbItem) error {
 	_, err := c.executeAndPut(nil, it)
 	return err
 }
 
-func (c *controlBuffer) executeAndPut(f func(it interface{}) bool, it interface{}) (bool, error) {
+func (c *controlBuffer) executeAndPut(f func(it interface{}) bool, it cbItem) (bool, error) {
 	var wakeUp bool
 	c.mu.Lock()
 	if c.err != nil {
@@ -271,6 +330,15 @@
 		c.consumerWaiting = false
 	}
 	c.list.enqueue(it)
+	if it.isTransportResponseFrame() {
+		c.transportResponseFrames++
+		if c.transportResponseFrames == maxQueuedTransportResponseFrames {
+			// We are adding the frame that puts us over the threshold; create
+			// a throttling channel.
+			ch := make(chan struct{})
+			c.trfChan.Store(&ch)
+		}
+	}
 	c.mu.Unlock()
 	if wakeUp {
 		select {
@@ -304,7 +372,17 @@
 			return nil, c.err
 		}
 		if !c.list.isEmpty() {
-			h := c.list.dequeue()
+			h := c.list.dequeue().(cbItem)
+			if h.isTransportResponseFrame() {
+				if c.transportResponseFrames == maxQueuedTransportResponseFrames {
+					// We are removing the frame that put us over the
+					// threshold; close and clear the throttling channel.
+					ch := c.trfChan.Load().(*chan struct{})
+					close(*ch)
+					c.trfChan.Store((*chan struct{})(nil))
+				}
+				c.transportResponseFrames--
+			}
 			c.mu.Unlock()
 			return h, nil
 		}
@@ -559,21 +637,17 @@
 
 func (l *loopyWriter) originateStream(str *outStream) error {
 	hdr := str.itl.dequeue().(*headerFrame)
-	sendPing, err := hdr.initStream(str.id)
-	if err != nil {
+	if err := hdr.initStream(str.id); err != nil {
 		if err == ErrConnClosing {
 			return err
 		}
 		// Other errors(errStreamDrain) need not close transport.
 		return nil
 	}
-	if err = l.writeHeader(str.id, hdr.endStream, hdr.hf, hdr.onWrite); err != nil {
+	if err := l.writeHeader(str.id, hdr.endStream, hdr.hf, hdr.onWrite); err != nil {
 		return err
 	}
 	l.estdStreams[str.id] = str
-	if sendPing {
-		return l.pingHandler(&ping{data: [8]byte{}})
-	}
 	return nil
 }
 
diff --git a/vendor/google.golang.org/grpc/internal/transport/flowcontrol.go b/vendor/google.golang.org/grpc/internal/transport/flowcontrol.go
index 5ea997a..f262edd 100644
--- a/vendor/google.golang.org/grpc/internal/transport/flowcontrol.go
+++ b/vendor/google.golang.org/grpc/internal/transport/flowcontrol.go
@@ -149,6 +149,7 @@
 		n = uint32(math.MaxInt32)
 	}
 	f.mu.Lock()
+	defer f.mu.Unlock()
 	// estSenderQuota is the receiver's view of the maximum number of bytes the sender
 	// can send without a window update.
 	estSenderQuota := int32(f.limit - (f.pendingData + f.pendingUpdate))
@@ -169,10 +170,8 @@
 			// is padded; We will fallback on the current available window(at least a 1/4th of the limit).
 			f.delta = n
 		}
-		f.mu.Unlock()
 		return f.delta
 	}
-	f.mu.Unlock()
 	return 0
 }
 
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 78f9ddc..c3c32da 100644
--- a/vendor/google.golang.org/grpc/internal/transport/handler_server.go
+++ b/vendor/google.golang.org/grpc/internal/transport/handler_server.go
@@ -227,7 +227,9 @@
 
 	if err == nil { // transport has not been closed
 		if ht.stats != nil {
-			ht.stats.HandleRPC(s.Context(), &stats.OutTrailer{})
+			ht.stats.HandleRPC(s.Context(), &stats.OutTrailer{
+				Trailer: s.trailer.Copy(),
+			})
 		}
 	}
 	ht.Close()
@@ -289,7 +291,9 @@
 
 	if err == nil {
 		if ht.stats != nil {
-			ht.stats.HandleRPC(s.Context(), &stats.OutHeader{})
+			ht.stats.HandleRPC(s.Context(), &stats.OutHeader{
+				Header: md.Copy(),
+			})
 		}
 	}
 	return err
@@ -334,7 +338,7 @@
 		Addr: ht.RemoteAddr(),
 	}
 	if req.TLS != nil {
-		pr.AuthInfo = credentials.TLSInfo{State: *req.TLS}
+		pr.AuthInfo = credentials.TLSInfo{State: *req.TLS, CommonAuthInfo: credentials.CommonAuthInfo{credentials.PrivacyAndIntegrity}}
 	}
 	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 c96178d..2d6feeb 100644
--- a/vendor/google.golang.org/grpc/internal/transport/http2_client.go
+++ b/vendor/google.golang.org/grpc/internal/transport/http2_client.go
@@ -35,6 +35,7 @@
 
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/syscall"
 	"google.golang.org/grpc/keepalive"
@@ -44,8 +45,14 @@
 	"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.
 	ctx        context.Context
 	cancel     context.CancelFunc
 	ctxDone    <-chan struct{} // Cache the ctx.Done() chan.
@@ -62,8 +69,6 @@
 	// goAway is closed to notify the upper layer (i.e., addrConn.transportMonitor)
 	// that the server sent GoAway on this transport.
 	goAway chan struct{}
-	// awakenKeepalive is used to wake up keepalive when after it has gone dormant.
-	awakenKeepalive chan struct{}
 
 	framer *framer
 	// controlBuf delivers all the control related tasks (e.g., window
@@ -77,9 +82,6 @@
 
 	perRPCCreds []credentials.PerRPCCredentials
 
-	// Boolean to keep track of reading activity on transport.
-	// 1 is true and 0 is false.
-	activity         uint32 // Accessed atomically.
 	kp               keepalive.ClientParameters
 	keepaliveEnabled bool
 
@@ -110,6 +112,16 @@
 	// goAwayReason records the http2.ErrCode and debug data received with the
 	// GoAway frame.
 	goAwayReason GoAwayReason
+	// A condition variable used to signal when the keepalive goroutine should
+	// go dormant. The condition for dormancy is based on the number of active
+	// streams and the `PermitWithoutStream` keepalive client parameter. And
+	// since the number of active streams is guarded by the above mutex, we use
+	// the same for this condition variable as well.
+	kpDormancyCond *sync.Cond
+	// A boolean to track whether the keepalive goroutine is dormant or not.
+	// This is checked before attempting to signal the above condition
+	// variable.
+	kpDormant bool
 
 	// Fields below are for channelz metric collection.
 	channelzID int64 // channelz unique identification number
@@ -119,6 +131,8 @@
 	onClose  func()
 
 	bufferPool *bufferPool
+
+	connectionID uint64
 }
 
 func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error), addr string) (net.Conn, error) {
@@ -232,7 +246,6 @@
 		readerDone:            make(chan struct{}),
 		writerDone:            make(chan struct{}),
 		goAway:                make(chan struct{}),
-		awakenKeepalive:       make(chan struct{}, 1),
 		framer:                newFramer(conn, writeBufSize, readBufSize, maxHeaderListSize),
 		fc:                    &trInFlow{limit: uint32(icwz)},
 		scheme:                scheme,
@@ -264,9 +277,6 @@
 			updateFlowControl: t.updateFlowControl,
 		}
 	}
-	// Make sure awakenKeepalive can't be written upon.
-	// keepalive routine will make it writable, if need be.
-	t.awakenKeepalive <- struct{}{}
 	if t.statsHandler != nil {
 		t.ctx = t.statsHandler.TagConn(t.ctx, &stats.ConnTagInfo{
 			RemoteAddr: t.remoteAddr,
@@ -281,6 +291,7 @@
 		t.channelzID = channelz.RegisterNormalSocket(t, opts.ChannelzParentID, fmt.Sprintf("%s -> %s", t.localAddr, t.remoteAddr))
 	}
 	if t.keepaliveEnabled {
+		t.kpDormancyCond = sync.NewCond(&t.mu)
 		go t.keepalive()
 	}
 	// Start the reader goroutine for incoming message. Each transport has
@@ -325,6 +336,8 @@
 		}
 	}
 
+	t.connectionID = atomic.AddUint64(&clientConnectionCounter, 1)
+
 	if err := t.framer.writer.Flush(); err != nil {
 		return nil, err
 	}
@@ -347,6 +360,7 @@
 func (t *http2Client) newStream(ctx context.Context, callHdr *CallHdr) *Stream {
 	// TODO(zhaoq): Handle uint32 overflow of Stream.id.
 	s := &Stream{
+		ct:             t,
 		done:           make(chan struct{}),
 		method:         callHdr.Method,
 		sendCompress:   callHdr.SendCompress,
@@ -380,23 +394,24 @@
 }
 
 func (t *http2Client) getPeer() *peer.Peer {
-	pr := &peer.Peer{
-		Addr: t.remoteAddr,
+	return &peer.Peer{
+		Addr:     t.remoteAddr,
+		AuthInfo: t.authInfo,
 	}
-	// Attach Auth info if there is any.
-	if t.authInfo != nil {
-		pr.AuthInfo = t.authInfo
-	}
-	return pr
 }
 
 func (t *http2Client) createHeaderFields(ctx context.Context, callHdr *CallHdr) ([]hpack.HeaderField, error) {
 	aud := t.createAudience(callHdr)
-	authData, err := t.getTrAuthData(ctx, aud)
+	ri := credentials.RequestInfo{
+		Method:   callHdr.Method,
+		AuthInfo: t.authInfo,
+	}
+	ctxWithRequestInfo := internal.NewRequestInfoContext.(func(context.Context, credentials.RequestInfo) context.Context)(ctx, ri)
+	authData, err := t.getTrAuthData(ctxWithRequestInfo, aud)
 	if err != nil {
 		return nil, err
 	}
-	callAuthData, err := t.getCallAuthData(ctx, aud, callHdr)
+	callAuthData, err := t.getCallAuthData(ctxWithRequestInfo, aud, callHdr)
 	if err != nil {
 		return nil, err
 	}
@@ -419,6 +434,7 @@
 
 	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.
@@ -493,6 +509,9 @@
 }
 
 func (t *http2Client) getTrAuthData(ctx context.Context, audience string) (map[string]string, error) {
+	if len(t.perRPCCreds) == 0 {
+		return nil, nil
+	}
 	authData := map[string]string{}
 	for _, c := range t.perRPCCreds {
 		data, err := c.GetRequestMetadata(ctx, audience)
@@ -513,7 +532,7 @@
 }
 
 func (t *http2Client) getCallAuthData(ctx context.Context, audience string, callHdr *CallHdr) (map[string]string, error) {
-	callAuthData := map[string]string{}
+	var callAuthData map[string]string
 	// Check if credentials.PerRPCCredentials were provided via call options.
 	// Note: if these credentials are provided both via dial options and call
 	// options, then both sets of credentials will be applied.
@@ -525,6 +544,7 @@
 		if err != nil {
 			return nil, status.Errorf(codes.Internal, "transport: %v", err)
 		}
+		callAuthData = make(map[string]string, len(data))
 		for k, v := range data {
 			// Capital header names are illegal in HTTP/2
 			k = strings.ToLower(k)
@@ -556,12 +576,11 @@
 		if atomic.CompareAndSwapUint32(&s.headerChanClosed, 0, 1) {
 			close(s.headerChan)
 		}
-
 	}
 	hdr := &headerFrame{
 		hf:        headerFields,
 		endStream: false,
-		initStream: func(id uint32) (bool, error) {
+		initStream: func(id uint32) error {
 			t.mu.Lock()
 			if state := t.state; state != reachable {
 				t.mu.Unlock()
@@ -571,29 +590,19 @@
 					err = ErrConnClosing
 				}
 				cleanup(err)
-				return false, err
+				return err
 			}
 			t.activeStreams[id] = s
 			if channelz.IsOn() {
 				atomic.AddInt64(&t.czData.streamsStarted, 1)
 				atomic.StoreInt64(&t.czData.lastStreamCreatedTime, time.Now().UnixNano())
 			}
-			var sendPing bool
-			// If the number of active streams change from 0 to 1, then check if keepalive
-			// has gone dormant. If so, wake it up.
-			if len(t.activeStreams) == 1 && t.keepaliveEnabled {
-				select {
-				case t.awakenKeepalive <- struct{}{}:
-					sendPing = true
-					// Fill the awakenKeepalive channel again as this channel must be
-					// kept non-writable except at the point that the keepalive()
-					// goroutine is waiting either to be awaken or shutdown.
-					t.awakenKeepalive <- struct{}{}
-				default:
-				}
+			// If the keepalive goroutine has gone dormant, wake it up.
+			if t.kpDormant {
+				t.kpDormancyCond.Signal()
 			}
 			t.mu.Unlock()
-			return sendPing, nil
+			return nil
 		},
 		onOrphaned: cleanup,
 		wq:         s.wq,
@@ -671,12 +680,14 @@
 		}
 	}
 	if t.statsHandler != nil {
+		header, _, _ := metadata.FromOutgoingContextRaw(ctx)
 		outHeader := &stats.OutHeader{
 			Client:      true,
 			FullMethod:  callHdr.Method,
 			RemoteAddr:  t.remoteAddr,
 			LocalAddr:   t.localAddr,
 			Compression: callHdr.SendCompress,
+			Header:      header.Copy(),
 		}
 		t.statsHandler.HandleRPC(s.ctx, outHeader)
 	}
@@ -769,9 +780,17 @@
 		t.mu.Unlock()
 		return nil
 	}
+	// Call t.onClose before setting the state to closing to prevent the client
+	// from attempting to create new streams ASAP.
+	t.onClose()
 	t.state = closing
 	streams := t.activeStreams
 	t.activeStreams = nil
+	if t.kpDormant {
+		// If the keepalive goroutine is blocked on this condition variable, we
+		// should unblock it so that the goroutine eventually exits.
+		t.kpDormancyCond.Signal()
+	}
 	t.mu.Unlock()
 	t.controlBuf.finish()
 	t.cancel()
@@ -789,7 +808,6 @@
 		}
 		t.statsHandler.HandleConn(t.ctx, connEnd)
 	}
-	t.onClose()
 	return err
 }
 
@@ -848,11 +866,11 @@
 	return t.controlBuf.put(df)
 }
 
-func (t *http2Client) getStream(f http2.Frame) (*Stream, bool) {
+func (t *http2Client) getStream(f http2.Frame) *Stream {
 	t.mu.Lock()
-	defer t.mu.Unlock()
-	s, ok := t.activeStreams[f.Header().StreamID]
-	return s, ok
+	s := t.activeStreams[f.Header().StreamID]
+	t.mu.Unlock()
+	return s
 }
 
 // adjustWindow sends out extra window update over the initial window size
@@ -932,8 +950,8 @@
 		t.controlBuf.put(bdpPing)
 	}
 	// Select the right stream to dispatch.
-	s, ok := t.getStream(f)
-	if !ok {
+	s := t.getStream(f)
+	if s == nil {
 		return
 	}
 	if size > 0 {
@@ -964,8 +982,8 @@
 }
 
 func (t *http2Client) handleRSTStream(f *http2.RSTStreamFrame) {
-	s, ok := t.getStream(f)
-	if !ok {
+	s := t.getStream(f)
+	if s == nil {
 		return
 	}
 	if f.ErrCode == http2.ErrCodeRefusedStream {
@@ -978,9 +996,9 @@
 		statusCode = codes.Unknown
 	}
 	if statusCode == codes.Canceled {
-		// Our deadline was already exceeded, and that was likely the cause of
-		// this cancelation.  Alter the status code accordingly.
-		if d, ok := s.ctx.Deadline(); ok && d.After(time.Now()) {
+		if d, ok := s.ctx.Deadline(); ok && !d.After(time.Now()) {
+			// Our deadline was already exceeded, and that was likely the cause
+			// of this cancelation.  Alter the status code accordingly.
 			statusCode = codes.DeadlineExceeded
 		}
 	}
@@ -1085,11 +1103,12 @@
 	default:
 		t.setGoAwayReason(f)
 		close(t.goAway)
-		t.state = draining
 		t.controlBuf.put(&incomingGoAway{})
-
-		// This has to be a new goroutine because we're still using the current goroutine to read in the transport.
+		// Notify the clientconn about the GOAWAY before we set the state to
+		// draining, to allow the client to stop attempting to create streams
+		// before disallowing new streams on this connection.
 		t.onGoAway(t.goAwayReason)
+		t.state = draining
 	}
 	// All streams with IDs greater than the GoAwayId
 	// and smaller than the previous GoAway ID should be killed.
@@ -1141,8 +1160,8 @@
 
 // operateHeaders takes action on the decoded headers.
 func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
-	s, ok := t.getStream(frame)
-	if !ok {
+	s := t.getStream(frame)
+	if s == nil {
 		return
 	}
 	endStream := frame.StreamEnded()
@@ -1171,12 +1190,14 @@
 				inHeader := &stats.InHeader{
 					Client:     true,
 					WireLength: int(frame.Header().Length),
+					Header:     s.header.Copy(),
 				}
 				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)
 			}
@@ -1185,6 +1206,7 @@
 
 	// If headerChan hasn't been closed yet
 	if atomic.CompareAndSwapUint32(&s.headerChanClosed, 0, 1) {
+		s.headerValid = true
 		if !endStream {
 			// HEADERS frame block carries a Response-Headers.
 			isHeader = true
@@ -1227,7 +1249,7 @@
 	}
 	t.conn.SetReadDeadline(time.Time{}) // reset deadline once we get the settings frame (we didn't time out, yay!)
 	if t.keepaliveEnabled {
-		atomic.CompareAndSwapUint32(&t.activity, 0, 1)
+		atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
 	}
 	sf, ok := frame.(*http2.SettingsFrame)
 	if !ok {
@@ -1239,9 +1261,10 @@
 
 	// loop to keep reading incoming messages on this transport.
 	for {
+		t.controlBuf.throttle()
 		frame, err := t.framer.fr.ReadFrame()
 		if t.keepaliveEnabled {
-			atomic.CompareAndSwapUint32(&t.activity, 0, 1)
+			atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
 		}
 		if err != nil {
 			// Abort an active stream if the http2.Framer returns a
@@ -1285,55 +1308,83 @@
 	}
 }
 
+func minTime(a, b time.Duration) time.Duration {
+	if a < b {
+		return a
+	}
+	return b
+}
+
 // keepalive running in a separate goroutune makes sure the connection is alive by sending pings.
 func (t *http2Client) keepalive() {
 	p := &ping{data: [8]byte{}}
+	// 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.
+	timeoutLeft := 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()
 	timer := time.NewTimer(t.kp.Time)
 	for {
 		select {
 		case <-timer.C:
-			if atomic.CompareAndSwapUint32(&t.activity, 1, 0) {
-				timer.Reset(t.kp.Time)
+			lastRead := atomic.LoadInt64(&t.lastRead)
+			if lastRead > prevNano {
+				// There has been read activity since the last time we were here.
+				outstandingPing = false
+				// Next timer should fire at kp.Time seconds from lastRead time.
+				timer.Reset(time.Duration(lastRead) + t.kp.Time - time.Duration(time.Now().UnixNano()))
+				prevNano = lastRead
 				continue
 			}
-			// Check if keepalive should go dormant.
+			if outstandingPing && timeoutLeft <= 0 {
+				t.Close()
+				return
+			}
 			t.mu.Lock()
+			if t.state == closing {
+				// If the transport is closing, we should exit from the
+				// keepalive goroutine here. If not, we could have a race
+				// between the call to Signal() from Close() and the call to
+				// Wait() here, whereby the keepalive goroutine ends up
+				// blocking on the condition variable which will never be
+				// signalled again.
+				t.mu.Unlock()
+				return
+			}
 			if len(t.activeStreams) < 1 && !t.kp.PermitWithoutStream {
-				// Make awakenKeepalive writable.
-				<-t.awakenKeepalive
-				t.mu.Unlock()
-				select {
-				case <-t.awakenKeepalive:
-					// If the control gets here a ping has been sent
-					// need to reset the timer with keepalive.Timeout.
-				case <-t.ctx.Done():
-					return
-				}
-			} else {
-				t.mu.Unlock()
+				// If a ping was sent out previously (because there were active
+				// streams at that point) which wasn't acked and its timeout
+				// hadn't fired, but we got here and are about to go dormant,
+				// we should make sure that we unconditionally send a ping once
+				// we awaken.
+				outstandingPing = false
+				t.kpDormant = true
+				t.kpDormancyCond.Wait()
+			}
+			t.kpDormant = false
+			t.mu.Unlock()
+
+			// We get here either because we were dormant and a new stream was
+			// created which unblocked the Wait() call, or because the
+			// keepalive timer expired. In both cases, we need to send a ping.
+			if !outstandingPing {
 				if channelz.IsOn() {
 					atomic.AddInt64(&t.czData.kpCount, 1)
 				}
-				// Send ping.
 				t.controlBuf.put(p)
+				timeoutLeft = t.kp.Timeout
+				outstandingPing = true
 			}
-
-			// By the time control gets here a ping has been sent one way or the other.
-			timer.Reset(t.kp.Timeout)
-			select {
-			case <-timer.C:
-				if atomic.CompareAndSwapUint32(&t.activity, 1, 0) {
-					timer.Reset(t.kp.Time)
-					continue
-				}
-				t.Close()
-				return
-			case <-t.ctx.Done():
-				if !timer.Stop() {
-					<-timer.C
-				}
-				return
-			}
+			// 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, timeoutLeft)
+			timeoutLeft -= sleepDuration
+			timer.Reset(sleepDuration)
 		case <-t.ctx.Done():
 			if !timer.Stop() {
 				<-timer.C
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 150b73e..8b04b03 100644
--- a/vendor/google.golang.org/grpc/internal/transport/http2_server.go
+++ b/vendor/google.golang.org/grpc/internal/transport/http2_server.go
@@ -62,11 +62,15 @@
 	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
-	ctxDone     <-chan struct{} // Cache the context.Done() chan
-	cancel      context.CancelFunc
+	done        chan struct{}
 	conn        net.Conn
 	loopy       *loopyWriter
 	readerDone  chan struct{} // sync point to enable testing.
@@ -84,12 +88,8 @@
 	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.
@@ -125,6 +125,8 @@
 	channelzID int64 // channelz unique identification number
 	czData     *channelzData
 	bufferPool *bufferPool
+
+	connectionID uint64
 }
 
 // newHTTP2Server constructs a ServerTransport based on HTTP2. ConnectionError is
@@ -138,7 +140,10 @@
 	}
 	framer := newFramer(conn, writeBufSize, readBufSize, maxHeaderListSize)
 	// Send initial settings as connection preface to client.
-	var isettings []http2.Setting
+	isettings := []http2.Setting{{
+		ID:  http2.SettingMaxFrameSize,
+		Val: http2MaxFrameLen,
+	}}
 	// TODO(zhaoq): Have a better way to signal "no limit" because 0 is
 	// permitted in the HTTP2 spec.
 	maxStreams := config.MaxStreams
@@ -172,6 +177,12 @@
 			Val: *config.MaxHeaderListSize,
 		})
 	}
+	if config.HeaderTableSize != nil {
+		isettings = append(isettings, http2.Setting{
+			ID:  http2.SettingHeaderTableSize,
+			Val: *config.HeaderTableSize,
+		})
+	}
 	if err := framer.fr.WriteSettings(isettings...); err != nil {
 		return nil, connectionErrorf(false, err, "transport: %v", err)
 	}
@@ -203,11 +214,10 @@
 	if kep.MinTime == 0 {
 		kep.MinTime = defaultKeepalivePolicyMinTime
 	}
-	ctx, cancel := context.WithCancel(context.Background())
+	done := make(chan struct{})
 	t := &http2Server{
-		ctx:               ctx,
-		cancel:            cancel,
-		ctxDone:           ctx.Done(),
+		ctx:               context.Background(),
+		done:              done,
 		conn:              conn,
 		remoteAddr:        conn.RemoteAddr(),
 		localAddr:         conn.LocalAddr(),
@@ -228,7 +238,7 @@
 		czData:            new(channelzData),
 		bufferPool:        newBufferPool(),
 	}
-	t.controlBuf = newControlBuffer(t.ctxDone)
+	t.controlBuf = newControlBuffer(t.done)
 	if dynamicWindow {
 		t.bdpEst = &bdpEstimator{
 			bdp:               initialWindowSize,
@@ -246,6 +256,9 @@
 	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() {
@@ -270,7 +283,7 @@
 	if err != nil {
 		return nil, connectionErrorf(false, err, "transport: http2Server.HandleStreams failed to read initial settings frame: %v", err)
 	}
-	atomic.StoreUint32(&t.activity, 1)
+	atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
 	sf, ok := frame.(*http2.SettingsFrame)
 	if !ok {
 		return nil, connectionErrorf(false, nil, "transport: http2Server.HandleStreams saw invalid preface type %T from client", frame)
@@ -359,12 +372,14 @@
 				rstCode:  http2.ErrCodeRefusedStream,
 				onWrite:  func() {},
 			})
+			s.cancel()
 			return false
 		}
 	}
 	t.mu.Lock()
 	if t.state != reachable {
 		t.mu.Unlock()
+		s.cancel()
 		return false
 	}
 	if uint32(len(t.activeStreams)) >= t.maxStreams {
@@ -375,12 +390,14 @@
 			rstCode:  http2.ErrCodeRefusedStream,
 			onWrite:  func() {},
 		})
+		s.cancel()
 		return false
 	}
 	if streamID%2 != 1 || streamID <= t.maxStreamID {
 		t.mu.Unlock()
 		// illegal gRPC stream id.
 		errorf("transport: http2Server.HandleStreams received an illegal stream id: %v", streamID)
+		s.cancel()
 		return true
 	}
 	t.maxStreamID = streamID
@@ -405,6 +422,7 @@
 			LocalAddr:   t.localAddr,
 			Compression: s.recvCompress,
 			WireLength:  int(frame.Header().Length),
+			Header:      metadata.MD(state.data.mdata).Copy(),
 		}
 		t.stats.HandleRPC(s.ctx, inHeader)
 	}
@@ -436,8 +454,9 @@
 func (t *http2Server) HandleStreams(handle func(*Stream), traceCtx func(context.Context, string) context.Context) {
 	defer close(t.readerDone)
 	for {
+		t.controlBuf.throttle()
 		frame, err := t.framer.fr.ReadFrame()
-		atomic.StoreUint32(&t.activity, 1)
+		atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
 		if err != nil {
 			if se, ok := err.(http2.StreamError); ok {
 				warningf("transport: http2Server.HandleStreams encountered http2.StreamError: %v", se)
@@ -745,7 +764,7 @@
 	return true
 }
 
-// WriteHeader sends the header metedata md back to the client.
+// WriteHeader sends the header metadata md back to the client.
 func (t *http2Server) WriteHeader(s *Stream, md metadata.MD) error {
 	if s.updateHeaderSent() || s.getState() == streamDone {
 		return ErrIllegalHeaderWrite
@@ -766,6 +785,10 @@
 	return nil
 }
 
+func (t *http2Server) setResetPingStrikes() {
+	atomic.StoreUint32(&t.resetPingStrikes, 1)
+}
+
 func (t *http2Server) writeHeaderLocked(s *Stream) error {
 	// TODO(mmukhi): Benchmark if the performance gets better if count the metadata and other header fields
 	// first and create a slice of that exact size.
@@ -780,9 +803,7 @@
 		streamID:  s.id,
 		hf:        headerFields,
 		endStream: false,
-		onWrite: func() {
-			atomic.StoreUint32(&t.resetPingStrikes, 1)
-		},
+		onWrite:   t.setResetPingStrikes,
 	})
 	if !success {
 		if err != nil {
@@ -794,7 +815,9 @@
 	if t.stats != nil {
 		// Note: WireLength is not set in outHeader.
 		// TODO(mmukhi): Revisit this later, if needed.
-		outHeader := &stats.OutHeader{}
+		outHeader := &stats.OutHeader{
+			Header: s.header.Copy(),
+		}
 		t.stats.HandleRPC(s.Context(), outHeader)
 	}
 	return nil
@@ -842,9 +865,7 @@
 		streamID:  s.id,
 		hf:        headerFields,
 		endStream: true,
-		onWrite: func() {
-			atomic.StoreUint32(&t.resetPingStrikes, 1)
-		},
+		onWrite:   t.setResetPingStrikes,
 	}
 	s.hdrMu.Unlock()
 	success, err := t.controlBuf.execute(t.checkForHeaderListSize, trailingHeader)
@@ -859,7 +880,9 @@
 	rst := s.getState() == streamActive
 	t.finishStream(s, rst, http2.ErrCodeNo, trailingHeader, true)
 	if t.stats != nil {
-		t.stats.HandleRPC(s.Context(), &stats.OutTrailer{})
+		t.stats.HandleRPC(s.Context(), &stats.OutTrailer{
+			Trailer: s.trailer.Copy(),
+		})
 	}
 	return nil
 }
@@ -881,7 +904,7 @@
 			// TODO(mmukhi, dfawley): Should the server write also return io.EOF?
 			s.cancel()
 			select {
-			case <-t.ctx.Done():
+			case <-t.done:
 				return ErrConnClosing
 			default:
 			}
@@ -896,16 +919,14 @@
 	hdr = append(hdr, data[:emptyLen]...)
 	data = data[emptyLen:]
 	df := &dataFrame{
-		streamID: s.id,
-		h:        hdr,
-		d:        data,
-		onEachWrite: func() {
-			atomic.StoreUint32(&t.resetPingStrikes, 1)
-		},
+		streamID:    s.id,
+		h:           hdr,
+		d:           data,
+		onEachWrite: t.setResetPingStrikes,
 	}
 	if err := s.wq.get(int32(len(hdr) + len(data))); err != nil {
 		select {
-		case <-t.ctx.Done():
+		case <-t.done:
 			return ErrConnClosing
 		default:
 		}
@@ -922,32 +943,35 @@
 // after an additional duration of keepalive.Timeout.
 func (t *http2Server) keepalive() {
 	p := &ping{}
-	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.
+	// 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)
 	defer func() {
-		if !maxIdle.Stop() {
-			<-maxIdle.C
-		}
-		if !maxAge.Stop() {
-			<-maxAge.C
-		}
-		if !keepalive.Stop() {
-			<-keepalive.C
-		}
+		// 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()
 	}()
+
 	for {
 		select {
-		case <-maxIdle.C:
+		case <-idleTimer.C:
 			t.mu.Lock()
 			idle := t.idle
 			if idle.IsZero() { // The connection is non-idle.
 				t.mu.Unlock()
-				maxIdle.Reset(t.kp.MaxConnectionIdle)
+				idleTimer.Reset(t.kp.MaxConnectionIdle)
 				continue
 			}
 			val := t.kp.MaxConnectionIdle - time.Since(idle)
@@ -956,42 +980,52 @@
 				// 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
 			}
-			maxIdle.Reset(val)
-		case <-maxAge.C:
+			idleTimer.Reset(val)
+		case <-ageTimer.C:
 			t.drain(http2.ErrCodeNo, []byte{})
-			maxAge.Reset(t.kp.MaxConnectionAgeGrace)
+			ageTimer.Reset(t.kp.MaxConnectionAgeGrace)
 			select {
-			case <-maxAge.C:
+			case <-ageTimer.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.ctx.Done():
+			case <-t.done:
 			}
 			return
-		case <-keepalive.C:
-			if atomic.CompareAndSwapUint32(&t.activity, 1, 0) {
-				pingSent = false
-				keepalive.Reset(t.kp.Time)
+		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
 				continue
 			}
-			if pingSent {
+			if outstandingPing && kpTimeoutLeft <= 0 {
+				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
 			}
-			pingSent = true
-			if channelz.IsOn() {
-				atomic.AddInt64(&t.czData.kpCount, 1)
+			if !outstandingPing {
+				if channelz.IsOn() {
+					atomic.AddInt64(&t.czData.kpCount, 1)
+				}
+				t.controlBuf.put(p)
+				kpTimeoutLeft = t.kp.Timeout
+				outstandingPing = true
 			}
-			t.controlBuf.put(p)
-			keepalive.Reset(t.kp.Timeout)
-		case <-t.ctx.Done():
+			// 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)
+		case <-t.done:
 			return
 		}
 	}
@@ -1011,7 +1045,7 @@
 	t.activeStreams = nil
 	t.mu.Unlock()
 	t.controlBuf.finish()
-	t.cancel()
+	close(t.done)
 	err := t.conn.Close()
 	if channelz.IsOn() {
 		channelz.RemoveEntry(t.channelzID)
@@ -1151,7 +1185,7 @@
 		select {
 		case <-t.drainChan:
 		case <-timer.C:
-		case <-t.ctx.Done():
+		case <-t.done:
 			return
 		}
 		t.controlBuf.put(&goAway{code: g.code, debugData: g.debugData})
@@ -1201,7 +1235,7 @@
 	select {
 	case sz := <-resp:
 		return int64(sz)
-	case <-t.ctxDone:
+	case <-t.done:
 		return -1
 	case <-timer.C:
 		return -2
diff --git a/vendor/google.golang.org/grpc/internal/transport/http_util.go b/vendor/google.golang.org/grpc/internal/transport/http_util.go
index 9d21286..8f5f334 100644
--- a/vendor/google.golang.org/grpc/internal/transport/http_util.go
+++ b/vendor/google.golang.org/grpc/internal/transport/http_util.go
@@ -667,6 +667,7 @@
 		writer: w,
 		fr:     http2.NewFramer(w, r),
 	}
+	f.fr.SetMaxReadFrameSize(http2MaxFrameLen)
 	// Opt-in to Frame reuse API on framer to reduce garbage.
 	// Frames aren't safe to read from after a subsequent call to ReadFrame.
 	f.fr.SetReuseFrames()
diff --git a/vendor/google.golang.org/grpc/internal/transport/transport.go b/vendor/google.golang.org/grpc/internal/transport/transport.go
index 0f33c9c..a30da9e 100644
--- a/vendor/google.golang.org/grpc/internal/transport/transport.go
+++ b/vendor/google.golang.org/grpc/internal/transport/transport.go
@@ -73,10 +73,11 @@
 }
 
 // recvBuffer is an unbounded channel of recvMsg structs.
-// 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"
+//
+// 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"
 type recvBuffer struct {
 	c       chan recvMsg
 	mu      sync.Mutex
@@ -184,6 +185,19 @@
 	// r.readAdditional acts on that message and returns the necessary error.
 	select {
 	case <-r.ctxDone:
+		// Note that this adds the ctx error to the end of recv buffer, and
+		// reads from the head. This will delay the error until recv buffer is
+		// empty, thus will delay ctx cancellation in Recv().
+		//
+		// It's done this way to fix a race between ctx cancel and trailer. The
+		// race was, stream.Recv() may return ctx error if ctxDone wins the
+		// race, but stream.Trailer() may return a non-nil md because the stream
+		// was not marked as done when trailer is received. This closeStream
+		// call will mark stream as done, thus fix the race.
+		//
+		// TODO: delaying ctx error seems like a unnecessary side effect. What
+		// we really want is to mark the stream as done, and return ctx error
+		// faster.
 		r.closeStream(ContextErr(r.ctx.Err()))
 		m := <-r.recv.get()
 		return r.readAdditional(m, p)
@@ -220,6 +234,7 @@
 type Stream struct {
 	id           uint32
 	st           ServerTransport    // nil for client side Stream
+	ct           *http2Client       // nil for server side Stream
 	ctx          context.Context    // the associated context of the stream
 	cancel       context.CancelFunc // always nil for client side Stream
 	done         chan struct{}      // closed at the end of stream to unblock writers. On the client side.
@@ -238,6 +253,10 @@
 
 	headerChan       chan struct{} // closed to indicate the end of header metadata.
 	headerChanClosed uint32        // set when headerChan is closed. Used to avoid closing headerChan multiple times.
+	// headerValid indicates whether a valid header was received.  Only
+	// meaningful after headerChan is closed (always call waitOnHeader() before
+	// reading its value).  Not valid on server side.
+	headerValid bool
 
 	// hdrMu protects header and trailer metadata on the server-side.
 	hdrMu sync.Mutex
@@ -290,26 +309,28 @@
 	return streamState(atomic.LoadUint32((*uint32)(&s.state)))
 }
 
-func (s *Stream) waitOnHeader() error {
+func (s *Stream) waitOnHeader() {
 	if s.headerChan == nil {
 		// On the server headerChan is always nil since a stream originates
 		// only after having received headers.
-		return nil
+		return
 	}
 	select {
 	case <-s.ctx.Done():
-		return ContextErr(s.ctx.Err())
+		// Close the stream to prevent headers/trailers from changing after
+		// this function returns.
+		s.ct.CloseStream(s, ContextErr(s.ctx.Err()))
+		// headerChan could possibly not be closed yet if closeStream raced
+		// with operateHeaders; wait until it is closed explicitly here.
+		<-s.headerChan
 	case <-s.headerChan:
-		return nil
 	}
 }
 
 // RecvCompress returns the compression algorithm applied to the inbound
 // message. It is empty string if there is no compression applied.
 func (s *Stream) RecvCompress() string {
-	if err := s.waitOnHeader(); err != nil {
-		return ""
-	}
+	s.waitOnHeader()
 	return s.recvCompress
 }
 
@@ -330,36 +351,27 @@
 // available. It blocks until i) the metadata is ready or ii) there is no header
 // metadata or iii) the stream is canceled/expired.
 //
-// On server side, it returns the out header after t.WriteHeader is called.
+// On server side, it returns the out header after t.WriteHeader is called.  It
+// does not block and must not be called until after WriteHeader.
 func (s *Stream) Header() (metadata.MD, error) {
-	if s.headerChan == nil && s.header != nil {
+	if s.headerChan == nil {
 		// On server side, return the header in stream. It will be the out
 		// header after t.WriteHeader is called.
 		return s.header.Copy(), nil
 	}
-	err := s.waitOnHeader()
-	// Even if the stream is closed, header is returned if available.
-	select {
-	case <-s.headerChan:
-		if s.header == nil {
-			return nil, nil
-		}
-		return s.header.Copy(), nil
-	default:
+	s.waitOnHeader()
+	if !s.headerValid {
+		return nil, s.status.Err()
 	}
-	return nil, err
+	return s.header.Copy(), nil
 }
 
 // TrailersOnly blocks until a header or trailers-only frame is received and
 // then returns true if the stream was trailers-only.  If the stream ends
-// before headers are received, returns true, nil.  If a context error happens
-// first, returns it as a status error.  Client-side only.
-func (s *Stream) TrailersOnly() (bool, error) {
-	err := s.waitOnHeader()
-	if err != nil {
-		return false, err
-	}
-	return s.noHeaders, nil
+// before headers are received, returns true, nil.  Client-side only.
+func (s *Stream) TrailersOnly() bool {
+	s.waitOnHeader()
+	return s.noHeaders
 }
 
 // Trailer returns the cached trailer metedata. Note that if it is not called
@@ -513,6 +525,7 @@
 	ReadBufferSize        int
 	ChannelzParentID      int64
 	MaxHeaderListSize     *uint32
+	HeaderTableSize       *uint32
 }
 
 // NewServerTransport creates a ServerTransport with conn or non-nil error