[VOL-5291] On demand statistics for ONU and OLT

Change-Id: I4850bb0f0d2235122cb0c1bcf835b3672bb34436
Signed-off-by: Akash Reddy Kankanala <akash.kankanala@radisys.com>
diff --git a/vendor/google.golang.org/grpc/internal/balancer/gracefulswitch/gracefulswitch.go b/vendor/google.golang.org/grpc/internal/balancer/gracefulswitch/gracefulswitch.go
new file mode 100644
index 0000000..08666f6
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/balancer/gracefulswitch/gracefulswitch.go
@@ -0,0 +1,384 @@
+/*
+ *
+ * Copyright 2022 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 gracefulswitch implements a graceful switch load balancer.
+package gracefulswitch
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/balancer/base"
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/resolver"
+)
+
+var errBalancerClosed = errors.New("gracefulSwitchBalancer is closed")
+var _ balancer.Balancer = (*Balancer)(nil)
+
+// NewBalancer returns a graceful switch Balancer.
+func NewBalancer(cc balancer.ClientConn, opts balancer.BuildOptions) *Balancer {
+	return &Balancer{
+		cc:    cc,
+		bOpts: opts,
+	}
+}
+
+// Balancer is a utility to gracefully switch from one balancer to
+// a new balancer. It implements the balancer.Balancer interface.
+type Balancer struct {
+	bOpts balancer.BuildOptions
+	cc    balancer.ClientConn
+
+	// mu protects the following fields and all fields within balancerCurrent
+	// and balancerPending. mu does not need to be held when calling into the
+	// child balancers, as all calls into these children happen only as a direct
+	// result of a call into the gracefulSwitchBalancer, which are also
+	// guaranteed to be synchronous. There is one exception: an UpdateState call
+	// from a child balancer when current and pending are populated can lead to
+	// calling Close() on the current. To prevent that racing with an
+	// UpdateSubConnState from the channel, we hold currentMu during Close and
+	// UpdateSubConnState calls.
+	mu              sync.Mutex
+	balancerCurrent *balancerWrapper
+	balancerPending *balancerWrapper
+	closed          bool // set to true when this balancer is closed
+
+	// currentMu must be locked before mu. This mutex guards against this
+	// sequence of events: UpdateSubConnState() called, finds the
+	// balancerCurrent, gives up lock, updateState comes in, causes Close() on
+	// balancerCurrent before the UpdateSubConnState is called on the
+	// balancerCurrent.
+	currentMu sync.Mutex
+}
+
+// swap swaps out the current lb with the pending lb and updates the ClientConn.
+// The caller must hold gsb.mu.
+func (gsb *Balancer) swap() {
+	gsb.cc.UpdateState(gsb.balancerPending.lastState)
+	cur := gsb.balancerCurrent
+	gsb.balancerCurrent = gsb.balancerPending
+	gsb.balancerPending = nil
+	go func() {
+		gsb.currentMu.Lock()
+		defer gsb.currentMu.Unlock()
+		cur.Close()
+	}()
+}
+
+// Helper function that checks if the balancer passed in is current or pending.
+// The caller must hold gsb.mu.
+func (gsb *Balancer) balancerCurrentOrPending(bw *balancerWrapper) bool {
+	return bw == gsb.balancerCurrent || bw == gsb.balancerPending
+}
+
+// SwitchTo initializes the graceful switch process, which completes based on
+// connectivity state changes on the current/pending balancer. Thus, the switch
+// process is not complete when this method returns. This method must be called
+// synchronously alongside the rest of the balancer.Balancer methods this
+// Graceful Switch Balancer implements.
+func (gsb *Balancer) SwitchTo(builder balancer.Builder) error {
+	gsb.mu.Lock()
+	if gsb.closed {
+		gsb.mu.Unlock()
+		return errBalancerClosed
+	}
+	bw := &balancerWrapper{
+		gsb: gsb,
+		lastState: balancer.State{
+			ConnectivityState: connectivity.Connecting,
+			Picker:            base.NewErrPicker(balancer.ErrNoSubConnAvailable),
+		},
+		subconns: make(map[balancer.SubConn]bool),
+	}
+	balToClose := gsb.balancerPending // nil if there is no pending balancer
+	if gsb.balancerCurrent == nil {
+		gsb.balancerCurrent = bw
+	} else {
+		gsb.balancerPending = bw
+	}
+	gsb.mu.Unlock()
+	balToClose.Close()
+	// This function takes a builder instead of a balancer because builder.Build
+	// can call back inline, and this utility needs to handle the callbacks.
+	newBalancer := builder.Build(bw, gsb.bOpts)
+	if newBalancer == nil {
+		// This is illegal and should never happen; we clear the balancerWrapper
+		// we were constructing if it happens to avoid a potential panic.
+		gsb.mu.Lock()
+		if gsb.balancerPending != nil {
+			gsb.balancerPending = nil
+		} else {
+			gsb.balancerCurrent = nil
+		}
+		gsb.mu.Unlock()
+		return balancer.ErrBadResolverState
+	}
+
+	// This write doesn't need to take gsb.mu because this field never gets read
+	// or written to on any calls from the current or pending. Calls from grpc
+	// to this balancer are guaranteed to be called synchronously, so this
+	// bw.Balancer field will never be forwarded to until this SwitchTo()
+	// function returns.
+	bw.Balancer = newBalancer
+	return nil
+}
+
+// Returns nil if the graceful switch balancer is closed.
+func (gsb *Balancer) latestBalancer() *balancerWrapper {
+	gsb.mu.Lock()
+	defer gsb.mu.Unlock()
+	if gsb.balancerPending != nil {
+		return gsb.balancerPending
+	}
+	return gsb.balancerCurrent
+}
+
+// UpdateClientConnState forwards the update to the latest balancer created.
+func (gsb *Balancer) UpdateClientConnState(state balancer.ClientConnState) error {
+	// The resolver data is only relevant to the most recent LB Policy.
+	balToUpdate := gsb.latestBalancer()
+	if balToUpdate == nil {
+		return errBalancerClosed
+	}
+	// Perform this call without gsb.mu to prevent deadlocks if the child calls
+	// back into the channel. The latest balancer can never be closed during a
+	// call from the channel, even without gsb.mu held.
+	return balToUpdate.UpdateClientConnState(state)
+}
+
+// ResolverError forwards the error to the latest balancer created.
+func (gsb *Balancer) ResolverError(err error) {
+	// The resolver data is only relevant to the most recent LB Policy.
+	balToUpdate := gsb.latestBalancer()
+	if balToUpdate == nil {
+		return
+	}
+	// Perform this call without gsb.mu to prevent deadlocks if the child calls
+	// back into the channel. The latest balancer can never be closed during a
+	// call from the channel, even without gsb.mu held.
+	balToUpdate.ResolverError(err)
+}
+
+// ExitIdle forwards the call to the latest balancer created.
+//
+// If the latest balancer does not support ExitIdle, the subConns are
+// re-connected to manually.
+func (gsb *Balancer) ExitIdle() {
+	balToUpdate := gsb.latestBalancer()
+	if balToUpdate == nil {
+		return
+	}
+	// There is no need to protect this read with a mutex, as the write to the
+	// Balancer field happens in SwitchTo, which completes before this can be
+	// called.
+	if ei, ok := balToUpdate.Balancer.(balancer.ExitIdler); ok {
+		ei.ExitIdle()
+		return
+	}
+	gsb.mu.Lock()
+	defer gsb.mu.Unlock()
+	for sc := range balToUpdate.subconns {
+		sc.Connect()
+	}
+}
+
+// UpdateSubConnState forwards the update to the appropriate child.
+func (gsb *Balancer) UpdateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
+	gsb.currentMu.Lock()
+	defer gsb.currentMu.Unlock()
+	gsb.mu.Lock()
+	// Forward update to the appropriate child.  Even if there is a pending
+	// balancer, the current balancer should continue to get SubConn updates to
+	// maintain the proper state while the pending is still connecting.
+	var balToUpdate *balancerWrapper
+	if gsb.balancerCurrent != nil && gsb.balancerCurrent.subconns[sc] {
+		balToUpdate = gsb.balancerCurrent
+	} else if gsb.balancerPending != nil && gsb.balancerPending.subconns[sc] {
+		balToUpdate = gsb.balancerPending
+	}
+	gsb.mu.Unlock()
+	if balToUpdate == nil {
+		// SubConn belonged to a stale lb policy that has not yet fully closed,
+		// or the balancer was already closed.
+		return
+	}
+	balToUpdate.UpdateSubConnState(sc, state)
+}
+
+// Close closes any active child balancers.
+func (gsb *Balancer) Close() {
+	gsb.mu.Lock()
+	gsb.closed = true
+	currentBalancerToClose := gsb.balancerCurrent
+	gsb.balancerCurrent = nil
+	pendingBalancerToClose := gsb.balancerPending
+	gsb.balancerPending = nil
+	gsb.mu.Unlock()
+
+	currentBalancerToClose.Close()
+	pendingBalancerToClose.Close()
+}
+
+// balancerWrapper wraps a balancer.Balancer, and overrides some Balancer
+// methods to help cleanup SubConns created by the wrapped balancer.
+//
+// It implements the balancer.ClientConn interface and is passed down in that
+// capacity to the wrapped balancer. It maintains a set of subConns created by
+// the wrapped balancer and calls from the latter to create/update/remove
+// SubConns update this set before being forwarded to the parent ClientConn.
+// State updates from the wrapped balancer can result in invocation of the
+// graceful switch logic.
+type balancerWrapper struct {
+	balancer.Balancer
+	gsb *Balancer
+
+	lastState balancer.State
+	subconns  map[balancer.SubConn]bool // subconns created by this balancer
+}
+
+func (bw *balancerWrapper) UpdateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
+	if state.ConnectivityState == connectivity.Shutdown {
+		bw.gsb.mu.Lock()
+		delete(bw.subconns, sc)
+		bw.gsb.mu.Unlock()
+	}
+	// There is no need to protect this read with a mutex, as the write to the
+	// Balancer field happens in SwitchTo, which completes before this can be
+	// called.
+	bw.Balancer.UpdateSubConnState(sc, state)
+}
+
+// Close closes the underlying LB policy and removes the subconns it created. bw
+// must not be referenced via balancerCurrent or balancerPending in gsb when
+// called. gsb.mu must not be held.  Does not panic with a nil receiver.
+func (bw *balancerWrapper) Close() {
+	// before Close is called.
+	if bw == nil {
+		return
+	}
+	// There is no need to protect this read with a mutex, as Close() is
+	// impossible to be called concurrently with the write in SwitchTo(). The
+	// callsites of Close() for this balancer in Graceful Switch Balancer will
+	// never be called until SwitchTo() returns.
+	bw.Balancer.Close()
+	bw.gsb.mu.Lock()
+	for sc := range bw.subconns {
+		bw.gsb.cc.RemoveSubConn(sc)
+	}
+	bw.gsb.mu.Unlock()
+}
+
+func (bw *balancerWrapper) UpdateState(state balancer.State) {
+	// Hold the mutex for this entire call to ensure it cannot occur
+	// concurrently with other updateState() calls. This causes updates to
+	// lastState and calls to cc.UpdateState to happen atomically.
+	bw.gsb.mu.Lock()
+	defer bw.gsb.mu.Unlock()
+	bw.lastState = state
+
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		return
+	}
+
+	if bw == bw.gsb.balancerCurrent {
+		// In the case that the current balancer exits READY, and there is a pending
+		// balancer, you can forward the pending balancer's cached State up to
+		// ClientConn and swap the pending into the current. This is because there
+		// is no reason to gracefully switch from and keep using the old policy as
+		// the ClientConn is not connected to any backends.
+		if state.ConnectivityState != connectivity.Ready && bw.gsb.balancerPending != nil {
+			bw.gsb.swap()
+			return
+		}
+		// Even if there is a pending balancer waiting to be gracefully switched to,
+		// continue to forward current balancer updates to the Client Conn. Ignoring
+		// state + picker from the current would cause undefined behavior/cause the
+		// system to behave incorrectly from the current LB policies perspective.
+		// Also, the current LB is still being used by grpc to choose SubConns per
+		// RPC, and thus should use the most updated form of the current balancer.
+		bw.gsb.cc.UpdateState(state)
+		return
+	}
+	// This method is now dealing with a state update from the pending balancer.
+	// If the current balancer is currently in a state other than READY, the new
+	// policy can be swapped into place immediately. This is because there is no
+	// reason to gracefully switch from and keep using the old policy as the
+	// ClientConn is not connected to any backends.
+	if state.ConnectivityState != connectivity.Connecting || bw.gsb.balancerCurrent.lastState.ConnectivityState != connectivity.Ready {
+		bw.gsb.swap()
+	}
+}
+
+func (bw *balancerWrapper) NewSubConn(addrs []resolver.Address, opts balancer.NewSubConnOptions) (balancer.SubConn, error) {
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		bw.gsb.mu.Unlock()
+		return nil, fmt.Errorf("%T at address %p that called NewSubConn is deleted", bw, bw)
+	}
+	bw.gsb.mu.Unlock()
+
+	sc, err := bw.gsb.cc.NewSubConn(addrs, opts)
+	if err != nil {
+		return nil, err
+	}
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) { // balancer was closed during this call
+		bw.gsb.cc.RemoveSubConn(sc)
+		bw.gsb.mu.Unlock()
+		return nil, fmt.Errorf("%T at address %p that called NewSubConn is deleted", bw, bw)
+	}
+	bw.subconns[sc] = true
+	bw.gsb.mu.Unlock()
+	return sc, nil
+}
+
+func (bw *balancerWrapper) ResolveNow(opts resolver.ResolveNowOptions) {
+	// Ignore ResolveNow requests from anything other than the most recent
+	// balancer, because older balancers were already removed from the config.
+	if bw != bw.gsb.latestBalancer() {
+		return
+	}
+	bw.gsb.cc.ResolveNow(opts)
+}
+
+func (bw *balancerWrapper) RemoveSubConn(sc balancer.SubConn) {
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		bw.gsb.mu.Unlock()
+		return
+	}
+	bw.gsb.mu.Unlock()
+	bw.gsb.cc.RemoveSubConn(sc)
+}
+
+func (bw *balancerWrapper) UpdateAddresses(sc balancer.SubConn, addrs []resolver.Address) {
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		bw.gsb.mu.Unlock()
+		return
+	}
+	bw.gsb.mu.Unlock()
+	bw.gsb.cc.UpdateAddresses(sc, addrs)
+}
+
+func (bw *balancerWrapper) Target() string {
+	return bw.gsb.cc.Target()
+}
diff --git a/vendor/google.golang.org/grpc/internal/binarylog/binarylog.go b/vendor/google.golang.org/grpc/internal/binarylog/binarylog.go
index 5cc3aed..755fdeb 100644
--- a/vendor/google.golang.org/grpc/internal/binarylog/binarylog.go
+++ b/vendor/google.golang.org/grpc/internal/binarylog/binarylog.go
@@ -28,38 +28,48 @@
 	"google.golang.org/grpc/internal/grpcutil"
 )
 
-// Logger is the global binary logger. It can be used to get binary logger for
-// each method.
+var grpclogLogger = grpclog.Component("binarylog")
+
+// Logger specifies MethodLoggers for method names with a Log call that
+// takes a context.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
 type Logger interface {
-	getMethodLogger(methodName string) *MethodLogger
+	GetMethodLogger(methodName string) MethodLogger
 }
 
 // binLogger is the global binary logger for the binary. One of this should be
 // built at init time from the configuration (environment variable or flags).
 //
-// It is used to get a methodLogger for each individual method.
+// It is used to get a MethodLogger for each individual method.
 var binLogger Logger
 
-var grpclogLogger = grpclog.Component("binarylog")
-
-// SetLogger sets the binarg logger.
+// SetLogger sets the binary logger.
 //
 // Only call this at init time.
 func SetLogger(l Logger) {
 	binLogger = l
 }
 
-// GetMethodLogger returns the methodLogger for the given methodName.
+// GetLogger gets the binary logger.
+//
+// Only call this at init time.
+func GetLogger() Logger {
+	return binLogger
+}
+
+// GetMethodLogger returns the MethodLogger for the given methodName.
 //
 // methodName should be in the format of "/service/method".
 //
-// Each methodLogger returned by this method is a new instance. This is to
+// Each MethodLogger returned by this method is a new instance. This is to
 // generate sequence id within the call.
-func GetMethodLogger(methodName string) *MethodLogger {
+func GetMethodLogger(methodName string) MethodLogger {
 	if binLogger == nil {
 		return nil
 	}
-	return binLogger.getMethodLogger(methodName)
+	return binLogger.GetMethodLogger(methodName)
 }
 
 func init() {
@@ -68,17 +78,29 @@
 	binLogger = NewLoggerFromConfigString(configStr)
 }
 
-type methodLoggerConfig struct {
+// MethodLoggerConfig contains the setting for logging behavior of a method
+// logger. Currently, it contains the max length of header and message.
+type MethodLoggerConfig struct {
 	// Max length of header and message.
-	hdr, msg uint64
+	Header, Message uint64
+}
+
+// LoggerConfig contains the config for loggers to create method loggers.
+type LoggerConfig struct {
+	All      *MethodLoggerConfig
+	Services map[string]*MethodLoggerConfig
+	Methods  map[string]*MethodLoggerConfig
+
+	Blacklist map[string]struct{}
 }
 
 type logger struct {
-	all      *methodLoggerConfig
-	services map[string]*methodLoggerConfig
-	methods  map[string]*methodLoggerConfig
+	config LoggerConfig
+}
 
-	blacklist map[string]struct{}
+// NewLoggerFromConfig builds a logger with the given LoggerConfig.
+func NewLoggerFromConfig(config LoggerConfig) Logger {
+	return &logger{config: config}
 }
 
 // newEmptyLogger creates an empty logger. The map fields need to be filled in
@@ -88,83 +110,83 @@
 }
 
 // Set method logger for "*".
-func (l *logger) setDefaultMethodLogger(ml *methodLoggerConfig) error {
-	if l.all != nil {
+func (l *logger) setDefaultMethodLogger(ml *MethodLoggerConfig) error {
+	if l.config.All != nil {
 		return fmt.Errorf("conflicting global rules found")
 	}
-	l.all = ml
+	l.config.All = ml
 	return nil
 }
 
 // Set method logger for "service/*".
 //
-// New methodLogger with same service overrides the old one.
-func (l *logger) setServiceMethodLogger(service string, ml *methodLoggerConfig) error {
-	if _, ok := l.services[service]; ok {
+// New MethodLogger with same service overrides the old one.
+func (l *logger) setServiceMethodLogger(service string, ml *MethodLoggerConfig) error {
+	if _, ok := l.config.Services[service]; ok {
 		return fmt.Errorf("conflicting service rules for service %v found", service)
 	}
-	if l.services == nil {
-		l.services = make(map[string]*methodLoggerConfig)
+	if l.config.Services == nil {
+		l.config.Services = make(map[string]*MethodLoggerConfig)
 	}
-	l.services[service] = ml
+	l.config.Services[service] = ml
 	return nil
 }
 
 // Set method logger for "service/method".
 //
-// New methodLogger with same method overrides the old one.
-func (l *logger) setMethodMethodLogger(method string, ml *methodLoggerConfig) error {
-	if _, ok := l.blacklist[method]; ok {
+// New MethodLogger with same method overrides the old one.
+func (l *logger) setMethodMethodLogger(method string, ml *MethodLoggerConfig) error {
+	if _, ok := l.config.Blacklist[method]; ok {
 		return fmt.Errorf("conflicting blacklist rules for method %v found", method)
 	}
-	if _, ok := l.methods[method]; ok {
+	if _, ok := l.config.Methods[method]; ok {
 		return fmt.Errorf("conflicting method rules for method %v found", method)
 	}
-	if l.methods == nil {
-		l.methods = make(map[string]*methodLoggerConfig)
+	if l.config.Methods == nil {
+		l.config.Methods = make(map[string]*MethodLoggerConfig)
 	}
-	l.methods[method] = ml
+	l.config.Methods[method] = ml
 	return nil
 }
 
 // Set blacklist method for "-service/method".
 func (l *logger) setBlacklist(method string) error {
-	if _, ok := l.blacklist[method]; ok {
+	if _, ok := l.config.Blacklist[method]; ok {
 		return fmt.Errorf("conflicting blacklist rules for method %v found", method)
 	}
-	if _, ok := l.methods[method]; ok {
+	if _, ok := l.config.Methods[method]; ok {
 		return fmt.Errorf("conflicting method rules for method %v found", method)
 	}
-	if l.blacklist == nil {
-		l.blacklist = make(map[string]struct{})
+	if l.config.Blacklist == nil {
+		l.config.Blacklist = make(map[string]struct{})
 	}
-	l.blacklist[method] = struct{}{}
+	l.config.Blacklist[method] = struct{}{}
 	return nil
 }
 
-// getMethodLogger returns the methodLogger for the given methodName.
+// getMethodLogger returns the MethodLogger for the given methodName.
 //
 // methodName should be in the format of "/service/method".
 //
-// Each methodLogger returned by this method is a new instance. This is to
+// Each MethodLogger returned by this method is a new instance. This is to
 // generate sequence id within the call.
-func (l *logger) getMethodLogger(methodName string) *MethodLogger {
+func (l *logger) GetMethodLogger(methodName string) MethodLogger {
 	s, m, err := grpcutil.ParseMethod(methodName)
 	if err != nil {
 		grpclogLogger.Infof("binarylogging: failed to parse %q: %v", methodName, err)
 		return nil
 	}
-	if ml, ok := l.methods[s+"/"+m]; ok {
-		return newMethodLogger(ml.hdr, ml.msg)
+	if ml, ok := l.config.Methods[s+"/"+m]; ok {
+		return NewTruncatingMethodLogger(ml.Header, ml.Message)
 	}
-	if _, ok := l.blacklist[s+"/"+m]; ok {
+	if _, ok := l.config.Blacklist[s+"/"+m]; ok {
 		return nil
 	}
-	if ml, ok := l.services[s]; ok {
-		return newMethodLogger(ml.hdr, ml.msg)
+	if ml, ok := l.config.Services[s]; ok {
+		return NewTruncatingMethodLogger(ml.Header, ml.Message)
 	}
-	if l.all == nil {
+	if l.config.All == nil {
 		return nil
 	}
-	return newMethodLogger(l.all.hdr, l.all.msg)
+	return NewTruncatingMethodLogger(l.config.All.Header, l.config.All.Message)
 }
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 129aa2d..f9e80e2 100644
--- a/vendor/google.golang.org/grpc/internal/binarylog/env_config.go
+++ b/vendor/google.golang.org/grpc/internal/binarylog/env_config.go
@@ -57,7 +57,7 @@
 	return l
 }
 
-// fillMethodLoggerWithConfigString parses config, creates methodLogger and adds
+// fillMethodLoggerWithConfigString parses config, creates TruncatingMethodLogger and adds
 // it to the right map in the logger.
 func (l *logger) fillMethodLoggerWithConfigString(config string) error {
 	// "" is invalid.
@@ -89,7 +89,7 @@
 		if err != nil {
 			return fmt.Errorf("invalid config: %q, %v", config, err)
 		}
-		if err := l.setDefaultMethodLogger(&methodLoggerConfig{hdr: hdr, msg: msg}); err != nil {
+		if err := l.setDefaultMethodLogger(&MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
 			return fmt.Errorf("invalid config: %v", err)
 		}
 		return nil
@@ -104,11 +104,11 @@
 		return fmt.Errorf("invalid header/message length config: %q, %v", suffix, err)
 	}
 	if m == "*" {
-		if err := l.setServiceMethodLogger(s, &methodLoggerConfig{hdr: hdr, msg: msg}); err != nil {
+		if err := l.setServiceMethodLogger(s, &MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
 			return fmt.Errorf("invalid config: %v", err)
 		}
 	} else {
-		if err := l.setMethodMethodLogger(s+"/"+m, &methodLoggerConfig{hdr: hdr, msg: msg}); err != nil {
+		if err := l.setMethodMethodLogger(s+"/"+m, &MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
 			return fmt.Errorf("invalid config: %v", err)
 		}
 	}
diff --git a/vendor/google.golang.org/grpc/internal/binarylog/method_logger.go b/vendor/google.golang.org/grpc/internal/binarylog/method_logger.go
index 0cdb418..6c3f632 100644
--- a/vendor/google.golang.org/grpc/internal/binarylog/method_logger.go
+++ b/vendor/google.golang.org/grpc/internal/binarylog/method_logger.go
@@ -19,6 +19,7 @@
 package binarylog
 
 import (
+	"context"
 	"net"
 	"strings"
 	"sync/atomic"
@@ -26,7 +27,7 @@
 
 	"github.com/golang/protobuf/proto"
 	"github.com/golang/protobuf/ptypes"
-	pb "google.golang.org/grpc/binarylog/grpc_binarylog_v1"
+	binlogpb "google.golang.org/grpc/binarylog/grpc_binarylog_v1"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/status"
 )
@@ -48,7 +49,16 @@
 var idGen callIDGenerator
 
 // MethodLogger is the sub-logger for each method.
-type MethodLogger struct {
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
+type MethodLogger interface {
+	Log(context.Context, LogEntryConfig)
+}
+
+// TruncatingMethodLogger is a method logger that truncates headers and messages
+// based on configured fields.
+type TruncatingMethodLogger struct {
 	headerMaxLen, messageMaxLen uint64
 
 	callID          uint64
@@ -57,8 +67,12 @@
 	sink Sink // TODO(blog): make this plugable.
 }
 
-func newMethodLogger(h, m uint64) *MethodLogger {
-	return &MethodLogger{
+// NewTruncatingMethodLogger returns a new truncating method logger.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
+func NewTruncatingMethodLogger(h, m uint64) *TruncatingMethodLogger {
+	return &TruncatingMethodLogger{
 		headerMaxLen:  h,
 		messageMaxLen: m,
 
@@ -69,8 +83,10 @@
 	}
 }
 
-// Log creates a proto binary log entry, and logs it to the sink.
-func (ml *MethodLogger) Log(c LogEntryConfig) {
+// Build is an internal only method for building the proto message out of the
+// input event. It's made public to enable other library to reuse as much logic
+// in TruncatingMethodLogger as possible.
+func (ml *TruncatingMethodLogger) Build(c LogEntryConfig) *binlogpb.GrpcLogEntry {
 	m := c.toProto()
 	timestamp, _ := ptypes.TimestampProto(time.Now())
 	m.Timestamp = timestamp
@@ -78,18 +94,22 @@
 	m.SequenceIdWithinCall = ml.idWithinCallGen.next()
 
 	switch pay := m.Payload.(type) {
-	case *pb.GrpcLogEntry_ClientHeader:
+	case *binlogpb.GrpcLogEntry_ClientHeader:
 		m.PayloadTruncated = ml.truncateMetadata(pay.ClientHeader.GetMetadata())
-	case *pb.GrpcLogEntry_ServerHeader:
+	case *binlogpb.GrpcLogEntry_ServerHeader:
 		m.PayloadTruncated = ml.truncateMetadata(pay.ServerHeader.GetMetadata())
-	case *pb.GrpcLogEntry_Message:
+	case *binlogpb.GrpcLogEntry_Message:
 		m.PayloadTruncated = ml.truncateMessage(pay.Message)
 	}
-
-	ml.sink.Write(m)
+	return m
 }
 
-func (ml *MethodLogger) truncateMetadata(mdPb *pb.Metadata) (truncated bool) {
+// Log creates a proto binary log entry, and logs it to the sink.
+func (ml *TruncatingMethodLogger) Log(ctx context.Context, c LogEntryConfig) {
+	ml.sink.Write(ml.Build(c))
+}
+
+func (ml *TruncatingMethodLogger) truncateMetadata(mdPb *binlogpb.Metadata) (truncated bool) {
 	if ml.headerMaxLen == maxUInt {
 		return false
 	}
@@ -108,7 +128,7 @@
 			// but not counted towards the size limit.
 			continue
 		}
-		currentEntryLen := uint64(len(entry.Value))
+		currentEntryLen := uint64(len(entry.GetKey())) + uint64(len(entry.GetValue()))
 		if currentEntryLen > bytesLimit {
 			break
 		}
@@ -119,7 +139,7 @@
 	return truncated
 }
 
-func (ml *MethodLogger) truncateMessage(msgPb *pb.Message) (truncated bool) {
+func (ml *TruncatingMethodLogger) truncateMessage(msgPb *binlogpb.Message) (truncated bool) {
 	if ml.messageMaxLen == maxUInt {
 		return false
 	}
@@ -131,8 +151,11 @@
 }
 
 // LogEntryConfig represents the configuration for binary log entry.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
 type LogEntryConfig interface {
-	toProto() *pb.GrpcLogEntry
+	toProto() *binlogpb.GrpcLogEntry
 }
 
 // ClientHeader configs the binary log entry to be a ClientHeader entry.
@@ -146,10 +169,10 @@
 	PeerAddr net.Addr
 }
 
-func (c *ClientHeader) toProto() *pb.GrpcLogEntry {
+func (c *ClientHeader) toProto() *binlogpb.GrpcLogEntry {
 	// This function doesn't need to set all the fields (e.g. seq ID). The Log
 	// function will set the fields when necessary.
-	clientHeader := &pb.ClientHeader{
+	clientHeader := &binlogpb.ClientHeader{
 		Metadata:   mdToMetadataProto(c.Header),
 		MethodName: c.MethodName,
 		Authority:  c.Authority,
@@ -157,16 +180,16 @@
 	if c.Timeout > 0 {
 		clientHeader.Timeout = ptypes.DurationProto(c.Timeout)
 	}
-	ret := &pb.GrpcLogEntry{
-		Type: pb.GrpcLogEntry_EVENT_TYPE_CLIENT_HEADER,
-		Payload: &pb.GrpcLogEntry_ClientHeader{
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_CLIENT_HEADER,
+		Payload: &binlogpb.GrpcLogEntry_ClientHeader{
 			ClientHeader: clientHeader,
 		},
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	if c.PeerAddr != nil {
 		ret.Peer = addrToProto(c.PeerAddr)
@@ -182,19 +205,19 @@
 	PeerAddr net.Addr
 }
 
-func (c *ServerHeader) toProto() *pb.GrpcLogEntry {
-	ret := &pb.GrpcLogEntry{
-		Type: pb.GrpcLogEntry_EVENT_TYPE_SERVER_HEADER,
-		Payload: &pb.GrpcLogEntry_ServerHeader{
-			ServerHeader: &pb.ServerHeader{
+func (c *ServerHeader) toProto() *binlogpb.GrpcLogEntry {
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_SERVER_HEADER,
+		Payload: &binlogpb.GrpcLogEntry_ServerHeader{
+			ServerHeader: &binlogpb.ServerHeader{
 				Metadata: mdToMetadataProto(c.Header),
 			},
 		},
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	if c.PeerAddr != nil {
 		ret.Peer = addrToProto(c.PeerAddr)
@@ -210,7 +233,7 @@
 	Message interface{}
 }
 
-func (c *ClientMessage) toProto() *pb.GrpcLogEntry {
+func (c *ClientMessage) toProto() *binlogpb.GrpcLogEntry {
 	var (
 		data []byte
 		err  error
@@ -225,19 +248,19 @@
 	} else {
 		grpclogLogger.Infof("binarylogging: message to log is neither proto.message nor []byte")
 	}
-	ret := &pb.GrpcLogEntry{
-		Type: pb.GrpcLogEntry_EVENT_TYPE_CLIENT_MESSAGE,
-		Payload: &pb.GrpcLogEntry_Message{
-			Message: &pb.Message{
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_CLIENT_MESSAGE,
+		Payload: &binlogpb.GrpcLogEntry_Message{
+			Message: &binlogpb.Message{
 				Length: uint32(len(data)),
 				Data:   data,
 			},
 		},
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	return ret
 }
@@ -250,7 +273,7 @@
 	Message interface{}
 }
 
-func (c *ServerMessage) toProto() *pb.GrpcLogEntry {
+func (c *ServerMessage) toProto() *binlogpb.GrpcLogEntry {
 	var (
 		data []byte
 		err  error
@@ -265,19 +288,19 @@
 	} else {
 		grpclogLogger.Infof("binarylogging: message to log is neither proto.message nor []byte")
 	}
-	ret := &pb.GrpcLogEntry{
-		Type: pb.GrpcLogEntry_EVENT_TYPE_SERVER_MESSAGE,
-		Payload: &pb.GrpcLogEntry_Message{
-			Message: &pb.Message{
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_SERVER_MESSAGE,
+		Payload: &binlogpb.GrpcLogEntry_Message{
+			Message: &binlogpb.Message{
 				Length: uint32(len(data)),
 				Data:   data,
 			},
 		},
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	return ret
 }
@@ -287,15 +310,15 @@
 	OnClientSide bool
 }
 
-func (c *ClientHalfClose) toProto() *pb.GrpcLogEntry {
-	ret := &pb.GrpcLogEntry{
-		Type:    pb.GrpcLogEntry_EVENT_TYPE_CLIENT_HALF_CLOSE,
+func (c *ClientHalfClose) toProto() *binlogpb.GrpcLogEntry {
+	ret := &binlogpb.GrpcLogEntry{
+		Type:    binlogpb.GrpcLogEntry_EVENT_TYPE_CLIENT_HALF_CLOSE,
 		Payload: nil, // No payload here.
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	return ret
 }
@@ -311,7 +334,7 @@
 	PeerAddr net.Addr
 }
 
-func (c *ServerTrailer) toProto() *pb.GrpcLogEntry {
+func (c *ServerTrailer) toProto() *binlogpb.GrpcLogEntry {
 	st, ok := status.FromError(c.Err)
 	if !ok {
 		grpclogLogger.Info("binarylogging: error in trailer is not a status error")
@@ -327,10 +350,10 @@
 			grpclogLogger.Infof("binarylogging: failed to marshal status proto: %v", err)
 		}
 	}
-	ret := &pb.GrpcLogEntry{
-		Type: pb.GrpcLogEntry_EVENT_TYPE_SERVER_TRAILER,
-		Payload: &pb.GrpcLogEntry_Trailer{
-			Trailer: &pb.Trailer{
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_SERVER_TRAILER,
+		Payload: &binlogpb.GrpcLogEntry_Trailer{
+			Trailer: &binlogpb.Trailer{
 				Metadata:      mdToMetadataProto(c.Trailer),
 				StatusCode:    uint32(st.Code()),
 				StatusMessage: st.Message(),
@@ -339,9 +362,9 @@
 		},
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	if c.PeerAddr != nil {
 		ret.Peer = addrToProto(c.PeerAddr)
@@ -354,15 +377,15 @@
 	OnClientSide bool
 }
 
-func (c *Cancel) toProto() *pb.GrpcLogEntry {
-	ret := &pb.GrpcLogEntry{
-		Type:    pb.GrpcLogEntry_EVENT_TYPE_CANCEL,
+func (c *Cancel) toProto() *binlogpb.GrpcLogEntry {
+	ret := &binlogpb.GrpcLogEntry{
+		Type:    binlogpb.GrpcLogEntry_EVENT_TYPE_CANCEL,
 		Payload: nil,
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	return ret
 }
@@ -379,15 +402,15 @@
 	return strings.HasPrefix(key, "grpc-")
 }
 
-func mdToMetadataProto(md metadata.MD) *pb.Metadata {
-	ret := &pb.Metadata{}
+func mdToMetadataProto(md metadata.MD) *binlogpb.Metadata {
+	ret := &binlogpb.Metadata{}
 	for k, vv := range md {
 		if metadataKeyOmit(k) {
 			continue
 		}
 		for _, v := range vv {
 			ret.Entry = append(ret.Entry,
-				&pb.MetadataEntry{
+				&binlogpb.MetadataEntry{
 					Key:   k,
 					Value: []byte(v),
 				},
@@ -397,26 +420,26 @@
 	return ret
 }
 
-func addrToProto(addr net.Addr) *pb.Address {
-	ret := &pb.Address{}
+func addrToProto(addr net.Addr) *binlogpb.Address {
+	ret := &binlogpb.Address{}
 	switch a := addr.(type) {
 	case *net.TCPAddr:
 		if a.IP.To4() != nil {
-			ret.Type = pb.Address_TYPE_IPV4
+			ret.Type = binlogpb.Address_TYPE_IPV4
 		} else if a.IP.To16() != nil {
-			ret.Type = pb.Address_TYPE_IPV6
+			ret.Type = binlogpb.Address_TYPE_IPV6
 		} else {
-			ret.Type = pb.Address_TYPE_UNKNOWN
+			ret.Type = binlogpb.Address_TYPE_UNKNOWN
 			// Do not set address and port fields.
 			break
 		}
 		ret.Address = a.IP.String()
 		ret.IpPort = uint32(a.Port)
 	case *net.UnixAddr:
-		ret.Type = pb.Address_TYPE_UNIX
+		ret.Type = binlogpb.Address_TYPE_UNIX
 		ret.Address = a.String()
 	default:
-		ret.Type = pb.Address_TYPE_UNKNOWN
+		ret.Type = binlogpb.Address_TYPE_UNKNOWN
 	}
 	return ret
 }
diff --git a/vendor/google.golang.org/grpc/internal/binarylog/sink.go b/vendor/google.golang.org/grpc/internal/binarylog/sink.go
index c2fdd58..264de38 100644
--- a/vendor/google.golang.org/grpc/internal/binarylog/sink.go
+++ b/vendor/google.golang.org/grpc/internal/binarylog/sink.go
@@ -26,7 +26,7 @@
 	"time"
 
 	"github.com/golang/protobuf/proto"
-	pb "google.golang.org/grpc/binarylog/grpc_binarylog_v1"
+	binlogpb "google.golang.org/grpc/binarylog/grpc_binarylog_v1"
 )
 
 var (
@@ -42,15 +42,15 @@
 	// Write will be called to write the log entry into the sink.
 	//
 	// It should be thread-safe so it can be called in parallel.
-	Write(*pb.GrpcLogEntry) error
+	Write(*binlogpb.GrpcLogEntry) error
 	// Close will be called when the Sink is replaced by a new Sink.
 	Close() error
 }
 
 type noopSink struct{}
 
-func (ns *noopSink) Write(*pb.GrpcLogEntry) error { return nil }
-func (ns *noopSink) Close() error                 { return nil }
+func (ns *noopSink) Write(*binlogpb.GrpcLogEntry) error { return nil }
+func (ns *noopSink) Close() error                       { return nil }
 
 // newWriterSink creates a binary log sink with the given writer.
 //
@@ -66,7 +66,7 @@
 	out io.Writer
 }
 
-func (ws *writerSink) Write(e *pb.GrpcLogEntry) error {
+func (ws *writerSink) Write(e *binlogpb.GrpcLogEntry) error {
 	b, err := proto.Marshal(e)
 	if err != nil {
 		grpclogLogger.Errorf("binary logging: failed to marshal proto message: %v", err)
@@ -96,7 +96,7 @@
 	done        chan struct{}
 }
 
-func (fs *bufferedSink) Write(e *pb.GrpcLogEntry) error {
+func (fs *bufferedSink) Write(e *binlogpb.GrpcLogEntry) error {
 	fs.mu.Lock()
 	defer fs.mu.Unlock()
 	if !fs.flusherStarted {
diff --git a/vendor/google.golang.org/grpc/internal/buffer/unbounded.go b/vendor/google.golang.org/grpc/internal/buffer/unbounded.go
index 9f6a0c1..81c2f5f 100644
--- a/vendor/google.golang.org/grpc/internal/buffer/unbounded.go
+++ b/vendor/google.golang.org/grpc/internal/buffer/unbounded.go
@@ -35,6 +35,7 @@
 // internal/transport/transport.go for an example of this.
 type Unbounded struct {
 	c       chan interface{}
+	closed  bool
 	mu      sync.Mutex
 	backlog []interface{}
 }
@@ -47,16 +48,18 @@
 // Put adds t to the unbounded buffer.
 func (b *Unbounded) Put(t interface{}) {
 	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.closed {
+		return
+	}
 	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
@@ -64,6 +67,10 @@
 // value from the read channel.
 func (b *Unbounded) Load() {
 	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.closed {
+		return
+	}
 	if len(b.backlog) > 0 {
 		select {
 		case b.c <- b.backlog[0]:
@@ -72,7 +79,6 @@
 		default:
 		}
 	}
-	b.mu.Unlock()
 }
 
 // Get returns a read channel on which values added to the buffer, via Put(),
@@ -80,6 +86,20 @@
 //
 // 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.
+//
+// If the unbounded buffer is closed, the read channel returned by this method
+// is closed.
 func (b *Unbounded) Get() <-chan interface{} {
 	return b.c
 }
+
+// Close closes the unbounded buffer.
+func (b *Unbounded) Close() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.closed {
+		return
+	}
+	b.closed = true
+	close(b.c)
+}
diff --git a/vendor/google.golang.org/grpc/internal/channelz/funcs.go b/vendor/google.golang.org/grpc/internal/channelz/funcs.go
index cd18075..777cbcd 100644
--- a/vendor/google.golang.org/grpc/internal/channelz/funcs.go
+++ b/vendor/google.golang.org/grpc/internal/channelz/funcs.go
@@ -24,6 +24,8 @@
 package channelz
 
 import (
+	"context"
+	"errors"
 	"fmt"
 	"sort"
 	"sync"
@@ -49,7 +51,8 @@
 // TurnOn turns on channelz data collection.
 func TurnOn() {
 	if !IsOn() {
-		NewChannelzStorage()
+		db.set(newChannelMap())
+		idGen.reset()
 		atomic.StoreInt32(&curState, 1)
 	}
 }
@@ -94,46 +97,40 @@
 	return d.DB
 }
 
-// NewChannelzStorage initializes channelz data storage and id generator.
+// NewChannelzStorageForTesting initializes channelz data storage and id
+// generator for testing purposes.
 //
-// This function returns a cleanup function to wait for all channelz state to be reset by the
-// grpc goroutines when those entities get closed. By using this cleanup function, we make sure tests
-// don't mess up each other, i.e. lingering goroutine from previous test doing entity removal happen
-// to remove some entity just register by the new test, since the id space is the same.
-//
-// Note: This function is exported for testing purpose only. User should not call
-// it in most cases.
-func NewChannelzStorage() (cleanup func() error) {
-	db.set(&channelMap{
-		topLevelChannels: make(map[int64]struct{}),
-		channels:         make(map[int64]*channel),
-		listenSockets:    make(map[int64]*listenSocket),
-		normalSockets:    make(map[int64]*normalSocket),
-		servers:          make(map[int64]*server),
-		subChannels:      make(map[int64]*subChannel),
-	})
+// Returns a cleanup function to be invoked by the test, which waits for up to
+// 10s for all channelz state to be reset by the grpc goroutines when those
+// entities get closed. This cleanup function helps with ensuring that tests
+// don't mess up each other.
+func NewChannelzStorageForTesting() (cleanup func() error) {
+	db.set(newChannelMap())
 	idGen.reset()
+
 	return func() error {
-		var err error
 		cm := db.get()
 		if cm == nil {
 			return nil
 		}
-		for i := 0; i < 1000; i++ {
-			cm.mu.Lock()
-			if len(cm.topLevelChannels) == 0 && len(cm.servers) == 0 && len(cm.channels) == 0 && len(cm.subChannels) == 0 && len(cm.listenSockets) == 0 && len(cm.normalSockets) == 0 {
-				cm.mu.Unlock()
-				// all things stored in the channelz map have been cleared.
+
+		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+		defer cancel()
+		ticker := time.NewTicker(10 * time.Millisecond)
+		defer ticker.Stop()
+		for {
+			cm.mu.RLock()
+			topLevelChannels, servers, channels, subChannels, listenSockets, normalSockets := len(cm.topLevelChannels), len(cm.servers), len(cm.channels), len(cm.subChannels), len(cm.listenSockets), len(cm.normalSockets)
+			cm.mu.RUnlock()
+
+			if err := ctx.Err(); err != nil {
+				return fmt.Errorf("after 10s the channelz map has not been cleaned up yet, topchannels: %d, servers: %d, channels: %d, subchannels: %d, listen sockets: %d, normal sockets: %d", topLevelChannels, servers, channels, subChannels, listenSockets, normalSockets)
+			}
+			if topLevelChannels == 0 && servers == 0 && channels == 0 && subChannels == 0 && listenSockets == 0 && normalSockets == 0 {
 				return nil
 			}
-			cm.mu.Unlock()
-			time.Sleep(10 * time.Millisecond)
+			<-ticker.C
 		}
-
-		cm.mu.Lock()
-		err = fmt.Errorf("after 10s the channelz map has not been cleaned up yet, topchannels: %d, servers: %d, channels: %d, subchannels: %d, listen sockets: %d, normal sockets: %d", len(cm.topLevelChannels), len(cm.servers), len(cm.channels), len(cm.subChannels), len(cm.listenSockets), len(cm.normalSockets))
-		cm.mu.Unlock()
-		return err
 	}
 }
 
@@ -188,54 +185,77 @@
 	return db.get().GetServer(id)
 }
 
-// RegisterChannel registers the given channel c in channelz database with ref
-// as its reference name, and add it to the child list of its parent (identified
-// by pid). pid = 0 means no parent. It returns the unique channelz tracking id
-// assigned to this channel.
-func RegisterChannel(c Channel, pid int64, ref string) int64 {
+// RegisterChannel registers the given channel c in the channelz database with
+// ref as its reference name, and adds it to the child list of its parent
+// (identified by pid). pid == nil means no parent.
+//
+// Returns a unique channelz identifier assigned to this channel.
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterChannel(c Channel, pid *Identifier, ref string) *Identifier {
 	id := idGen.genID()
+	var parent int64
+	isTopChannel := true
+	if pid != nil {
+		isTopChannel = false
+		parent = pid.Int()
+	}
+
+	if !IsOn() {
+		return newIdentifer(RefChannel, id, pid)
+	}
+
 	cn := &channel{
 		refName:     ref,
 		c:           c,
 		subChans:    make(map[int64]string),
 		nestedChans: make(map[int64]string),
 		id:          id,
-		pid:         pid,
+		pid:         parent,
 		trace:       &channelTrace{createdTime: time.Now(), events: make([]*TraceEvent, 0, getMaxTraceEntry())},
 	}
-	if pid == 0 {
-		db.get().addChannel(id, cn, true, pid)
-	} else {
-		db.get().addChannel(id, cn, false, pid)
-	}
-	return id
+	db.get().addChannel(id, cn, isTopChannel, parent)
+	return newIdentifer(RefChannel, id, pid)
 }
 
-// RegisterSubChannel registers the given channel c in channelz database with ref
-// as its reference name, and add it to the child list of its parent (identified
-// 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 {
-		logger.Error("a SubChannel's parent id cannot be 0")
-		return 0
+// RegisterSubChannel registers the given subChannel c in the channelz database
+// with ref as its reference name, and adds it to the child list of its parent
+// (identified by pid).
+//
+// Returns a unique channelz identifier assigned to this subChannel.
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterSubChannel(c Channel, pid *Identifier, ref string) (*Identifier, error) {
+	if pid == nil {
+		return nil, errors.New("a SubChannel's parent id cannot be nil")
 	}
 	id := idGen.genID()
+	if !IsOn() {
+		return newIdentifer(RefSubChannel, id, pid), nil
+	}
+
 	sc := &subChannel{
 		refName: ref,
 		c:       c,
 		sockets: make(map[int64]string),
 		id:      id,
-		pid:     pid,
+		pid:     pid.Int(),
 		trace:   &channelTrace{createdTime: time.Now(), events: make([]*TraceEvent, 0, getMaxTraceEntry())},
 	}
-	db.get().addSubChannel(id, sc, pid)
-	return id
+	db.get().addSubChannel(id, sc, pid.Int())
+	return newIdentifer(RefSubChannel, id, pid), nil
 }
 
 // RegisterServer registers the given server s in channelz database. It returns
 // the unique channelz tracking id assigned to this server.
-func RegisterServer(s Server, ref string) int64 {
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterServer(s Server, ref string) *Identifier {
 	id := idGen.genID()
+	if !IsOn() {
+		return newIdentifer(RefServer, id, nil)
+	}
+
 	svr := &server{
 		refName:       ref,
 		s:             s,
@@ -244,71 +264,92 @@
 		id:            id,
 	}
 	db.get().addServer(id, svr)
-	return id
+	return newIdentifer(RefServer, id, nil)
 }
 
 // RegisterListenSocket registers the given listen socket s in channelz database
 // with ref as its reference name, and add it to the child list of its parent
 // (identified by pid). It returns the unique channelz tracking id assigned to
 // this listen socket.
-func RegisterListenSocket(s Socket, pid int64, ref string) int64 {
-	if pid == 0 {
-		logger.Error("a ListenSocket's parent id cannot be 0")
-		return 0
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterListenSocket(s Socket, pid *Identifier, ref string) (*Identifier, error) {
+	if pid == nil {
+		return nil, errors.New("a ListenSocket's parent id cannot be 0")
 	}
 	id := idGen.genID()
-	ls := &listenSocket{refName: ref, s: s, id: id, pid: pid}
-	db.get().addListenSocket(id, ls, pid)
-	return id
+	if !IsOn() {
+		return newIdentifer(RefListenSocket, id, pid), nil
+	}
+
+	ls := &listenSocket{refName: ref, s: s, id: id, pid: pid.Int()}
+	db.get().addListenSocket(id, ls, pid.Int())
+	return newIdentifer(RefListenSocket, id, pid), nil
 }
 
 // RegisterNormalSocket registers the given normal socket s in channelz database
-// with ref as its reference name, and add it to the child list of its parent
+// with ref as its reference name, and adds it to the child list of its parent
 // (identified by pid). It returns the unique channelz tracking id assigned to
 // this normal socket.
-func RegisterNormalSocket(s Socket, pid int64, ref string) int64 {
-	if pid == 0 {
-		logger.Error("a NormalSocket's parent id cannot be 0")
-		return 0
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterNormalSocket(s Socket, pid *Identifier, ref string) (*Identifier, error) {
+	if pid == nil {
+		return nil, errors.New("a NormalSocket's parent id cannot be 0")
 	}
 	id := idGen.genID()
-	ns := &normalSocket{refName: ref, s: s, id: id, pid: pid}
-	db.get().addNormalSocket(id, ns, pid)
-	return id
+	if !IsOn() {
+		return newIdentifer(RefNormalSocket, id, pid), nil
+	}
+
+	ns := &normalSocket{refName: ref, s: s, id: id, pid: pid.Int()}
+	db.get().addNormalSocket(id, ns, pid.Int())
+	return newIdentifer(RefNormalSocket, id, pid), nil
 }
 
 // RemoveEntry removes an entry with unique channelz tracking id to be id from
 // channelz database.
-func RemoveEntry(id int64) {
-	db.get().removeEntry(id)
+//
+// If channelz is not turned ON, this function is a no-op.
+func RemoveEntry(id *Identifier) {
+	if !IsOn() {
+		return
+	}
+	db.get().removeEntry(id.Int())
 }
 
-// TraceEventDesc is what the caller of AddTraceEvent should provide to describe the event to be added
-// to the channel trace.
-// The Parent field is optional. It is used for event that will be recorded in the entity's parent
-// trace also.
+// TraceEventDesc is what the caller of AddTraceEvent should provide to describe
+// the event to be added to the channel trace.
+//
+// The Parent field is optional. It is used for an event that will be recorded
+// in the entity's parent trace.
 type TraceEventDesc struct {
 	Desc     string
 	Severity Severity
 	Parent   *TraceEventDesc
 }
 
-// AddTraceEvent adds trace related to the entity with specified id, using the provided TraceEventDesc.
-func AddTraceEvent(l grpclog.DepthLoggerV2, id int64, depth int, desc *TraceEventDesc) {
-	for d := desc; d != nil; d = d.Parent {
-		switch d.Severity {
-		case CtUnknown, CtInfo:
-			l.InfoDepth(depth+1, d.Desc)
-		case CtWarning:
-			l.WarningDepth(depth+1, d.Desc)
-		case CtError:
-			l.ErrorDepth(depth+1, d.Desc)
-		}
+// AddTraceEvent adds trace related to the entity with specified id, using the
+// provided TraceEventDesc.
+//
+// If channelz is not turned ON, this will simply log the event descriptions.
+func AddTraceEvent(l grpclog.DepthLoggerV2, id *Identifier, depth int, desc *TraceEventDesc) {
+	// Log only the trace description associated with the bottom most entity.
+	switch desc.Severity {
+	case CtUnknown, CtInfo:
+		l.InfoDepth(depth+1, withParens(id)+desc.Desc)
+	case CtWarning:
+		l.WarningDepth(depth+1, withParens(id)+desc.Desc)
+	case CtError:
+		l.ErrorDepth(depth+1, withParens(id)+desc.Desc)
 	}
+
 	if getMaxTraceEntry() == 0 {
 		return
 	}
-	db.get().traceEvent(id, desc)
+	if IsOn() {
+		db.get().traceEvent(id.Int(), desc)
+	}
 }
 
 // channelMap is the storage data structure for channelz.
@@ -326,6 +367,17 @@
 	normalSockets    map[int64]*normalSocket
 }
 
+func newChannelMap() *channelMap {
+	return &channelMap{
+		topLevelChannels: make(map[int64]struct{}),
+		channels:         make(map[int64]*channel),
+		listenSockets:    make(map[int64]*listenSocket),
+		normalSockets:    make(map[int64]*normalSocket),
+		servers:          make(map[int64]*server),
+		subChannels:      make(map[int64]*subChannel),
+	}
+}
+
 func (c *channelMap) addServer(id int64, s *server) {
 	c.mu.Lock()
 	s.cm = c
diff --git a/vendor/google.golang.org/grpc/internal/channelz/id.go b/vendor/google.golang.org/grpc/internal/channelz/id.go
new file mode 100644
index 0000000..c9a27ac
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/channelz/id.go
@@ -0,0 +1,75 @@
+/*
+ *
+ * Copyright 2022 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"
+
+// Identifier is an opaque identifier which uniquely identifies an entity in the
+// channelz database.
+type Identifier struct {
+	typ RefChannelType
+	id  int64
+	str string
+	pid *Identifier
+}
+
+// Type returns the entity type corresponding to id.
+func (id *Identifier) Type() RefChannelType {
+	return id.typ
+}
+
+// Int returns the integer identifier corresponding to id.
+func (id *Identifier) Int() int64 {
+	return id.id
+}
+
+// String returns a string representation of the entity corresponding to id.
+//
+// This includes some information about the parent as well. Examples:
+// Top-level channel: [Channel #channel-number]
+// Nested channel:    [Channel #parent-channel-number Channel #channel-number]
+// Sub channel:       [Channel #parent-channel SubChannel #subchannel-number]
+func (id *Identifier) String() string {
+	return id.str
+}
+
+// Equal returns true if other is the same as id.
+func (id *Identifier) Equal(other *Identifier) bool {
+	if (id != nil) != (other != nil) {
+		return false
+	}
+	if id == nil && other == nil {
+		return true
+	}
+	return id.typ == other.typ && id.id == other.id && id.pid == other.pid
+}
+
+// NewIdentifierForTesting returns a new opaque identifier to be used only for
+// testing purposes.
+func NewIdentifierForTesting(typ RefChannelType, id int64, pid *Identifier) *Identifier {
+	return newIdentifer(typ, id, pid)
+}
+
+func newIdentifer(typ RefChannelType, id int64, pid *Identifier) *Identifier {
+	str := fmt.Sprintf("%s #%d", typ, id)
+	if pid != nil {
+		str = fmt.Sprintf("%s %s", pid, str)
+	}
+	return &Identifier{typ: typ, id: id, str: str, pid: pid}
+}
diff --git a/vendor/google.golang.org/grpc/internal/channelz/logging.go b/vendor/google.golang.org/grpc/internal/channelz/logging.go
index b0013f9..8e13a3d 100644
--- a/vendor/google.golang.org/grpc/internal/channelz/logging.go
+++ b/vendor/google.golang.org/grpc/internal/channelz/logging.go
@@ -26,77 +26,54 @@
 
 var logger = grpclog.Component("channelz")
 
+func withParens(id *Identifier) string {
+	return "[" + id.String() + "] "
+}
+
 // Info logs and adds a trace event if channelz is on.
-func Info(l grpclog.DepthLoggerV2, id int64, args ...interface{}) {
-	if IsOn() {
-		AddTraceEvent(l, id, 1, &TraceEventDesc{
-			Desc:     fmt.Sprint(args...),
-			Severity: CtInfo,
-		})
-	} else {
-		l.InfoDepth(1, args...)
-	}
+func Info(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprint(args...),
+		Severity: CtInfo,
+	})
 }
 
 // Infof logs and adds a trace event if channelz is on.
-func Infof(l grpclog.DepthLoggerV2, id int64, format string, args ...interface{}) {
-	msg := fmt.Sprintf(format, args...)
-	if IsOn() {
-		AddTraceEvent(l, id, 1, &TraceEventDesc{
-			Desc:     msg,
-			Severity: CtInfo,
-		})
-	} else {
-		l.InfoDepth(1, msg)
-	}
+func Infof(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprintf(format, args...),
+		Severity: CtInfo,
+	})
 }
 
 // Warning logs and adds a trace event if channelz is on.
-func Warning(l grpclog.DepthLoggerV2, id int64, args ...interface{}) {
-	if IsOn() {
-		AddTraceEvent(l, id, 1, &TraceEventDesc{
-			Desc:     fmt.Sprint(args...),
-			Severity: CtWarning,
-		})
-	} else {
-		l.WarningDepth(1, args...)
-	}
+func Warning(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprint(args...),
+		Severity: CtWarning,
+	})
 }
 
 // Warningf logs and adds a trace event if channelz is on.
-func Warningf(l grpclog.DepthLoggerV2, id int64, format string, args ...interface{}) {
-	msg := fmt.Sprintf(format, args...)
-	if IsOn() {
-		AddTraceEvent(l, id, 1, &TraceEventDesc{
-			Desc:     msg,
-			Severity: CtWarning,
-		})
-	} else {
-		l.WarningDepth(1, msg)
-	}
+func Warningf(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprintf(format, args...),
+		Severity: CtWarning,
+	})
 }
 
 // Error logs and adds a trace event if channelz is on.
-func Error(l grpclog.DepthLoggerV2, id int64, args ...interface{}) {
-	if IsOn() {
-		AddTraceEvent(l, id, 1, &TraceEventDesc{
-			Desc:     fmt.Sprint(args...),
-			Severity: CtError,
-		})
-	} else {
-		l.ErrorDepth(1, args...)
-	}
+func Error(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprint(args...),
+		Severity: CtError,
+	})
 }
 
 // Errorf logs and adds a trace event if channelz is on.
-func Errorf(l grpclog.DepthLoggerV2, id int64, format string, args ...interface{}) {
-	msg := fmt.Sprintf(format, args...)
-	if IsOn() {
-		AddTraceEvent(l, id, 1, &TraceEventDesc{
-			Desc:     msg,
-			Severity: CtError,
-		})
-	} else {
-		l.ErrorDepth(1, msg)
-	}
+func Errorf(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprintf(format, args...),
+		Severity: CtError,
+	})
 }
diff --git a/vendor/google.golang.org/grpc/internal/channelz/types.go b/vendor/google.golang.org/grpc/internal/channelz/types.go
index 0b541d2..7b2f350 100644
--- a/vendor/google.golang.org/grpc/internal/channelz/types.go
+++ b/vendor/google.golang.org/grpc/internal/channelz/types.go
@@ -686,12 +686,33 @@
 type RefChannelType int
 
 const (
+	// RefUnknown indicates an unknown entity type, the zero value for this type.
+	RefUnknown RefChannelType = iota
 	// RefChannel indicates the referenced entity is a Channel.
-	RefChannel RefChannelType = iota
+	RefChannel
 	// RefSubChannel indicates the referenced entity is a SubChannel.
 	RefSubChannel
+	// RefServer indicates the referenced entity is a Server.
+	RefServer
+	// RefListenSocket indicates the referenced entity is a ListenSocket.
+	RefListenSocket
+	// RefNormalSocket indicates the referenced entity is a NormalSocket.
+	RefNormalSocket
 )
 
+var refChannelTypeToString = map[RefChannelType]string{
+	RefUnknown:      "Unknown",
+	RefChannel:      "Channel",
+	RefSubChannel:   "SubChannel",
+	RefServer:       "Server",
+	RefListenSocket: "ListenSocket",
+	RefNormalSocket: "NormalSocket",
+}
+
+func (r RefChannelType) String() string {
+	return refChannelTypeToString[r]
+}
+
 func (c *channelTrace) dumpData() *ChannelTrace {
 	c.mu.Lock()
 	ct := &ChannelTrace{EventNum: c.eventCount, CreationTime: c.createdTime}
diff --git a/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go b/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go
index 6f02725..80fd5c7 100644
--- a/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go
+++ b/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go
@@ -21,15 +21,46 @@
 
 import (
 	"os"
+	"strconv"
 	"strings"
 )
 
-const (
-	prefix          = "GRPC_GO_"
-	txtErrIgnoreStr = prefix + "IGNORE_TXT_ERRORS"
-)
-
 var (
 	// TXTErrIgnore is set if TXT errors should be ignored ("GRPC_GO_IGNORE_TXT_ERRORS" is not "false").
-	TXTErrIgnore = !strings.EqualFold(os.Getenv(txtErrIgnoreStr), "false")
+	TXTErrIgnore = boolFromEnv("GRPC_GO_IGNORE_TXT_ERRORS", true)
+	// AdvertiseCompressors is set if registered compressor should be advertised
+	// ("GRPC_GO_ADVERTISE_COMPRESSORS" is not "false").
+	AdvertiseCompressors = boolFromEnv("GRPC_GO_ADVERTISE_COMPRESSORS", true)
+	// RingHashCap indicates the maximum ring size which defaults to 4096
+	// entries but may be overridden by setting the environment variable
+	// "GRPC_RING_HASH_CAP".  This does not override the default bounds
+	// checking which NACKs configs specifying ring sizes > 8*1024*1024 (~8M).
+	RingHashCap = uint64FromEnv("GRPC_RING_HASH_CAP", 4096, 1, 8*1024*1024)
+	// PickFirstLBConfig is set if we should support configuration of the
+	// pick_first LB policy, which can be enabled by setting the environment
+	// variable "GRPC_EXPERIMENTAL_PICKFIRST_LB_CONFIG" to "true".
+	PickFirstLBConfig = boolFromEnv("GRPC_EXPERIMENTAL_PICKFIRST_LB_CONFIG", false)
 )
+
+func boolFromEnv(envVar string, def bool) bool {
+	if def {
+		// The default is true; return true unless the variable is "false".
+		return !strings.EqualFold(os.Getenv(envVar), "false")
+	}
+	// The default is false; return false unless the variable is "true".
+	return strings.EqualFold(os.Getenv(envVar), "true")
+}
+
+func uint64FromEnv(envVar string, def, min, max uint64) uint64 {
+	v, err := strconv.ParseUint(os.Getenv(envVar), 10, 64)
+	if err != nil {
+		return def
+	}
+	if v < min {
+		return min
+	}
+	if v > max {
+		return max
+	}
+	return v
+}
diff --git a/vendor/google.golang.org/grpc/internal/envconfig/observability.go b/vendor/google.golang.org/grpc/internal/envconfig/observability.go
new file mode 100644
index 0000000..dd314cf
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/envconfig/observability.go
@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2022 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 envconfig
+
+import "os"
+
+const (
+	envObservabilityConfig     = "GRPC_GCP_OBSERVABILITY_CONFIG"
+	envObservabilityConfigFile = "GRPC_GCP_OBSERVABILITY_CONFIG_FILE"
+)
+
+var (
+	// ObservabilityConfig is the json configuration for the gcp/observability
+	// package specified directly in the envObservabilityConfig env var.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	ObservabilityConfig = os.Getenv(envObservabilityConfig)
+	// ObservabilityConfigFile is the json configuration for the
+	// gcp/observability specified in a file with the location specified in
+	// envObservabilityConfigFile env var.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	ObservabilityConfigFile = os.Getenv(envObservabilityConfigFile)
+)
diff --git a/vendor/google.golang.org/grpc/internal/envconfig/xds.go b/vendor/google.golang.org/grpc/internal/envconfig/xds.go
index 9bad03c..02b4b6a 100644
--- a/vendor/google.golang.org/grpc/internal/envconfig/xds.go
+++ b/vendor/google.golang.org/grpc/internal/envconfig/xds.go
@@ -20,31 +20,21 @@
 
 import (
 	"os"
-	"strings"
 )
 
 const (
 	// XDSBootstrapFileNameEnv is the env variable to set bootstrap file name.
 	// Do not use this and read from env directly. Its value is read and kept in
-	// variable BootstrapFileName.
+	// variable XDSBootstrapFileName.
 	//
 	// When both bootstrap FileName and FileContent are set, FileName is used.
 	XDSBootstrapFileNameEnv = "GRPC_XDS_BOOTSTRAP"
-	// XDSBootstrapFileContentEnv is the env variable to set bootstrapp file
+	// XDSBootstrapFileContentEnv is the env variable to set bootstrap file
 	// content. Do not use this and read from env directly. Its value is read
-	// and kept in variable BootstrapFileName.
+	// and kept in variable XDSBootstrapFileContent.
 	//
 	// When both bootstrap FileName and FileContent are set, FileName is used.
 	XDSBootstrapFileContentEnv = "GRPC_XDS_BOOTSTRAP_CONFIG"
-
-	ringHashSupportEnv           = "GRPC_XDS_EXPERIMENTAL_ENABLE_RING_HASH"
-	clientSideSecuritySupportEnv = "GRPC_XDS_EXPERIMENTAL_SECURITY_SUPPORT"
-	aggregateAndDNSSupportEnv    = "GRPC_XDS_EXPERIMENTAL_ENABLE_AGGREGATE_AND_LOGICAL_DNS_CLUSTER"
-	rbacSupportEnv               = "GRPC_XDS_EXPERIMENTAL_RBAC"
-	federationEnv                = "GRPC_EXPERIMENTAL_XDS_FEDERATION"
-	rlsInXDSEnv                  = "GRPC_EXPERIMENTAL_XDS_RLS_LB"
-
-	c2pResolverTestOnlyTrafficDirectorURIEnv = "GRPC_TEST_ONLY_GOOGLE_C2P_RESOLVER_TRAFFIC_DIRECTOR_URI"
 )
 
 var (
@@ -63,35 +53,43 @@
 	// XDSRingHash indicates whether ring hash support is enabled, which can be
 	// disabled by setting the environment variable
 	// "GRPC_XDS_EXPERIMENTAL_ENABLE_RING_HASH" to "false".
-	XDSRingHash = !strings.EqualFold(os.Getenv(ringHashSupportEnv), "false")
+	XDSRingHash = boolFromEnv("GRPC_XDS_EXPERIMENTAL_ENABLE_RING_HASH", true)
 	// XDSClientSideSecurity is used to control processing of security
 	// configuration on the client-side.
 	//
 	// Note that there is no env var protection for the server-side because we
 	// have a brand new API on the server-side and users explicitly need to use
 	// the new API to get security integration on the server.
-	XDSClientSideSecurity = !strings.EqualFold(os.Getenv(clientSideSecuritySupportEnv), "false")
-	// XDSAggregateAndDNS indicates whether processing of aggregated cluster
-	// and DNS cluster is enabled, which can be enabled by setting the
-	// environment variable
-	// "GRPC_XDS_EXPERIMENTAL_ENABLE_AGGREGATE_AND_LOGICAL_DNS_CLUSTER" to
-	// "true".
-	XDSAggregateAndDNS = strings.EqualFold(os.Getenv(aggregateAndDNSSupportEnv), "true")
+	XDSClientSideSecurity = boolFromEnv("GRPC_XDS_EXPERIMENTAL_SECURITY_SUPPORT", true)
+	// XDSAggregateAndDNS indicates whether processing of aggregated cluster and
+	// DNS cluster is enabled, which can be disabled by setting the environment
+	// variable "GRPC_XDS_EXPERIMENTAL_ENABLE_AGGREGATE_AND_LOGICAL_DNS_CLUSTER"
+	// to "false".
+	XDSAggregateAndDNS = boolFromEnv("GRPC_XDS_EXPERIMENTAL_ENABLE_AGGREGATE_AND_LOGICAL_DNS_CLUSTER", true)
 
 	// XDSRBAC indicates whether xDS configured RBAC HTTP Filter is enabled,
 	// which can be disabled by setting the environment variable
 	// "GRPC_XDS_EXPERIMENTAL_RBAC" to "false".
-	XDSRBAC = !strings.EqualFold(os.Getenv(rbacSupportEnv), "false")
-
-	// XDSFederation indicates whether federation support is enabled.
-	XDSFederation = strings.EqualFold(os.Getenv(federationEnv), "true")
+	XDSRBAC = boolFromEnv("GRPC_XDS_EXPERIMENTAL_RBAC", true)
+	// XDSOutlierDetection indicates whether outlier detection support is
+	// enabled, which can be disabled by setting the environment variable
+	// "GRPC_EXPERIMENTAL_ENABLE_OUTLIER_DETECTION" to "false".
+	XDSOutlierDetection = boolFromEnv("GRPC_EXPERIMENTAL_ENABLE_OUTLIER_DETECTION", true)
+	// XDSFederation indicates whether federation support is enabled, which can
+	// be enabled by setting the environment variable
+	// "GRPC_EXPERIMENTAL_XDS_FEDERATION" to "true".
+	XDSFederation = boolFromEnv("GRPC_EXPERIMENTAL_XDS_FEDERATION", true)
 
 	// XDSRLS indicates whether processing of Cluster Specifier plugins and
-	// support for the RLS CLuster Specifier is enabled, which can be enabled by
+	// support for the RLS CLuster Specifier is enabled, which can be disabled by
 	// setting the environment variable "GRPC_EXPERIMENTAL_XDS_RLS_LB" to
-	// "true".
-	XDSRLS = strings.EqualFold(os.Getenv(rlsInXDSEnv), "true")
+	// "false".
+	XDSRLS = boolFromEnv("GRPC_EXPERIMENTAL_XDS_RLS_LB", true)
 
 	// C2PResolverTestOnlyTrafficDirectorURI is the TD URI for testing.
-	C2PResolverTestOnlyTrafficDirectorURI = os.Getenv(c2pResolverTestOnlyTrafficDirectorURIEnv)
+	C2PResolverTestOnlyTrafficDirectorURI = os.Getenv("GRPC_TEST_ONLY_GOOGLE_C2P_RESOLVER_TRAFFIC_DIRECTOR_URI")
+	// XDSCustomLBPolicy indicates whether Custom LB Policies are enabled, which
+	// can be disabled by setting the environment variable
+	// "GRPC_EXPERIMENTAL_XDS_CUSTOM_LB_CONFIG" to "false".
+	XDSCustomLBPolicy = boolFromEnv("GRPC_EXPERIMENTAL_XDS_CUSTOM_LB_CONFIG", true)
 )
diff --git a/vendor/google.golang.org/grpc/internal/grpclog/prefixLogger.go b/vendor/google.golang.org/grpc/internal/grpclog/prefixLogger.go
index 82af70e..02224b4 100644
--- a/vendor/google.golang.org/grpc/internal/grpclog/prefixLogger.go
+++ b/vendor/google.golang.org/grpc/internal/grpclog/prefixLogger.go
@@ -63,6 +63,9 @@
 
 // Debugf does info logging at verbose level 2.
 func (pl *PrefixLogger) Debugf(format string, args ...interface{}) {
+	// TODO(6044): Refactor interfaces LoggerV2 and DepthLogger, and maybe
+	// rewrite PrefixLogger a little to ensure that we don't use the global
+	// `Logger` here, and instead use the `logger` field.
 	if !Logger.V(2) {
 		return
 	}
@@ -73,6 +76,15 @@
 		return
 	}
 	InfoDepth(1, fmt.Sprintf(format, args...))
+
+}
+
+// V reports whether verbosity level l is at least the requested verbose level.
+func (pl *PrefixLogger) V(l int) bool {
+	// TODO(6044): Refactor interfaces LoggerV2 and DepthLogger, and maybe
+	// rewrite PrefixLogger a little to ensure that we don't use the global
+	// `Logger` here, and instead use the `logger` field.
+	return Logger.V(l)
 }
 
 // NewPrefixLogger creates a prefix logger with the given prefix.
diff --git a/vendor/google.golang.org/grpc/internal/grpcrand/grpcrand.go b/vendor/google.golang.org/grpc/internal/grpcrand/grpcrand.go
index 740f83c..d08e3e9 100644
--- a/vendor/google.golang.org/grpc/internal/grpcrand/grpcrand.go
+++ b/vendor/google.golang.org/grpc/internal/grpcrand/grpcrand.go
@@ -52,6 +52,13 @@
 	return r.Intn(n)
 }
 
+// Int31n implements rand.Int31n on the grpcrand global source.
+func Int31n(n int32) int32 {
+	mu.Lock()
+	defer mu.Unlock()
+	return r.Int31n(n)
+}
+
 // Float64 implements rand.Float64 on the grpcrand global source.
 func Float64() float64 {
 	mu.Lock()
@@ -65,3 +72,17 @@
 	defer mu.Unlock()
 	return r.Uint64()
 }
+
+// Uint32 implements rand.Uint32 on the grpcrand global source.
+func Uint32() uint32 {
+	mu.Lock()
+	defer mu.Unlock()
+	return r.Uint32()
+}
+
+// Shuffle implements rand.Shuffle on the grpcrand global source.
+var Shuffle = func(n int, f func(int, int)) {
+	mu.Lock()
+	defer mu.Unlock()
+	r.Shuffle(n, f)
+}
diff --git a/vendor/google.golang.org/grpc/internal/grpcsync/callback_serializer.go b/vendor/google.golang.org/grpc/internal/grpcsync/callback_serializer.go
new file mode 100644
index 0000000..37b8d41
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/grpcsync/callback_serializer.go
@@ -0,0 +1,119 @@
+/*
+ *
+ * Copyright 2022 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 grpcsync
+
+import (
+	"context"
+	"sync"
+
+	"google.golang.org/grpc/internal/buffer"
+)
+
+// CallbackSerializer provides a mechanism to schedule callbacks in a
+// synchronized manner. It provides a FIFO guarantee on the order of execution
+// of scheduled callbacks. New callbacks can be scheduled by invoking the
+// Schedule() method.
+//
+// This type is safe for concurrent access.
+type CallbackSerializer struct {
+	// Done is closed once the serializer is shut down completely, i.e all
+	// scheduled callbacks are executed and the serializer has deallocated all
+	// its resources.
+	Done chan struct{}
+
+	callbacks *buffer.Unbounded
+	closedMu  sync.Mutex
+	closed    bool
+}
+
+// NewCallbackSerializer returns a new CallbackSerializer instance. The provided
+// context will be passed to the scheduled callbacks. Users should cancel the
+// provided context to shutdown the CallbackSerializer. It is guaranteed that no
+// callbacks will be added once this context is canceled, and any pending un-run
+// callbacks will be executed before the serializer is shut down.
+func NewCallbackSerializer(ctx context.Context) *CallbackSerializer {
+	t := &CallbackSerializer{
+		Done:      make(chan struct{}),
+		callbacks: buffer.NewUnbounded(),
+	}
+	go t.run(ctx)
+	return t
+}
+
+// Schedule adds a callback to be scheduled after existing callbacks are run.
+//
+// Callbacks are expected to honor the context when performing any blocking
+// operations, and should return early when the context is canceled.
+//
+// Return value indicates if the callback was successfully added to the list of
+// callbacks to be executed by the serializer. It is not possible to add
+// callbacks once the context passed to NewCallbackSerializer is cancelled.
+func (t *CallbackSerializer) Schedule(f func(ctx context.Context)) bool {
+	t.closedMu.Lock()
+	defer t.closedMu.Unlock()
+
+	if t.closed {
+		return false
+	}
+	t.callbacks.Put(f)
+	return true
+}
+
+func (t *CallbackSerializer) run(ctx context.Context) {
+	var backlog []func(context.Context)
+
+	defer close(t.Done)
+	for ctx.Err() == nil {
+		select {
+		case <-ctx.Done():
+			// Do nothing here. Next iteration of the for loop will not happen,
+			// since ctx.Err() would be non-nil.
+		case callback, ok := <-t.callbacks.Get():
+			if !ok {
+				return
+			}
+			t.callbacks.Load()
+			callback.(func(ctx context.Context))(ctx)
+		}
+	}
+
+	// Fetch pending callbacks if any, and execute them before returning from
+	// this method and closing t.Done.
+	t.closedMu.Lock()
+	t.closed = true
+	backlog = t.fetchPendingCallbacks()
+	t.callbacks.Close()
+	t.closedMu.Unlock()
+	for _, b := range backlog {
+		b(ctx)
+	}
+}
+
+func (t *CallbackSerializer) fetchPendingCallbacks() []func(context.Context) {
+	var backlog []func(context.Context)
+	for {
+		select {
+		case b := <-t.callbacks.Get():
+			backlog = append(backlog, b.(func(context.Context)))
+			t.callbacks.Load()
+		default:
+			return backlog
+		}
+	}
+}
diff --git a/vendor/google.golang.org/grpc/internal/grpcsync/oncefunc.go b/vendor/google.golang.org/grpc/internal/grpcsync/oncefunc.go
new file mode 100644
index 0000000..6635f7b
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/grpcsync/oncefunc.go
@@ -0,0 +1,32 @@
+/*
+ *
+ * Copyright 2022 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 grpcsync
+
+import (
+	"sync"
+)
+
+// OnceFunc returns a function wrapping f which ensures f is only executed
+// once even if the returned function is executed multiple times.
+func OnceFunc(f func()) func() {
+	var once sync.Once
+	return func() {
+		once.Do(f)
+	}
+}
diff --git a/vendor/google.golang.org/grpc/internal/grpcutil/compressor.go b/vendor/google.golang.org/grpc/internal/grpcutil/compressor.go
new file mode 100644
index 0000000..9f40909
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/grpcutil/compressor.go
@@ -0,0 +1,47 @@
+/*
+ *
+ * Copyright 2022 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
+
+import (
+	"strings"
+
+	"google.golang.org/grpc/internal/envconfig"
+)
+
+// RegisteredCompressorNames holds names of the registered compressors.
+var RegisteredCompressorNames []string
+
+// IsCompressorNameRegistered returns true when name is available in registry.
+func IsCompressorNameRegistered(name string) bool {
+	for _, compressor := range RegisteredCompressorNames {
+		if compressor == name {
+			return true
+		}
+	}
+	return false
+}
+
+// RegisteredCompressors returns a string of registered compressor names
+// separated by comma.
+func RegisteredCompressors() string {
+	if !envconfig.AdvertiseCompressors {
+		return ""
+	}
+	return strings.Join(RegisteredCompressorNames, ",")
+}
diff --git a/vendor/google.golang.org/grpc/internal/grpcutil/method.go b/vendor/google.golang.org/grpc/internal/grpcutil/method.go
index c6f2012..ec62b47 100644
--- a/vendor/google.golang.org/grpc/internal/grpcutil/method.go
+++ b/vendor/google.golang.org/grpc/internal/grpcutil/method.go
@@ -38,6 +38,11 @@
 	return methodName[:pos], methodName[pos+1:], nil
 }
 
+// baseContentType is the base content-type for gRPC.  This is a valid
+// content-type on it's own, but can also include a content-subtype such as
+// "proto" as a suffix after "+" or ";".  See
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
+// for more details.
 const baseContentType = "application/grpc"
 
 // ContentSubtype returns the content-subtype for the given content-type.  The
diff --git a/vendor/google.golang.org/grpc/internal/internal.go b/vendor/google.golang.org/grpc/internal/internal.go
index 1b596bf..42ff39c 100644
--- a/vendor/google.golang.org/grpc/internal/internal.go
+++ b/vendor/google.golang.org/grpc/internal/internal.go
@@ -38,11 +38,10 @@
 	// 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
-	// ParseServiceConfigForTesting is for creating a fake
-	// ClientConn for resolver testing only
-	ParseServiceConfigForTesting interface{} // func(string) *serviceconfig.ParseResult
+	// ParseServiceConfig parses a JSON representation of the service config.
+	ParseServiceConfig interface{} // func(string) *serviceconfig.ParseResult
 	// EqualServiceConfigForTesting is for testing service config generation and
-	// parsing. Both a and b should be returned by ParseServiceConfigForTesting.
+	// parsing. Both a and b should be returned by ParseServiceConfig.
 	// This function compares the config without rawJSON stripped, in case the
 	// there's difference in white space.
 	EqualServiceConfigForTesting func(a, b serviceconfig.Config) bool
@@ -59,11 +58,112 @@
 	// gRPC server. An xDS-enabled server needs to know what type of credentials
 	// is configured on the underlying gRPC server. This is set by server.go.
 	GetServerCredentials interface{} // func (*grpc.Server) credentials.TransportCredentials
+	// CanonicalString returns the canonical string of the code defined here:
+	// https://github.com/grpc/grpc/blob/master/doc/statuscodes.md.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	CanonicalString interface{} // func (codes.Code) string
 	// DrainServerTransports initiates a graceful close of existing connections
 	// on a gRPC server accepted on the provided listener address. An
 	// xDS-enabled server invokes this method on a grpc.Server when a particular
 	// listener moves to "not-serving" mode.
 	DrainServerTransports interface{} // func(*grpc.Server, string)
+	// AddGlobalServerOptions adds an array of ServerOption that will be
+	// effective globally for newly created servers. The priority will be: 1.
+	// user-provided; 2. this method; 3. default values.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	AddGlobalServerOptions interface{} // func(opt ...ServerOption)
+	// ClearGlobalServerOptions clears the array of extra ServerOption. This
+	// method is useful in testing and benchmarking.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	ClearGlobalServerOptions func()
+	// AddGlobalDialOptions adds an array of DialOption that will be effective
+	// globally for newly created client channels. The priority will be: 1.
+	// user-provided; 2. this method; 3. default values.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	AddGlobalDialOptions interface{} // func(opt ...DialOption)
+	// DisableGlobalDialOptions returns a DialOption that prevents the
+	// ClientConn from applying the global DialOptions (set via
+	// AddGlobalDialOptions).
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	DisableGlobalDialOptions interface{} // func() grpc.DialOption
+	// ClearGlobalDialOptions clears the array of extra DialOption. This
+	// method is useful in testing and benchmarking.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	ClearGlobalDialOptions func()
+	// JoinDialOptions combines the dial options passed as arguments into a
+	// single dial option.
+	JoinDialOptions interface{} // func(...grpc.DialOption) grpc.DialOption
+	// JoinServerOptions combines the server options passed as arguments into a
+	// single server option.
+	JoinServerOptions interface{} // func(...grpc.ServerOption) grpc.ServerOption
+
+	// WithBinaryLogger returns a DialOption that specifies the binary logger
+	// for a ClientConn.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	WithBinaryLogger interface{} // func(binarylog.Logger) grpc.DialOption
+	// BinaryLogger returns a ServerOption that can set the binary logger for a
+	// server.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	BinaryLogger interface{} // func(binarylog.Logger) grpc.ServerOption
+
+	// NewXDSResolverWithConfigForTesting creates a new xds resolver builder using
+	// the provided xds bootstrap config instead of the global configuration from
+	// the supported environment variables.  The resolver.Builder is meant to be
+	// used in conjunction with the grpc.WithResolvers DialOption.
+	//
+	// Testing Only
+	//
+	// This function should ONLY be used for testing and may not work with some
+	// other features, including the CSDS service.
+	NewXDSResolverWithConfigForTesting interface{} // func([]byte) (resolver.Builder, error)
+
+	// RegisterRLSClusterSpecifierPluginForTesting registers the RLS Cluster
+	// Specifier Plugin for testing purposes, regardless of the XDSRLS environment
+	// variable.
+	//
+	// TODO: Remove this function once the RLS env var is removed.
+	RegisterRLSClusterSpecifierPluginForTesting func()
+
+	// UnregisterRLSClusterSpecifierPluginForTesting unregisters the RLS Cluster
+	// Specifier Plugin for testing purposes. This is needed because there is no way
+	// to unregister the RLS Cluster Specifier Plugin after registering it solely
+	// for testing purposes using RegisterRLSClusterSpecifierPluginForTesting().
+	//
+	// TODO: Remove this function once the RLS env var is removed.
+	UnregisterRLSClusterSpecifierPluginForTesting func()
+
+	// RegisterRBACHTTPFilterForTesting registers the RBAC HTTP Filter for testing
+	// purposes, regardless of the RBAC environment variable.
+	//
+	// TODO: Remove this function once the RBAC env var is removed.
+	RegisterRBACHTTPFilterForTesting func()
+
+	// UnregisterRBACHTTPFilterForTesting unregisters the RBAC HTTP Filter for
+	// testing purposes. This is needed because there is no way to unregister the
+	// HTTP Filter after registering it solely for testing purposes using
+	// RegisterRBACHTTPFilterForTesting().
+	//
+	// TODO: Remove this function once the RBAC env var is removed.
+	UnregisterRBACHTTPFilterForTesting func()
+
+	// ORCAAllowAnyMinReportingInterval is for examples/orca use ONLY.
+	ORCAAllowAnyMinReportingInterval interface{} // func(so *orca.ServiceOptions)
 )
 
 // HealthChecker defines the signature of the client-side LB channel health checking function.
@@ -86,3 +186,9 @@
 	// that supports backend returned by grpclb balancer.
 	CredsBundleModeBackendFromBalancer = "backend-from-balancer"
 )
+
+// RLSLoadBalancingPolicyName is the name of the RLS LB policy.
+//
+// It currently has an experimental suffix which would be removed once
+// end-to-end testing of the policy is completed.
+const RLSLoadBalancingPolicyName = "rls_experimental"
diff --git a/vendor/google.golang.org/grpc/internal/metadata/metadata.go b/vendor/google.golang.org/grpc/internal/metadata/metadata.go
index b8733db..c82e608 100644
--- a/vendor/google.golang.org/grpc/internal/metadata/metadata.go
+++ b/vendor/google.golang.org/grpc/internal/metadata/metadata.go
@@ -22,6 +22,9 @@
 package metadata
 
 import (
+	"fmt"
+	"strings"
+
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/resolver"
 )
@@ -72,3 +75,58 @@
 	addr.Attributes = addr.Attributes.WithValue(mdKey, mdValue(md))
 	return addr
 }
+
+// Validate validates every pair in md with ValidatePair.
+func Validate(md metadata.MD) error {
+	for k, vals := range md {
+		if err := ValidatePair(k, vals...); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// hasNotPrintable return true if msg contains any characters which are not in %x20-%x7E
+func hasNotPrintable(msg string) bool {
+	// for i that saving a conversion if not using for range
+	for i := 0; i < len(msg); i++ {
+		if msg[i] < 0x20 || msg[i] > 0x7E {
+			return true
+		}
+	}
+	return false
+}
+
+// ValidatePair validate a key-value pair with the following rules (the pseudo-header will be skipped) :
+//
+// - key must contain one or more characters.
+// - the characters in the key must be contained in [0-9 a-z _ - .].
+// - if the key ends with a "-bin" suffix, no validation of the corresponding value is performed.
+// - the characters in the every value must be printable (in [%x20-%x7E]).
+func ValidatePair(key string, vals ...string) error {
+	// key should not be empty
+	if key == "" {
+		return fmt.Errorf("there is an empty key in the header")
+	}
+	// pseudo-header will be ignored
+	if key[0] == ':' {
+		return nil
+	}
+	// check key, for i that saving a conversion if not using for range
+	for i := 0; i < len(key); i++ {
+		r := key[i]
+		if !(r >= 'a' && r <= 'z') && !(r >= '0' && r <= '9') && r != '.' && r != '-' && r != '_' {
+			return fmt.Errorf("header key %q contains illegal characters not in [0-9a-z-_.]", key)
+		}
+	}
+	if strings.HasSuffix(key, "-bin") {
+		return nil
+	}
+	// check value
+	for _, val := range vals {
+		if hasNotPrintable(val) {
+			return fmt.Errorf("header key %q contains value with non-printable ASCII characters", key)
+		}
+	}
+	return nil
+}
diff --git a/vendor/google.golang.org/grpc/internal/pretty/pretty.go b/vendor/google.golang.org/grpc/internal/pretty/pretty.go
new file mode 100644
index 0000000..0177af4
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/pretty/pretty.go
@@ -0,0 +1,82 @@
+/*
+ *
+ * Copyright 2021 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 pretty defines helper functions to pretty-print structs for logging.
+package pretty
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+
+	"github.com/golang/protobuf/jsonpb"
+	protov1 "github.com/golang/protobuf/proto"
+	"google.golang.org/protobuf/encoding/protojson"
+	protov2 "google.golang.org/protobuf/proto"
+)
+
+const jsonIndent = "  "
+
+// ToJSON marshals the input into a json string.
+//
+// If marshal fails, it falls back to fmt.Sprintf("%+v").
+func ToJSON(e interface{}) string {
+	switch ee := e.(type) {
+	case protov1.Message:
+		mm := jsonpb.Marshaler{Indent: jsonIndent}
+		ret, err := mm.MarshalToString(ee)
+		if err != nil {
+			// This may fail for proto.Anys, e.g. for xDS v2, LDS, the v2
+			// messages are not imported, and this will fail because the message
+			// is not found.
+			return fmt.Sprintf("%+v", ee)
+		}
+		return ret
+	case protov2.Message:
+		mm := protojson.MarshalOptions{
+			Multiline: true,
+			Indent:    jsonIndent,
+		}
+		ret, err := mm.Marshal(ee)
+		if err != nil {
+			// This may fail for proto.Anys, e.g. for xDS v2, LDS, the v2
+			// messages are not imported, and this will fail because the message
+			// is not found.
+			return fmt.Sprintf("%+v", ee)
+		}
+		return string(ret)
+	default:
+		ret, err := json.MarshalIndent(ee, "", jsonIndent)
+		if err != nil {
+			return fmt.Sprintf("%+v", ee)
+		}
+		return string(ret)
+	}
+}
+
+// FormatJSON formats the input json bytes with indentation.
+//
+// If Indent fails, it returns the unchanged input as string.
+func FormatJSON(b []byte) string {
+	var out bytes.Buffer
+	err := json.Indent(&out, b, "", jsonIndent)
+	if err != nil {
+		return string(b)
+	}
+	return out.String()
+}
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 75301c5..09a667f 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
@@ -116,7 +116,7 @@
 
 // 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)
+	host, port, err := parseTarget(target.Endpoint(), defaultPort)
 	if err != nil {
 		return nil, err
 	}
@@ -140,10 +140,10 @@
 		disableServiceConfig: opts.DisableServiceConfig,
 	}
 
-	if target.Authority == "" {
+	if target.URL.Host == "" {
 		d.resolver = defaultResolver
 	} else {
-		d.resolver, err = customAuthorityResolver(target.Authority)
+		d.resolver, err = customAuthorityResolver(target.URL.Host)
 		if err != nil {
 			return nil, 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..afac565 100644
--- a/vendor/google.golang.org/grpc/internal/resolver/passthrough/passthrough.go
+++ b/vendor/google.golang.org/grpc/internal/resolver/passthrough/passthrough.go
@@ -20,13 +20,20 @@
 // name without scheme back to gRPC as resolved address.
 package passthrough
 
-import "google.golang.org/grpc/resolver"
+import (
+	"errors"
+
+	"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) {
+	if target.Endpoint() == "" && opts.Dialer == nil {
+		return nil, errors.New("passthrough: received empty target in Build()")
+	}
 	r := &passthroughResolver{
 		target: target,
 		cc:     cc,
@@ -45,7 +52,7 @@
 }
 
 func (r *passthroughResolver) start() {
-	r.cc.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: r.target.Endpoint}}})
+	r.cc.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: r.target.Endpoint()}}})
 }
 
 func (*passthroughResolver) ResolveNow(o resolver.ResolveNowOptions) {}
diff --git a/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go b/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go
index 20852e5..1609116 100644
--- a/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go
+++ b/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go
@@ -34,8 +34,8 @@
 }
 
 func (b *builder) Build(target resolver.Target, cc resolver.ClientConn, _ resolver.BuildOptions) (resolver.Resolver, error) {
-	if target.Authority != "" {
-		return nil, fmt.Errorf("invalid (non-empty) authority: %v", target.Authority)
+	if target.URL.Host != "" {
+		return nil, fmt.Errorf("invalid (non-empty) authority: %v", target.URL.Host)
 	}
 
 	// gRPC was parsing the dial target manually before PR #4817, and we
@@ -49,8 +49,9 @@
 	}
 	addr := resolver.Address{Addr: endpoint}
 	if b.scheme == unixAbstractScheme {
-		// prepend "\x00" to address for unix-abstract
-		addr.Addr = "\x00" + addr.Addr
+		// We can not prepend \0 as c++ gRPC does, as in Golang '@' is used to signify we do
+		// not want trailing \0 in address.
+		addr.Addr = "@" + addr.Addr
 	}
 	cc.UpdateState(resolver.State{Addresses: []resolver.Address{networktype.Set(addr, "unix")}})
 	return &nopResolver{}, nil
diff --git a/vendor/google.golang.org/grpc/internal/serviceconfig/duration.go b/vendor/google.golang.org/grpc/internal/serviceconfig/duration.go
new file mode 100644
index 0000000..11d82af
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/serviceconfig/duration.go
@@ -0,0 +1,130 @@
+/*
+ *
+ * Copyright 2023 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 serviceconfig
+
+import (
+	"encoding/json"
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Duration defines JSON marshal and unmarshal methods to conform to the
+// protobuf JSON spec defined [here].
+//
+// [here]: https://protobuf.dev/reference/protobuf/google.protobuf/#duration
+type Duration time.Duration
+
+func (d Duration) String() string {
+	return fmt.Sprint(time.Duration(d))
+}
+
+// MarshalJSON converts from d to a JSON string output.
+func (d Duration) MarshalJSON() ([]byte, error) {
+	ns := time.Duration(d).Nanoseconds()
+	sec := ns / int64(time.Second)
+	ns = ns % int64(time.Second)
+
+	var sign string
+	if sec < 0 || ns < 0 {
+		sign, sec, ns = "-", -1*sec, -1*ns
+	}
+
+	// Generated output always contains 0, 3, 6, or 9 fractional digits,
+	// depending on required precision.
+	str := fmt.Sprintf("%s%d.%09d", sign, sec, ns)
+	str = strings.TrimSuffix(str, "000")
+	str = strings.TrimSuffix(str, "000")
+	str = strings.TrimSuffix(str, ".000")
+	return []byte(fmt.Sprintf("\"%ss\"", str)), nil
+}
+
+// UnmarshalJSON unmarshals b as a duration JSON string into d.
+func (d *Duration) UnmarshalJSON(b []byte) error {
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+	if !strings.HasSuffix(s, "s") {
+		return fmt.Errorf("malformed duration %q: missing seconds unit", s)
+	}
+	neg := false
+	if s[0] == '-' {
+		neg = true
+		s = s[1:]
+	}
+	ss := strings.SplitN(s[:len(s)-1], ".", 3)
+	if len(ss) > 2 {
+		return fmt.Errorf("malformed duration %q: too many decimals", s)
+	}
+	// hasDigits is set if either the whole or fractional part of the number is
+	// present, since both are optional but one is required.
+	hasDigits := false
+	var sec, ns int64
+	if len(ss[0]) > 0 {
+		var err error
+		if sec, err = strconv.ParseInt(ss[0], 10, 64); err != nil {
+			return fmt.Errorf("malformed duration %q: %v", s, err)
+		}
+		// Maximum seconds value per the durationpb spec.
+		const maxProtoSeconds = 315_576_000_000
+		if sec > maxProtoSeconds {
+			return fmt.Errorf("out of range: %q", s)
+		}
+		hasDigits = true
+	}
+	if len(ss) == 2 && len(ss[1]) > 0 {
+		if len(ss[1]) > 9 {
+			return fmt.Errorf("malformed duration %q: too many digits after decimal", s)
+		}
+		var err error
+		if ns, err = strconv.ParseInt(ss[1], 10, 64); err != nil {
+			return fmt.Errorf("malformed duration %q: %v", s, err)
+		}
+		for i := 9; i > len(ss[1]); i-- {
+			ns *= 10
+		}
+		hasDigits = true
+	}
+	if !hasDigits {
+		return fmt.Errorf("malformed duration %q: contains no numbers", s)
+	}
+
+	if neg {
+		sec *= -1
+		ns *= -1
+	}
+
+	// Maximum/minimum seconds/nanoseconds representable by Go's time.Duration.
+	const maxSeconds = math.MaxInt64 / int64(time.Second)
+	const maxNanosAtMaxSeconds = math.MaxInt64 % int64(time.Second)
+	const minSeconds = math.MinInt64 / int64(time.Second)
+	const minNanosAtMinSeconds = math.MinInt64 % int64(time.Second)
+
+	if sec > maxSeconds || (sec == maxSeconds && ns >= maxNanosAtMaxSeconds) {
+		*d = Duration(math.MaxInt64)
+	} else if sec < minSeconds || (sec == minSeconds && ns <= minNanosAtMinSeconds) {
+		*d = Duration(math.MinInt64)
+	} else {
+		*d = Duration(sec*int64(time.Second) + ns)
+	}
+	return nil
+}
diff --git a/vendor/google.golang.org/grpc/internal/status/status.go b/vendor/google.golang.org/grpc/internal/status/status.go
index e5c6513..b0ead4f 100644
--- a/vendor/google.golang.org/grpc/internal/status/status.go
+++ b/vendor/google.golang.org/grpc/internal/status/status.go
@@ -164,3 +164,13 @@
 	}
 	return proto.Equal(e.s.s, tse.s.s)
 }
+
+// IsRestrictedControlPlaneCode returns whether the status includes a code
+// restricted for control plane usage as defined by gRFC A54.
+func IsRestrictedControlPlaneCode(s *Status) bool {
+	switch s.Code() {
+	case codes.InvalidArgument, codes.NotFound, codes.AlreadyExists, codes.FailedPrecondition, codes.Aborted, codes.OutOfRange, codes.DataLoss:
+		return true
+	}
+	return false
+}
diff --git a/vendor/google.golang.org/grpc/internal/transport/controlbuf.go b/vendor/google.golang.org/grpc/internal/transport/controlbuf.go
index 8394d25..be5a9c8 100644
--- a/vendor/google.golang.org/grpc/internal/transport/controlbuf.go
+++ b/vendor/google.golang.org/grpc/internal/transport/controlbuf.go
@@ -22,6 +22,7 @@
 	"bytes"
 	"errors"
 	"fmt"
+	"net"
 	"runtime"
 	"strconv"
 	"sync"
@@ -29,6 +30,7 @@
 
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
+	"google.golang.org/grpc/internal/grpclog"
 	"google.golang.org/grpc/internal/grpcutil"
 	"google.golang.org/grpc/status"
 )
@@ -137,6 +139,7 @@
 	streamID       uint32
 	contentSubtype string
 	status         *status.Status
+	rst            bool
 }
 
 func (*earlyAbortStream) isTransportResponseFrame() bool { return false }
@@ -190,7 +193,7 @@
 	code      http2.ErrCode
 	debugData []byte
 	headsUp   bool
-	closeConn bool
+	closeConn error // if set, loopyWriter will exit, resulting in conn closure
 }
 
 func (*goAway) isTransportResponseFrame() bool { return false }
@@ -208,6 +211,14 @@
 
 func (*outFlowControlSizeRequest) isTransportResponseFrame() bool { return false }
 
+// closeConnection is an instruction to tell the loopy writer to flush the
+// framer and exit, which will cause the transport's connection to be closed
+// (by the client or server).  The transport itself will close after the reader
+// encounters the EOF caused by the connection closure.
+type closeConnection struct{}
+
+func (closeConnection) isTransportResponseFrame() bool { return false }
+
 type outStreamState int
 
 const (
@@ -407,7 +418,7 @@
 		select {
 		case <-c.ch:
 		case <-c.done:
-			return nil, ErrConnClosing
+			return nil, errors.New("transport closed by client")
 		}
 	}
 }
@@ -477,12 +488,14 @@
 	hEnc          *hpack.Encoder // HPACK encoder.
 	bdpEst        *bdpEstimator
 	draining      bool
+	conn          net.Conn
+	logger        *grpclog.PrefixLogger
 
 	// Side-specific handlers
 	ssGoAwayHandler func(*goAway) (bool, error)
 }
 
-func newLoopyWriter(s side, fr *framer, cbuf *controlBuffer, bdpEst *bdpEstimator) *loopyWriter {
+func newLoopyWriter(s side, fr *framer, cbuf *controlBuffer, bdpEst *bdpEstimator, conn net.Conn, logger *grpclog.PrefixLogger) *loopyWriter {
 	var buf bytes.Buffer
 	l := &loopyWriter{
 		side:          s,
@@ -495,6 +508,8 @@
 		hBuf:          &buf,
 		hEnc:          hpack.NewEncoder(&buf),
 		bdpEst:        bdpEst,
+		conn:          conn,
+		logger:        logger,
 	}
 	return l
 }
@@ -512,23 +527,26 @@
 // 2. Stream level flow control quota available.
 //
 // In each iteration of run loop, other than processing the incoming control
-// frame, loopy calls processData, which processes one node from the activeStreams linked-list.
-// This results in writing of HTTP2 frames into an underlying write buffer.
-// When there's no more control frames to read from controlBuf, loopy flushes the write buffer.
-// As an optimization, to increase the batch size for each flush, loopy yields the processor, once
-// if the batch size is too low to give stream goroutines a chance to fill it up.
+// frame, loopy calls processData, which processes one node from the
+// activeStreams linked-list.  This results in writing of HTTP2 frames into an
+// underlying write buffer.  When there's no more control frames to read from
+// controlBuf, loopy flushes the write buffer.  As an optimization, to increase
+// the batch size for each flush, loopy yields the processor, once if the batch
+// size is too low to give stream goroutines a chance to fill it up.
+//
+// Upon exiting, if the error causing the exit is not an I/O error, run()
+// flushes and closes the underlying connection.  Otherwise, the connection is
+// left open to allow the I/O error to be encountered by the reader instead.
 func (l *loopyWriter) run() (err error) {
 	defer func() {
-		if err == ErrConnClosing {
-			// Don't log ErrConnClosing as error since it happens
-			// 1. When the connection is closed by some other known issue.
-			// 2. User closed the connection.
-			// 3. A graceful close of connection.
-			if logger.V(logLevel) {
-				logger.Infof("transport: loopyWriter.run returning. %v", err)
-			}
-			err = nil
+		if l.logger.V(logLevel) {
+			l.logger.Infof("loopyWriter exiting with error: %v", err)
 		}
+		if !isIOError(err) {
+			l.framer.writer.Flush()
+			l.conn.Close()
+		}
+		l.cbuf.finish()
 	}()
 	for {
 		it, err := l.cbuf.get(true)
@@ -573,7 +591,6 @@
 			}
 			l.framer.writer.Flush()
 			break hasdata
-
 		}
 	}
 }
@@ -582,11 +599,11 @@
 	return l.framer.fr.WriteWindowUpdate(w.streamID, w.increment)
 }
 
-func (l *loopyWriter) incomingWindowUpdateHandler(w *incomingWindowUpdate) error {
+func (l *loopyWriter) incomingWindowUpdateHandler(w *incomingWindowUpdate) {
 	// Otherwise update the quota.
 	if w.streamID == 0 {
 		l.sendQuota += w.increment
-		return nil
+		return
 	}
 	// Find the stream and update it.
 	if str, ok := l.estdStreams[w.streamID]; ok {
@@ -594,10 +611,9 @@
 		if strQuota := int(l.oiws) - str.bytesOutStanding; strQuota > 0 && str.state == waitingOnStreamQuota {
 			str.state = active
 			l.activeStreams.enqueue(str)
-			return nil
+			return
 		}
 	}
-	return nil
 }
 
 func (l *loopyWriter) outgoingSettingsHandler(s *outgoingSettings) error {
@@ -605,13 +621,11 @@
 }
 
 func (l *loopyWriter) incomingSettingsHandler(s *incomingSettings) error {
-	if err := l.applySettings(s.ss); err != nil {
-		return err
-	}
+	l.applySettings(s.ss)
 	return l.framer.fr.WriteSettingsAck()
 }
 
-func (l *loopyWriter) registerStreamHandler(h *registerStream) error {
+func (l *loopyWriter) registerStreamHandler(h *registerStream) {
 	str := &outStream{
 		id:    h.streamID,
 		state: empty,
@@ -619,15 +633,14 @@
 		wq:    h.wq,
 	}
 	l.estdStreams[h.streamID] = str
-	return nil
 }
 
 func (l *loopyWriter) headerHandler(h *headerFrame) error {
 	if l.side == serverSide {
 		str, ok := l.estdStreams[h.streamID]
 		if !ok {
-			if logger.V(logLevel) {
-				logger.Warningf("transport: loopy doesn't recognize the stream: %d", h.streamID)
+			if l.logger.V(logLevel) {
+				l.logger.Infof("Unrecognized streamID %d in loopyWriter", h.streamID)
 			}
 			return nil
 		}
@@ -654,19 +667,20 @@
 		itl:   &itemList{},
 		wq:    h.wq,
 	}
-	str.itl.enqueue(h)
-	return l.originateStream(str)
+	return l.originateStream(str, h)
 }
 
-func (l *loopyWriter) originateStream(str *outStream) error {
-	hdr := str.itl.dequeue().(*headerFrame)
-	if err := hdr.initStream(str.id); err != nil {
-		if err == ErrConnClosing {
-			return err
-		}
-		// Other errors(errStreamDrain) need not close transport.
+func (l *loopyWriter) originateStream(str *outStream, hdr *headerFrame) error {
+	// l.draining is set when handling GoAway. In which case, we want to avoid
+	// creating new streams.
+	if l.draining {
+		// TODO: provide a better error with the reason we are in draining.
+		hdr.onOrphaned(errStreamDrain)
 		return nil
 	}
+	if err := hdr.initStream(str.id); err != nil {
+		return err
+	}
 	if err := l.writeHeader(str.id, hdr.endStream, hdr.hf, hdr.onWrite); err != nil {
 		return err
 	}
@@ -681,8 +695,8 @@
 	l.hBuf.Reset()
 	for _, f := range hf {
 		if err := l.hEnc.WriteField(f); err != nil {
-			if logger.V(logLevel) {
-				logger.Warningf("transport: loopyWriter.writeHeader encountered error while encoding headers: %v", err)
+			if l.logger.V(logLevel) {
+				l.logger.Warningf("Encountered error while encoding headers: %v", err)
 			}
 		}
 	}
@@ -720,10 +734,10 @@
 	return nil
 }
 
-func (l *loopyWriter) preprocessData(df *dataFrame) error {
+func (l *loopyWriter) preprocessData(df *dataFrame) {
 	str, ok := l.estdStreams[df.streamID]
 	if !ok {
-		return nil
+		return
 	}
 	// If we got data for a stream it means that
 	// stream was originated and the headers were sent out.
@@ -732,7 +746,6 @@
 		str.state = active
 		l.activeStreams.enqueue(str)
 	}
-	return nil
 }
 
 func (l *loopyWriter) pingHandler(p *ping) error {
@@ -743,9 +756,8 @@
 
 }
 
-func (l *loopyWriter) outFlowControlSizeRequestHandler(o *outFlowControlSizeRequest) error {
+func (l *loopyWriter) outFlowControlSizeRequestHandler(o *outFlowControlSizeRequest) {
 	o.resp <- l.sendQuota
-	return nil
 }
 
 func (l *loopyWriter) cleanupStreamHandler(c *cleanupStream) error {
@@ -762,8 +774,9 @@
 			return err
 		}
 	}
-	if l.side == clientSide && l.draining && len(l.estdStreams) == 0 {
-		return ErrConnClosing
+	if l.draining && len(l.estdStreams) == 0 {
+		// Flush and close the connection; we are done with it.
+		return errors.New("finished processing active streams while in draining mode")
 	}
 	return nil
 }
@@ -786,6 +799,11 @@
 	if err := l.writeHeader(eas.streamID, true, headerFields, nil); err != nil {
 		return err
 	}
+	if eas.rst {
+		if err := l.framer.fr.WriteRSTStream(eas.streamID, http2.ErrCodeNo); err != nil {
+			return err
+		}
+	}
 	return nil
 }
 
@@ -793,7 +811,8 @@
 	if l.side == clientSide {
 		l.draining = true
 		if len(l.estdStreams) == 0 {
-			return ErrConnClosing
+			// Flush and close the connection; we are done with it.
+			return errors.New("received GOAWAY with no active streams")
 		}
 	}
 	return nil
@@ -814,7 +833,7 @@
 func (l *loopyWriter) handle(i interface{}) error {
 	switch i := i.(type) {
 	case *incomingWindowUpdate:
-		return l.incomingWindowUpdateHandler(i)
+		l.incomingWindowUpdateHandler(i)
 	case *outgoingWindowUpdate:
 		return l.outgoingWindowUpdateHandler(i)
 	case *incomingSettings:
@@ -824,7 +843,7 @@
 	case *headerFrame:
 		return l.headerHandler(i)
 	case *registerStream:
-		return l.registerStreamHandler(i)
+		l.registerStreamHandler(i)
 	case *cleanupStream:
 		return l.cleanupStreamHandler(i)
 	case *earlyAbortStream:
@@ -832,19 +851,24 @@
 	case *incomingGoAway:
 		return l.incomingGoAwayHandler(i)
 	case *dataFrame:
-		return l.preprocessData(i)
+		l.preprocessData(i)
 	case *ping:
 		return l.pingHandler(i)
 	case *goAway:
 		return l.goAwayHandler(i)
 	case *outFlowControlSizeRequest:
-		return l.outFlowControlSizeRequestHandler(i)
+		l.outFlowControlSizeRequestHandler(i)
+	case closeConnection:
+		// Just return a non-I/O error and run() will flush and close the
+		// connection.
+		return ErrConnClosing
 	default:
 		return fmt.Errorf("transport: unknown control message type %T", i)
 	}
+	return nil
 }
 
-func (l *loopyWriter) applySettings(ss []http2.Setting) error {
+func (l *loopyWriter) applySettings(ss []http2.Setting) {
 	for _, s := range ss {
 		switch s.ID {
 		case http2.SettingInitialWindowSize:
@@ -863,7 +887,6 @@
 			updateHeaderTblSize(l.hEnc, s.Val)
 		}
 	}
-	return nil
 }
 
 // processData removes the first stream from active streams, writes out at most 16KB
@@ -880,9 +903,9 @@
 	dataItem := str.itl.peek().(*dataFrame) // Peek at the first data item this stream.
 	// A data item is represented by a dataFrame, since it later translates into
 	// multiple HTTP2 data frames.
-	// Every dataFrame has two buffers; h that keeps grpc-message header and d that is acutal data.
+	// Every dataFrame has two buffers; h that keeps grpc-message header and d that is actual data.
 	// As an optimization to keep wire traffic low, data from d is copied to h to make as big as the
-	// maximum possilbe HTTP2 frame size.
+	// maximum possible HTTP2 frame size.
 
 	if len(dataItem.h) == 0 && len(dataItem.d) == 0 { // Empty data frame
 		// Client sends out empty data frame with endStream = true
@@ -897,7 +920,7 @@
 				return false, err
 			}
 			if err := l.cleanupStreamHandler(trailer.cleanup); err != nil {
-				return false, nil
+				return false, err
 			}
 		} else {
 			l.activeStreams.enqueue(str)
diff --git a/vendor/google.golang.org/grpc/internal/transport/defaults.go b/vendor/google.golang.org/grpc/internal/transport/defaults.go
index 9fa306b..bc8ee07 100644
--- a/vendor/google.golang.org/grpc/internal/transport/defaults.go
+++ b/vendor/google.golang.org/grpc/internal/transport/defaults.go
@@ -47,3 +47,9 @@
 	defaultClientMaxHeaderListSize = uint32(16 << 20)
 	defaultServerMaxHeaderListSize = uint32(16 << 20)
 )
+
+// MaxStreamID is the upper bound for the stream ID before the current
+// transport gracefully closes and new transport is created for subsequent RPCs.
+// This is set to 75% of 2^31-1. Streams are identified with an unsigned 31-bit
+// integer. It's exported so that tests can override it.
+var MaxStreamID = uint32(math.MaxInt32 * 3 / 4)
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 b897cba..98f80e3 100644
--- a/vendor/google.golang.org/grpc/internal/transport/handler_server.go
+++ b/vendor/google.golang.org/grpc/internal/transport/handler_server.go
@@ -39,6 +39,7 @@
 	"golang.org/x/net/http2"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/internal/grpclog"
 	"google.golang.org/grpc/internal/grpcutil"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/peer"
@@ -46,24 +47,32 @@
 	"google.golang.org/grpc/status"
 )
 
-// NewServerHandlerTransport returns a ServerTransport handling gRPC
-// from inside an http.Handler. It requires that the http Server
-// supports HTTP/2.
-func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request, stats stats.Handler) (ServerTransport, error) {
+// NewServerHandlerTransport returns a ServerTransport handling gRPC from
+// inside an http.Handler, or writes an HTTP error to w and returns an error.
+// It requires that the http Server supports HTTP/2.
+func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request, stats []stats.Handler) (ServerTransport, error) {
 	if r.ProtoMajor != 2 {
-		return nil, errors.New("gRPC requires HTTP/2")
+		msg := "gRPC requires HTTP/2"
+		http.Error(w, msg, http.StatusBadRequest)
+		return nil, errors.New(msg)
 	}
 	if r.Method != "POST" {
-		return nil, errors.New("invalid gRPC request method")
+		msg := fmt.Sprintf("invalid gRPC request method %q", r.Method)
+		http.Error(w, msg, http.StatusBadRequest)
+		return nil, errors.New(msg)
 	}
 	contentType := r.Header.Get("Content-Type")
 	// TODO: do we assume contentType is lowercase? we did before
 	contentSubtype, validContentType := grpcutil.ContentSubtype(contentType)
 	if !validContentType {
-		return nil, errors.New("invalid gRPC request content-type")
+		msg := fmt.Sprintf("invalid gRPC request content-type %q", contentType)
+		http.Error(w, msg, http.StatusUnsupportedMediaType)
+		return nil, errors.New(msg)
 	}
 	if _, ok := w.(http.Flusher); !ok {
-		return nil, errors.New("gRPC requires a ResponseWriter supporting http.Flusher")
+		msg := "gRPC requires a ResponseWriter supporting http.Flusher"
+		http.Error(w, msg, http.StatusInternalServerError)
+		return nil, errors.New(msg)
 	}
 
 	st := &serverHandlerTransport{
@@ -75,11 +84,14 @@
 		contentSubtype: contentSubtype,
 		stats:          stats,
 	}
+	st.logger = prefixLoggerForServerHandlerTransport(st)
 
 	if v := r.Header.Get("grpc-timeout"); v != "" {
 		to, err := decodeTimeout(v)
 		if err != nil {
-			return nil, status.Errorf(codes.Internal, "malformed time-out: %v", err)
+			msg := fmt.Sprintf("malformed grpc-timeout: %v", err)
+			http.Error(w, msg, http.StatusBadRequest)
+			return nil, status.Error(codes.Internal, msg)
 		}
 		st.timeoutSet = true
 		st.timeout = to
@@ -97,7 +109,9 @@
 		for _, v := range vv {
 			v, err := decodeMetadataHeader(k, v)
 			if err != nil {
-				return nil, status.Errorf(codes.Internal, "malformed binary metadata: %v", err)
+				msg := fmt.Sprintf("malformed binary metadata %q in header %q: %v", v, k, err)
+				http.Error(w, msg, http.StatusBadRequest)
+				return nil, status.Error(codes.Internal, msg)
 			}
 			metakv = append(metakv, k, v)
 		}
@@ -138,15 +152,19 @@
 	// TODO make sure this is consistent across handler_server and http2_server
 	contentSubtype string
 
-	stats stats.Handler
+	stats  []stats.Handler
+	logger *grpclog.PrefixLogger
 }
 
-func (ht *serverHandlerTransport) Close() {
-	ht.closeOnce.Do(ht.closeCloseChanOnce)
+func (ht *serverHandlerTransport) Close(err error) {
+	ht.closeOnce.Do(func() {
+		if ht.logger.V(logLevel) {
+			ht.logger.Infof("Closing: %v", err)
+		}
+		close(ht.closedCh)
+	})
 }
 
-func (ht *serverHandlerTransport) closeCloseChanOnce() { close(ht.closedCh) }
-
 func (ht *serverHandlerTransport) RemoteAddr() net.Addr { return strAddr(ht.req.RemoteAddr) }
 
 // strAddr is a net.Addr backed by either a TCP "ip:port" string, or
@@ -228,15 +246,15 @@
 	})
 
 	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{
+		// Note: The trailer fields are compressed with hpack after this call returns.
+		// No WireLength field is set here.
+		for _, sh := range ht.stats {
+			sh.HandleRPC(s.Context(), &stats.OutTrailer{
 				Trailer: s.trailer.Copy(),
 			})
 		}
 	}
-	ht.Close()
+	ht.Close(errors.New("finished writing status"))
 	return err
 }
 
@@ -314,10 +332,10 @@
 	})
 
 	if err == nil {
-		if ht.stats != nil {
+		for _, sh := range ht.stats {
 			// 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{
+			sh.HandleRPC(s.Context(), &stats.OutHeader{
 				Header:      md.Copy(),
 				Compression: s.sendCompress,
 			})
@@ -346,7 +364,7 @@
 		case <-ht.req.Context().Done():
 		}
 		cancel()
-		ht.Close()
+		ht.Close(errors.New("request is done processing"))
 	}()
 
 	req := ht.req
@@ -369,14 +387,14 @@
 	}
 	ctx = metadata.NewIncomingContext(ctx, ht.headerMD)
 	s.ctx = peer.NewContext(ctx, pr)
-	if ht.stats != nil {
-		s.ctx = ht.stats.TagRPC(s.ctx, &stats.RPCTagInfo{FullMethodName: s.method})
+	for _, sh := range ht.stats {
+		s.ctx = sh.TagRPC(s.ctx, &stats.RPCTagInfo{FullMethodName: s.method})
 		inHeader := &stats.InHeader{
 			FullMethod:  s.method,
 			RemoteAddr:  ht.RemoteAddr(),
 			Compression: s.recvCompress,
 		}
-		ht.stats.HandleRPC(s.ctx, inHeader)
+		sh.HandleRPC(s.ctx, inHeader)
 	}
 	s.trReader = &transportReader{
 		reader:        &recvBufferReader{ctx: s.ctx, ctxDone: s.ctx.Done(), recv: s.buf, freeBuffer: func(*bytes.Buffer) {}},
@@ -435,7 +453,7 @@
 
 func (ht *serverHandlerTransport) IncrMsgRecv() {}
 
-func (ht *serverHandlerTransport) Drain() {
+func (ht *serverHandlerTransport) Drain(debugData string) {
 	panic("Drain() is not implemented")
 }
 
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 10b5461..326bf08 100644
--- a/vendor/google.golang.org/grpc/internal/transport/http2_client.go
+++ b/vendor/google.golang.org/grpc/internal/transport/http2_client.go
@@ -38,8 +38,11 @@
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/internal/channelz"
 	icredentials "google.golang.org/grpc/internal/credentials"
+	"google.golang.org/grpc/internal/grpclog"
+	"google.golang.org/grpc/internal/grpcsync"
 	"google.golang.org/grpc/internal/grpcutil"
 	imetadata "google.golang.org/grpc/internal/metadata"
+	istatus "google.golang.org/grpc/internal/status"
 	"google.golang.org/grpc/internal/syscall"
 	"google.golang.org/grpc/internal/transport/networktype"
 	"google.golang.org/grpc/keepalive"
@@ -57,11 +60,15 @@
 
 // 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.
-	userAgent  string
+	lastRead  int64 // Keep this field 64-bit aligned. Accessed atomically.
+	ctx       context.Context
+	cancel    context.CancelFunc
+	ctxDone   <-chan struct{} // Cache the ctx.Done() chan.
+	userAgent string
+	// address contains the resolver returned address for this transport.
+	// If the `ServerName` field is set, it takes precedence over `CallHdr.Host`
+	// passed to `NewStream`, when determining the :authority header.
+	address    resolver.Address
 	md         metadata.MD
 	conn       net.Conn // underlying communication channel
 	loopy      *loopyWriter
@@ -78,6 +85,7 @@
 	framer *framer
 	// controlBuf delivers all the control related tasks (e.g., window
 	// updates, reset streams, and various settings) to the controller.
+	// Do not access controlBuf with mu held.
 	controlBuf *controlBuffer
 	fc         *trInFlow
 	// The scheme used: https if TLS is on, http otherwise.
@@ -90,7 +98,7 @@
 	kp               keepalive.ClientParameters
 	keepaliveEnabled bool
 
-	statsHandler stats.Handler
+	statsHandlers []stats.Handler
 
 	initialWindowSize int32
 
@@ -98,17 +106,15 @@
 	maxSendHeaderListSize *uint32
 
 	bdpEst *bdpEstimator
-	// onPrefaceReceipt is a callback that client transport calls upon
-	// receiving server preface to signal that a succefull HTTP2
-	// connection was established.
-	onPrefaceReceipt func()
 
 	maxConcurrentStreams  uint32
 	streamQuota           int64
 	streamsQuotaAvailable chan struct{}
 	waitingStreams        uint32
 	nextID                uint32
+	registeredCompressors string
 
+	// Do not access controlBuf with mu held.
 	mu            sync.Mutex // guard the following variables
 	state         transportState
 	activeStreams map[uint32]*Stream
@@ -132,15 +138,15 @@
 	kpDormant bool
 
 	// Fields below are for channelz metric collection.
-	channelzID int64 // channelz unique identification number
+	channelzID *channelz.Identifier
 	czData     *channelzData
 
-	onGoAway func(GoAwayReason)
-	onClose  func()
+	onClose func(GoAwayReason)
 
 	bufferPool *bufferPool
 
 	connectionID uint64
+	logger       *grpclog.PrefixLogger
 }
 
 func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error), addr resolver.Address, useProxy bool, grpcUA string) (net.Conn, error) {
@@ -192,7 +198,7 @@
 // newHTTP2Client constructs a connected ClientTransport to addr based on HTTP2
 // and starts to receive messages on it. Non-nil error returns if construction
 // fails.
-func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onPrefaceReceipt func(), onGoAway func(GoAwayReason), onClose func()) (_ *http2Client, err error) {
+func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onClose func(GoAwayReason)) (_ *http2Client, err error) {
 	scheme := "http"
 	ctx, cancel := context.WithCancel(ctx)
 	defer func() {
@@ -212,14 +218,40 @@
 		if opts.FailOnNonTempDialError {
 			return nil, connectionErrorf(isTemporary(err), err, "transport: error while dialing: %v", err)
 		}
-		return nil, connectionErrorf(true, err, "transport: Error while dialing %v", err)
+		return nil, connectionErrorf(true, err, "transport: Error while dialing: %v", err)
 	}
+
 	// Any further errors will close the underlying connection
 	defer func(conn net.Conn) {
 		if err != nil {
 			conn.Close()
 		}
 	}(conn)
+
+	// The following defer and goroutine monitor the connectCtx for cancelation
+	// and deadline.  On context expiration, the connection is hard closed and
+	// this function will naturally fail as a result.  Otherwise, the defer
+	// waits for the goroutine to exit to prevent the context from being
+	// monitored (and to prevent the connection from ever being closed) after
+	// returning from this function.
+	ctxMonitorDone := grpcsync.NewEvent()
+	newClientCtx, newClientDone := context.WithCancel(connectCtx)
+	defer func() {
+		newClientDone()         // Awaken the goroutine below if connectCtx hasn't expired.
+		<-ctxMonitorDone.Done() // Wait for the goroutine below to exit.
+	}()
+	go func(conn net.Conn) {
+		defer ctxMonitorDone.Fire() // Signal this goroutine has exited.
+		<-newClientCtx.Done()       // Block until connectCtx expires or the defer above executes.
+		if err := connectCtx.Err(); err != nil {
+			// connectCtx expired before exiting the function.  Hard close the connection.
+			if logger.V(logLevel) {
+				logger.Infof("Aborting due to connect deadline expiring: %v", err)
+			}
+			conn.Close()
+		}
+	}(conn)
+
 	kp := opts.KeepaliveParams
 	// Validate keepalive parameters.
 	if kp.Time == 0 {
@@ -251,15 +283,7 @@
 		}
 	}
 	if transportCreds != nil {
-		rawConn := conn
-		// Pull the deadline from the connectCtx, which will be used for
-		// timeouts in the authentication protocol handshake. Can ignore the
-		// boolean as the deadline will return the zero value, which will make
-		// the conn not timeout on I/O operations.
-		deadline, _ := connectCtx.Deadline()
-		rawConn.SetDeadline(deadline)
-		conn, authInfo, err = transportCreds.ClientHandshake(connectCtx, addr.ServerName, rawConn)
-		rawConn.SetDeadline(time.Time{})
+		conn, authInfo, err = transportCreds.ClientHandshake(connectCtx, addr.ServerName, conn)
 		if err != nil {
 			return nil, connectionErrorf(isTemporary(err), err, "transport: authentication handshake failed: %v", err)
 		}
@@ -297,6 +321,8 @@
 		ctxDone:               ctx.Done(), // Cache Done chan.
 		cancel:                cancel,
 		userAgent:             opts.UserAgent,
+		registeredCompressors: grpcutil.RegisteredCompressors(),
+		address:               addr,
 		conn:                  conn,
 		remoteAddr:            conn.RemoteAddr(),
 		localAddr:             conn.LocalAddr(),
@@ -311,19 +337,20 @@
 		isSecure:              isSecure,
 		perRPCCreds:           perRPCCreds,
 		kp:                    kp,
-		statsHandler:          opts.StatsHandler,
+		statsHandlers:         opts.StatsHandlers,
 		initialWindowSize:     initialWindowSize,
-		onPrefaceReceipt:      onPrefaceReceipt,
 		nextID:                1,
 		maxConcurrentStreams:  defaultMaxStreamsClient,
 		streamQuota:           defaultMaxStreamsClient,
 		streamsQuotaAvailable: make(chan struct{}, 1),
 		czData:                new(channelzData),
-		onGoAway:              onGoAway,
-		onClose:               onClose,
 		keepaliveEnabled:      keepaliveEnabled,
 		bufferPool:            newBufferPool(),
+		onClose:               onClose,
 	}
+	t.logger = prefixLoggerForClientTransport(t)
+	// Add peer information to the http2client context.
+	t.ctx = peer.NewContext(t.ctx, t.getPeer())
 
 	if md, ok := addr.Metadata.(*metadata.MD); ok {
 		t.md = *md
@@ -341,38 +368,50 @@
 			updateFlowControl: t.updateFlowControl,
 		}
 	}
-	if t.statsHandler != nil {
-		t.ctx = t.statsHandler.TagConn(t.ctx, &stats.ConnTagInfo{
+	for _, sh := range t.statsHandlers {
+		t.ctx = sh.TagConn(t.ctx, &stats.ConnTagInfo{
 			RemoteAddr: t.remoteAddr,
 			LocalAddr:  t.localAddr,
 		})
 		connBegin := &stats.ConnBegin{
 			Client: true,
 		}
-		t.statsHandler.HandleConn(t.ctx, connBegin)
+		sh.HandleConn(t.ctx, connBegin)
 	}
-	if channelz.IsOn() {
-		t.channelzID = channelz.RegisterNormalSocket(t, opts.ChannelzParentID, fmt.Sprintf("%s -> %s", t.localAddr, t.remoteAddr))
+	t.channelzID, err = channelz.RegisterNormalSocket(t, opts.ChannelzParentID, fmt.Sprintf("%s -> %s", t.localAddr, t.remoteAddr))
+	if err != nil {
+		return nil, err
 	}
 	if t.keepaliveEnabled {
 		t.kpDormancyCond = sync.NewCond(&t.mu)
 		go t.keepalive()
 	}
-	// Start the reader goroutine for incoming message. Each transport has
-	// a dedicated goroutine which reads HTTP2 frame from network. Then it
-	// dispatches the frame to the corresponding stream entity.
-	go t.reader()
+
+	// Start the reader goroutine for incoming messages. Each transport has a
+	// dedicated goroutine which reads HTTP2 frames from the network. Then it
+	// dispatches the frame to the corresponding stream entity.  When the
+	// server preface is received, readerErrCh is closed.  If an error occurs
+	// first, an error is pushed to the channel.  This must be checked before
+	// returning from this function.
+	readerErrCh := make(chan error, 1)
+	go t.reader(readerErrCh)
+	defer func() {
+		if err == nil {
+			err = <-readerErrCh
+		}
+		if err != nil {
+			t.Close(err)
+		}
+	}()
 
 	// Send connection preface to server.
 	n, err := t.conn.Write(clientPreface)
 	if err != nil {
 		err = connectionErrorf(true, err, "transport: failed to write client preface: %v", err)
-		t.Close(err)
 		return nil, err
 	}
 	if n != len(clientPreface) {
 		err = connectionErrorf(true, nil, "transport: preface mismatch, wrote %d bytes; want %d", n, len(clientPreface))
-		t.Close(err)
 		return nil, err
 	}
 	var ss []http2.Setting
@@ -392,14 +431,12 @@
 	err = t.framer.fr.WriteSettings(ss...)
 	if err != nil {
 		err = connectionErrorf(true, err, "transport: failed to write initial settings frame: %v", err)
-		t.Close(err)
 		return nil, err
 	}
 	// Adjust the connection flow control window if needed.
 	if delta := uint32(icwz - defaultWindowSize); delta > 0 {
 		if err := t.framer.fr.WriteWindowUpdate(0, delta); err != nil {
 			err = connectionErrorf(true, err, "transport: failed to write window update: %v", err)
-			t.Close(err)
 			return nil, err
 		}
 	}
@@ -410,17 +447,8 @@
 		return nil, err
 	}
 	go func() {
-		t.loopy = newLoopyWriter(clientSide, t.framer, t.controlBuf, t.bdpEst)
-		err := t.loopy.run()
-		if err != nil {
-			if logger.V(logLevel) {
-				logger.Errorf("transport: loopyWriter.run returning. Err: %v", err)
-			}
-		}
-		// Do not close the transport.  Let reader goroutine handle it since
-		// there might be data in the buffers.
-		t.conn.Close()
-		t.controlBuf.finish()
+		t.loopy = newLoopyWriter(clientSide, t.framer, t.controlBuf, t.bdpEst, t.conn, t.logger)
+		t.loopy.run()
 		close(t.writerDone)
 	}()
 	return t, nil
@@ -466,7 +494,7 @@
 func (t *http2Client) getPeer() *peer.Peer {
 	return &peer.Peer{
 		Addr:     t.remoteAddr,
-		AuthInfo: t.authInfo,
+		AuthInfo: t.authInfo, // Can be nil
 	}
 }
 
@@ -502,9 +530,22 @@
 		headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-previous-rpc-attempts", Value: strconv.Itoa(callHdr.PreviousAttempts)})
 	}
 
+	registeredCompressors := t.registeredCompressors
 	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})
+		// Include the outgoing compressor name when compressor is not registered
+		// via encoding.RegisterCompressor. This is possible when client uses
+		// WithCompressor dial option.
+		if !grpcutil.IsCompressorNameRegistered(callHdr.SendCompress) {
+			if registeredCompressors != "" {
+				registeredCompressors += ","
+			}
+			registeredCompressors += callHdr.SendCompress
+		}
+	}
+
+	if registeredCompressors != "" {
+		headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-accept-encoding", Value: registeredCompressors})
 	}
 	if dl, ok := ctx.Deadline(); ok {
 		// Send out timeout regardless its value. The server can detect timeout context by itself.
@@ -584,7 +625,11 @@
 	for _, c := range t.perRPCCreds {
 		data, err := c.GetRequestMetadata(ctx, audience)
 		if err != nil {
-			if _, ok := status.FromError(err); ok {
+			if st, ok := status.FromError(err); ok {
+				// Restrict the code to the list allowed by gRFC A54.
+				if istatus.IsRestrictedControlPlaneCode(st) {
+					err = status.Errorf(codes.Internal, "transport: received per-RPC creds error with illegal status: %v", err)
+				}
 				return nil, err
 			}
 
@@ -613,7 +658,14 @@
 		}
 		data, err := callCreds.GetRequestMetadata(ctx, audience)
 		if err != nil {
-			return nil, status.Errorf(codes.Internal, "transport: %v", err)
+			if st, ok := status.FromError(err); ok {
+				// Restrict the code to the list allowed by gRFC A54.
+				if istatus.IsRestrictedControlPlaneCode(st) {
+					err = status.Errorf(codes.Internal, "transport: received per-RPC creds error with illegal status: %v", err)
+				}
+				return nil, err
+			}
+			return nil, status.Errorf(codes.Internal, "transport: per-RPC creds failed due to error: %v", err)
 		}
 		callAuthData = make(map[string]string, len(data))
 		for k, v := range data {
@@ -630,8 +682,8 @@
 // the wire.  However, there are two notable exceptions:
 //
 //  1. If the stream headers violate the max header list size allowed by the
-//     server.  In this case there is no reason to retry at all, as it is
-//     assumed the RPC would continue to fail on subsequent attempts.
+//     server.  It's possible this could succeed on another transport, even if
+//     it's unlikely, but do not transparently retry.
 //  2. If the credentials errored when requesting their headers.  In this case,
 //     it's possible a retry can fix the problem, but indefinitely transparently
 //     retrying is not appropriate as it is likely the credentials, if they can
@@ -639,8 +691,7 @@
 type NewStreamError struct {
 	Err error
 
-	DoNotRetry            bool
-	DoNotTransparentRetry bool
+	AllowTransparentRetry bool
 }
 
 func (e NewStreamError) Error() string {
@@ -649,11 +700,23 @@
 
 // NewStream creates a stream and registers it into the transport as "active"
 // streams.  All non-nil errors returned will be *NewStreamError.
-func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Stream, err error) {
+func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream, error) {
 	ctx = peer.NewContext(ctx, t.getPeer())
+
+	// ServerName field of the resolver returned address takes precedence over
+	// Host field of CallHdr to determine the :authority header. This is because,
+	// the ServerName field takes precedence for server authentication during
+	// TLS handshake, and the :authority header should match the value used
+	// for server authentication.
+	if t.address.ServerName != "" {
+		newCallHdr := *callHdr
+		newCallHdr.Host = t.address.ServerName
+		callHdr = &newCallHdr
+	}
+
 	headerFields, err := t.createHeaderFields(ctx, callHdr)
 	if err != nil {
-		return nil, &NewStreamError{Err: err, DoNotTransparentRetry: true}
+		return nil, &NewStreamError{Err: err, AllowTransparentRetry: false}
 	}
 	s := t.newStream(ctx, callHdr)
 	cleanup := func(err error) {
@@ -675,17 +738,13 @@
 		endStream: false,
 		initStream: func(id uint32) error {
 			t.mu.Lock()
-			if state := t.state; state != reachable {
+			// TODO: handle transport closure in loopy instead and remove this
+			// initStream is never called when transport is draining.
+			if t.state == closing {
 				t.mu.Unlock()
-				// Do a quick cleanup.
-				err := error(errStreamDrain)
-				if state == closing {
-					err = ErrConnClosing
-				}
-				cleanup(err)
-				return err
+				cleanup(ErrConnClosing)
+				return ErrConnClosing
 			}
-			t.activeStreams[id] = s
 			if channelz.IsOn() {
 				atomic.AddInt64(&t.czData.streamsStarted, 1)
 				atomic.StoreInt64(&t.czData.lastStreamCreatedTime, time.Now().UnixNano())
@@ -702,6 +761,7 @@
 	}
 	firstTry := true
 	var ch chan struct{}
+	transportDrainRequired := false
 	checkForStreamQuota := func(it interface{}) bool {
 		if t.streamQuota <= 0 { // Can go negative if server decreases it.
 			if firstTry {
@@ -717,8 +777,20 @@
 		h := it.(*headerFrame)
 		h.streamID = t.nextID
 		t.nextID += 2
+
+		// Drain client transport if nextID > MaxStreamID which signals gRPC that
+		// the connection is closed and a new one must be created for subsequent RPCs.
+		transportDrainRequired = t.nextID > MaxStreamID
+
 		s.id = h.streamID
 		s.fc = &inFlow{limit: uint32(t.initialWindowSize)}
+		t.mu.Lock()
+		if t.state == draining || t.activeStreams == nil { // Can be niled from Close().
+			t.mu.Unlock()
+			return false // Don't create a stream if the transport is already closed.
+		}
+		t.activeStreams[s.id] = s
+		t.mu.Unlock()
 		if t.streamQuota > 0 && t.waitingStreams > 0 {
 			select {
 			case t.streamsQuotaAvailable <- struct{}{}:
@@ -744,22 +816,17 @@
 	}
 	for {
 		success, err := t.controlBuf.executeAndPut(func(it interface{}) bool {
-			if !checkForStreamQuota(it) {
-				return false
-			}
-			if !checkForHeaderListSize(it) {
-				return false
-			}
-			return true
+			return checkForHeaderListSize(it) && checkForStreamQuota(it)
 		}, hdr)
 		if err != nil {
-			return nil, &NewStreamError{Err: err}
+			// Connection closed.
+			return nil, &NewStreamError{Err: err, AllowTransparentRetry: true}
 		}
 		if success {
 			break
 		}
 		if hdrListSizeErr != nil {
-			return nil, &NewStreamError{Err: hdrListSizeErr, DoNotRetry: true}
+			return nil, &NewStreamError{Err: hdrListSizeErr}
 		}
 		firstTry = false
 		select {
@@ -767,29 +834,38 @@
 		case <-ctx.Done():
 			return nil, &NewStreamError{Err: ContextErr(ctx.Err())}
 		case <-t.goAway:
-			return nil, &NewStreamError{Err: errStreamDrain}
+			return nil, &NewStreamError{Err: errStreamDrain, AllowTransparentRetry: true}
 		case <-t.ctx.Done():
-			return nil, &NewStreamError{Err: ErrConnClosing}
+			return nil, &NewStreamError{Err: ErrConnClosing, AllowTransparentRetry: true}
 		}
 	}
-	if t.statsHandler != nil {
+	if len(t.statsHandlers) != 0 {
 		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,
+		for _, sh := range t.statsHandlers {
+			// Note: The header fields are compressed with hpack after this call returns.
+			// No WireLength field is set here.
+			// Note: Creating a new stats object to prevent pollution.
+			outHeader := &stats.OutHeader{
+				Client:      true,
+				FullMethod:  callHdr.Method,
+				RemoteAddr:  t.remoteAddr,
+				LocalAddr:   t.localAddr,
+				Compression: callHdr.SendCompress,
+				Header:      header,
+			}
+			sh.HandleRPC(s.ctx, outHeader)
 		}
-		t.statsHandler.HandleRPC(s.ctx, outHeader)
+	}
+	if transportDrainRequired {
+		if t.logger.V(logLevel) {
+			t.logger.Infof("Draining transport: t.nextID > MaxStreamID")
+		}
+		t.GracefulClose()
 	}
 	return s, nil
 }
@@ -872,20 +948,21 @@
 // Close kicks off the shutdown process of the transport. This should be called
 // only once on a transport. Once it is called, the transport should not be
 // accessed any more.
-//
-// This method blocks until the addrConn that initiated this transport is
-// re-connected. This happens because t.onClose() begins reconnect logic at the
-// addrConn level and blocks until the addrConn is successfully connected.
 func (t *http2Client) Close(err error) {
 	t.mu.Lock()
-	// Make sure we only Close once.
+	// Make sure we only close once.
 	if t.state == closing {
 		t.mu.Unlock()
 		return
 	}
-	// Call t.onClose before setting the state to closing to prevent the client
-	// from attempting to create new streams ASAP.
-	t.onClose()
+	if t.logger.V(logLevel) {
+		t.logger.Infof("Closing: %v", err)
+	}
+	// Call t.onClose ASAP to prevent the client from attempting to create new
+	// streams.
+	if t.state != draining {
+		t.onClose(GoAwayInvalid)
+	}
 	t.state = closing
 	streams := t.activeStreams
 	t.activeStreams = nil
@@ -898,9 +975,7 @@
 	t.controlBuf.finish()
 	t.cancel()
 	t.conn.Close()
-	if channelz.IsOn() {
-		channelz.RemoveEntry(t.channelzID)
-	}
+	channelz.RemoveEntry(t.channelzID)
 	// Append info about previous goaways if there were any, since this may be important
 	// for understanding the root cause for this connection to be closed.
 	_, goAwayDebugMessage := t.GetGoAwayReason()
@@ -917,11 +992,11 @@
 	for _, s := range streams {
 		t.closeStream(s, err, false, http2.ErrCodeNo, st, nil, false)
 	}
-	if t.statsHandler != nil {
+	for _, sh := range t.statsHandlers {
 		connEnd := &stats.ConnEnd{
 			Client: true,
 		}
-		t.statsHandler.HandleConn(t.ctx, connEnd)
+		sh.HandleConn(t.ctx, connEnd)
 	}
 }
 
@@ -937,11 +1012,15 @@
 		t.mu.Unlock()
 		return
 	}
+	if t.logger.V(logLevel) {
+		t.logger.Infof("GracefulClose called")
+	}
+	t.onClose(GoAwayInvalid)
 	t.state = draining
 	active := len(t.activeStreams)
 	t.mu.Unlock()
 	if active == 0 {
-		t.Close(ErrConnClosing)
+		t.Close(connectionErrorf(true, nil, "no active streams left to process while draining"))
 		return
 	}
 	t.controlBuf.put(&incomingGoAway{})
@@ -1001,13 +1080,13 @@
 // for the transport and the stream based on the current bdp
 // estimation.
 func (t *http2Client) updateFlowControl(n uint32) {
-	t.mu.Lock()
-	for _, s := range t.activeStreams {
-		s.fc.newLimit(n)
-	}
-	t.mu.Unlock()
 	updateIWS := func(interface{}) bool {
 		t.initialWindowSize = int32(n)
+		t.mu.Lock()
+		for _, s := range t.activeStreams {
+			s.fc.newLimit(n)
+		}
+		t.mu.Unlock()
 		return true
 	}
 	t.controlBuf.executeAndPut(updateIWS, &outgoingWindowUpdate{streamID: 0, increment: t.fc.newLimit(n)})
@@ -1098,8 +1177,8 @@
 	}
 	statusCode, ok := http2ErrConvTab[f.ErrCode]
 	if !ok {
-		if logger.V(logLevel) {
-			logger.Warningf("transport: http2Client.handleRSTStream found no mapped gRPC status for the received http2 error %v", f.ErrCode)
+		if t.logger.V(logLevel) {
+			t.logger.Infof("Received a RST_STREAM frame with code %q, but found no mapped gRPC status", f.ErrCode)
 		}
 		statusCode = codes.Unknown
 	}
@@ -1181,10 +1260,12 @@
 		t.mu.Unlock()
 		return
 	}
-	if f.ErrCode == http2.ErrCodeEnhanceYourCalm {
-		if logger.V(logLevel) {
-			logger.Infof("Client received GoAway with http2.ErrCodeEnhanceYourCalm.")
-		}
+	if f.ErrCode == http2.ErrCodeEnhanceYourCalm && string(f.DebugData()) == "too_many_pings" {
+		// When a client receives a GOAWAY with error code ENHANCE_YOUR_CALM and debug
+		// data equal to ASCII "too_many_pings", it should log the occurrence at a log level that is
+		// enabled by default and double the configure KEEPALIVE_TIME used for new connections
+		// on that channel.
+		logger.Errorf("Client received GoAway with error code ENHANCE_YOUR_CALM and debug data equal to ASCII \"too_many_pings\".")
 	}
 	id := f.LastStreamID
 	if id > 0 && id%2 == 0 {
@@ -1213,12 +1294,14 @@
 	default:
 		t.setGoAwayReason(f)
 		close(t.goAway)
-		t.controlBuf.put(&incomingGoAway{})
+		defer t.controlBuf.put(&incomingGoAway{}) // Defer as t.mu is currently held.
 		// 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
+		if t.state != draining {
+			t.onClose(t.goAwayReason)
+			t.state = draining
+		}
 	}
 	// All streams with IDs greater than the GoAwayId
 	// and smaller than the previous GoAway ID should be killed.
@@ -1226,24 +1309,35 @@
 	if upperLimit == 0 { // This is the first GoAway Frame.
 		upperLimit = math.MaxUint32 // Kill all streams after the GoAway ID.
 	}
+
+	t.prevGoAwayID = id
+	if len(t.activeStreams) == 0 {
+		t.mu.Unlock()
+		t.Close(connectionErrorf(true, nil, "received goaway and there are no active streams"))
+		return
+	}
+
+	streamsToClose := make([]*Stream, 0)
 	for streamID, stream := range t.activeStreams {
 		if streamID > id && streamID <= upperLimit {
 			// The stream was unprocessed by the server.
-			atomic.StoreUint32(&stream.unprocessed, 1)
-			t.closeStream(stream, errStreamDrain, false, http2.ErrCodeNo, statusGoAway, nil, false)
+			if streamID > id && streamID <= upperLimit {
+				atomic.StoreUint32(&stream.unprocessed, 1)
+				streamsToClose = append(streamsToClose, stream)
+			}
 		}
 	}
-	t.prevGoAwayID = id
-	active := len(t.activeStreams)
 	t.mu.Unlock()
-	if active == 0 {
-		t.Close(connectionErrorf(true, nil, "received goaway and there are no active streams"))
+	// Called outside t.mu because closeStream can take controlBuf's mu, which
+	// could induce deadlock and is not allowed.
+	for _, stream := range streamsToClose {
+		t.closeStream(stream, errStreamDrain, false, http2.ErrCodeNo, statusGoAway, nil, false)
 	}
 }
 
 // setGoAwayReason sets the value of t.goAwayReason based
 // on the GoAway frame received.
-// It expects a lock on transport's mutext to be held by
+// It expects a lock on transport's mutex to be held by
 // the caller.
 func (t *http2Client) setGoAwayReason(f *http2.GoAwayFrame) {
 	t.goAwayReason = GoAwayNoReason
@@ -1433,7 +1527,7 @@
 		close(s.headerChan)
 	}
 
-	if t.statsHandler != nil {
+	for _, sh := range t.statsHandlers {
 		if isHeader {
 			inHeader := &stats.InHeader{
 				Client:      true,
@@ -1441,14 +1535,14 @@
 				Header:      metadata.MD(mdata).Copy(),
 				Compression: s.recvCompress,
 			}
-			t.statsHandler.HandleRPC(s.ctx, inHeader)
+			sh.HandleRPC(s.ctx, inHeader)
 		} else {
 			inTrailer := &stats.InTrailer{
 				Client:     true,
 				WireLength: int(frame.Header().Length),
 				Trailer:    metadata.MD(mdata).Copy(),
 			}
-			t.statsHandler.HandleRPC(s.ctx, inTrailer)
+			sh.HandleRPC(s.ctx, inTrailer)
 		}
 	}
 
@@ -1465,33 +1559,35 @@
 	t.closeStream(s, io.EOF, rst, http2.ErrCodeNo, statusGen, mdata, true)
 }
 
-// reader runs as a separate goroutine in charge of reading data from network
-// connection.
-//
-// TODO(zhaoq): currently one reader per transport. Investigate whether this is
-// optimal.
-// TODO(zhaoq): Check the validity of the incoming frame sequence.
-func (t *http2Client) reader() {
-	defer close(t.readerDone)
-	// Check the validity of server preface.
+// readServerPreface reads and handles the initial settings frame from the
+// server.
+func (t *http2Client) readServerPreface() error {
 	frame, err := t.framer.fr.ReadFrame()
 	if err != nil {
-		err = connectionErrorf(true, err, "error reading server preface: %v", err)
-		t.Close(err) // this kicks off resetTransport, so must be last before return
-		return
-	}
-	t.conn.SetReadDeadline(time.Time{}) // reset deadline once we get the settings frame (we didn't time out, yay!)
-	if t.keepaliveEnabled {
-		atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
+		return connectionErrorf(true, err, "error reading server preface: %v", err)
 	}
 	sf, ok := frame.(*http2.SettingsFrame)
 	if !ok {
-		// this kicks off resetTransport, so must be last before return
-		t.Close(connectionErrorf(true, nil, "initial http2 frame from server is not a settings frame: %T", frame))
+		return connectionErrorf(true, nil, "initial http2 frame from server is not a settings frame: %T", frame)
+	}
+	t.handleSettings(sf, true)
+	return nil
+}
+
+// reader verifies the server preface and reads all subsequent data from
+// network connection.  If the server preface is not read successfully, an
+// error is pushed to errCh; otherwise errCh is closed with no error.
+func (t *http2Client) reader(errCh chan<- error) {
+	defer close(t.readerDone)
+
+	if err := t.readServerPreface(); err != nil {
+		errCh <- err
 		return
 	}
-	t.onPrefaceReceipt()
-	t.handleSettings(sf, true)
+	close(errCh)
+	if t.keepaliveEnabled {
+		atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
+	}
 
 	// loop to keep reading incoming messages on this transport.
 	for {
@@ -1694,3 +1790,9 @@
 		return -2
 	}
 }
+
+func (t *http2Client) stateForTesting() transportState {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	return t.state
+}
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 2c6eaf0..79e86ba 100644
--- a/vendor/google.golang.org/grpc/internal/transport/http2_server.go
+++ b/vendor/google.golang.org/grpc/internal/transport/http2_server.go
@@ -35,12 +35,16 @@
 	"github.com/golang/protobuf/proto"
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
+	"google.golang.org/grpc/internal/grpclog"
 	"google.golang.org/grpc/internal/grpcutil"
+	"google.golang.org/grpc/internal/pretty"
+	"google.golang.org/grpc/internal/syscall"
 
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/grpcrand"
+	"google.golang.org/grpc/internal/grpcsync"
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/peer"
@@ -52,10 +56,10 @@
 var (
 	// ErrIllegalHeaderWrite indicates that setting header is illegal because of
 	// the stream's state.
-	ErrIllegalHeaderWrite = errors.New("transport: the stream is done or WriteHeader was already called")
+	ErrIllegalHeaderWrite = status.Error(codes.Internal, "transport: SendHeader called multiple times")
 	// 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")
+	ErrHeaderListSizeLimitViolation = status.Error(codes.Internal, "transport: trying to send header list size larger than the limit set by peer")
 )
 
 // serverConnectionCounter counts the number of connections a server has seen
@@ -82,7 +86,7 @@
 	// updates, reset streams, and various settings) to the controller.
 	controlBuf *controlBuffer
 	fc         *trInFlow
-	stats      stats.Handler
+	stats      []stats.Handler
 	// Keepalive and max-age parameters for the server.
 	kp keepalive.ServerParameters
 	// Keepalive enforcement policy.
@@ -101,13 +105,13 @@
 
 	mu sync.Mutex // guard the following
 
-	// drainChan is initialized when Drain() is called the first time.
-	// After which the server writes out the first GoAway(with ID 2^31-1) frame.
-	// Then an independent goroutine will be launched to later send the second GoAway.
-	// During this time we don't want to write another first GoAway(with ID 2^31 -1) frame.
-	// Thus call to Drain() will be a no-op if drainChan is already initialized since draining is
-	// already underway.
-	drainChan     chan struct{}
+	// drainEvent is initialized when Drain() is called the first time. After
+	// which the server writes out the first GoAway(with ID 2^31-1) frame. Then
+	// an independent goroutine will be launched to later send the second
+	// GoAway. During this time we don't want to write another first GoAway(with
+	// ID 2^31 -1) frame. Thus call to Drain() will be a no-op if drainEvent is
+	// already initialized since draining is already underway.
+	drainEvent    *grpcsync.Event
 	state         transportState
 	activeStreams map[uint32]*Stream
 	// idle is the time instant when the connection went idle.
@@ -117,7 +121,7 @@
 	idle time.Time
 
 	// Fields below are for channelz metric collection.
-	channelzID int64 // channelz unique identification number
+	channelzID *channelz.Identifier
 	czData     *channelzData
 	bufferPool *bufferPool
 
@@ -127,6 +131,8 @@
 	// This lock may not be taken if mu is already held.
 	maxStreamMu sync.Mutex
 	maxStreamID uint32 // max stream ID ever seen
+
+	logger *grpclog.PrefixLogger
 }
 
 // NewServerTransport creates a http2 transport with conn and configuration
@@ -231,6 +237,11 @@
 	if kp.Timeout == 0 {
 		kp.Timeout = defaultServerKeepaliveTimeout
 	}
+	if kp.Time != infinity {
+		if err = syscall.SetTCPUserTimeout(conn, kp.Timeout); err != nil {
+			return nil, connectionErrorf(false, err, "transport: failed to set TCP_USER_TIMEOUT: %v", err)
+		}
+	}
 	kep := config.KeepalivePolicy
 	if kep.MinTime == 0 {
 		kep.MinTime = defaultKeepalivePolicyMinTime
@@ -252,7 +263,7 @@
 		fc:                &trInFlow{limit: uint32(icwz)},
 		state:             reachable,
 		activeStreams:     make(map[uint32]*Stream),
-		stats:             config.StatsHandler,
+		stats:             config.StatsHandlers,
 		kp:                kp,
 		idle:              time.Now(),
 		kep:               kep,
@@ -260,6 +271,10 @@
 		czData:            new(channelzData),
 		bufferPool:        newBufferPool(),
 	}
+	t.logger = prefixLoggerForServerTransport(t)
+	// Add peer information to the http2server context.
+	t.ctx = peer.NewContext(t.ctx, t.getPeer())
+
 	t.controlBuf = newControlBuffer(t.done)
 	if dynamicWindow {
 		t.bdpEst = &bdpEstimator{
@@ -267,25 +282,25 @@
 			updateFlowControl: t.updateFlowControl,
 		}
 	}
-	if t.stats != nil {
-		t.ctx = t.stats.TagConn(t.ctx, &stats.ConnTagInfo{
+	for _, sh := range t.stats {
+		t.ctx = sh.TagConn(t.ctx, &stats.ConnTagInfo{
 			RemoteAddr: t.remoteAddr,
 			LocalAddr:  t.localAddr,
 		})
 		connBegin := &stats.ConnBegin{}
-		t.stats.HandleConn(t.ctx, connBegin)
+		sh.HandleConn(t.ctx, connBegin)
 	}
-	if channelz.IsOn() {
-		t.channelzID = channelz.RegisterNormalSocket(t, config.ChannelzParentID, fmt.Sprintf("%s -> %s", t.remoteAddr, t.localAddr))
+	t.channelzID, err = channelz.RegisterNormalSocket(t, config.ChannelzParentID, fmt.Sprintf("%s -> %s", t.remoteAddr, t.localAddr))
+	if err != nil {
+		return nil, err
 	}
 
 	t.connectionID = atomic.AddUint64(&serverConnectionCounter, 1)
-
 	t.framer.writer.Flush()
 
 	defer func() {
 		if err != nil {
-			t.Close()
+			t.Close(err)
 		}
 	}()
 
@@ -321,23 +336,18 @@
 	t.handleSettings(sf)
 
 	go func() {
-		t.loopy = newLoopyWriter(serverSide, t.framer, t.controlBuf, t.bdpEst)
+		t.loopy = newLoopyWriter(serverSide, t.framer, t.controlBuf, t.bdpEst, t.conn, t.logger)
 		t.loopy.ssGoAwayHandler = t.outgoingGoAwayHandler
-		if err := t.loopy.run(); err != nil {
-			if logger.V(logLevel) {
-				logger.Errorf("transport: loopyWriter.run returning. Err: %v", err)
-			}
-		}
-		t.conn.Close()
-		t.controlBuf.finish()
+		t.loopy.run()
 		close(t.writerDone)
 	}()
 	go t.keepalive()
 	return t, nil
 }
 
-// operateHeader takes action on the decoded headers.
-func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(*Stream), traceCtx func(context.Context, string) context.Context) (fatal bool) {
+// operateHeaders takes action on the decoded headers. Returns an error if fatal
+// error encountered and transport needs to close, otherwise returns nil.
+func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(*Stream), traceCtx func(context.Context, string) context.Context) error {
 	// Acquire max stream ID lock for entire duration
 	t.maxStreamMu.Lock()
 	defer t.maxStreamMu.Unlock()
@@ -353,15 +363,12 @@
 			rstCode:  http2.ErrCodeFrameSize,
 			onWrite:  func() {},
 		})
-		return false
+		return nil
 	}
 
 	if streamID%2 != 1 || streamID <= t.maxStreamID {
 		// illegal gRPC stream id.
-		if logger.V(logLevel) {
-			logger.Errorf("transport: http2Server.HandleStreams received an illegal stream id: %v", streamID)
-		}
-		return true
+		return fmt.Errorf("received an illegal stream id: %v. headers frame: %+v", streamID, frame)
 	}
 	t.maxStreamID = streamID
 
@@ -373,13 +380,14 @@
 		fc:  &inFlow{limit: uint32(t.initialWindowSize)},
 	}
 	var (
-		// If a gRPC Response-Headers has already been received, then it means
-		// that the peer is speaking gRPC and we are in gRPC mode.
-		isGRPC     = false
-		mdata      = make(map[string][]string)
-		httpMethod string
-		// headerError is set if an error is encountered while parsing the headers
-		headerError bool
+		// if false, content-type was missing or invalid
+		isGRPC      = false
+		contentType = ""
+		mdata       = make(metadata.MD, len(frame.Fields))
+		httpMethod  string
+		// these are set if an error is encountered while parsing the headers
+		protocolError bool
+		headerError   *status.Status
 
 		timeoutSet bool
 		timeout    time.Duration
@@ -390,11 +398,23 @@
 		case "content-type":
 			contentSubtype, validContentType := grpcutil.ContentSubtype(hf.Value)
 			if !validContentType {
+				contentType = hf.Value
 				break
 			}
 			mdata[hf.Name] = append(mdata[hf.Name], hf.Value)
 			s.contentSubtype = contentSubtype
 			isGRPC = true
+
+		case "grpc-accept-encoding":
+			mdata[hf.Name] = append(mdata[hf.Name], hf.Value)
+			if hf.Value == "" {
+				continue
+			}
+			compressors := hf.Value
+			if s.clientAdvertisedCompressors != "" {
+				compressors = s.clientAdvertisedCompressors + "," + compressors
+			}
+			s.clientAdvertisedCompressors = compressors
 		case "grpc-encoding":
 			s.recvCompress = hf.Value
 		case ":method":
@@ -405,23 +425,23 @@
 			timeoutSet = true
 			var err error
 			if timeout, err = decodeTimeout(hf.Value); err != nil {
-				headerError = true
+				headerError = status.Newf(codes.Internal, "malformed grpc-timeout: %v", err)
 			}
 		// "Transports must consider requests containing the Connection header
 		// as malformed." - A41
 		case "connection":
-			if logger.V(logLevel) {
-				logger.Errorf("transport: http2Server.operateHeaders parsed a :connection header which makes a request malformed as per the HTTP/2 spec")
+			if t.logger.V(logLevel) {
+				t.logger.Infof("Received a HEADERS frame with a :connection header which makes the request malformed, as per the HTTP/2 spec")
 			}
-			headerError = true
+			protocolError = true
 		default:
 			if isReservedHeader(hf.Name) && !isWhitelistedHeader(hf.Name) {
 				break
 			}
 			v, err := decodeMetadataHeader(hf.Name, hf.Value)
 			if err != nil {
-				headerError = true
-				logger.Warningf("Failed to decode metadata header (%q, %q): %v", hf.Name, hf.Value, err)
+				headerError = status.Newf(codes.Internal, "malformed binary metadata %q in header %q: %v", hf.Value, hf.Name, err)
+				t.logger.Warningf("Failed to decode metadata header (%q, %q): %v", hf.Name, hf.Value, err)
 				break
 			}
 			mdata[hf.Name] = append(mdata[hf.Name], v)
@@ -435,26 +455,47 @@
 	// error, this takes precedence over a client not speaking gRPC.
 	if len(mdata[":authority"]) > 1 || len(mdata["host"]) > 1 {
 		errMsg := fmt.Sprintf("num values of :authority: %v, num values of host: %v, both must only have 1 value as per HTTP/2 spec", len(mdata[":authority"]), len(mdata["host"]))
-		if logger.V(logLevel) {
-			logger.Errorf("transport: %v", errMsg)
+		if t.logger.V(logLevel) {
+			t.logger.Infof("Aborting the stream early: %v", errMsg)
 		}
 		t.controlBuf.put(&earlyAbortStream{
-			httpStatus:     400,
+			httpStatus:     http.StatusBadRequest,
 			streamID:       streamID,
 			contentSubtype: s.contentSubtype,
 			status:         status.New(codes.Internal, errMsg),
+			rst:            !frame.StreamEnded(),
 		})
-		return false
+		return nil
 	}
 
-	if !isGRPC || headerError {
+	if protocolError {
 		t.controlBuf.put(&cleanupStream{
 			streamID: streamID,
 			rst:      true,
 			rstCode:  http2.ErrCodeProtocol,
 			onWrite:  func() {},
 		})
-		return false
+		return nil
+	}
+	if !isGRPC {
+		t.controlBuf.put(&earlyAbortStream{
+			httpStatus:     http.StatusUnsupportedMediaType,
+			streamID:       streamID,
+			contentSubtype: s.contentSubtype,
+			status:         status.Newf(codes.InvalidArgument, "invalid gRPC request content-type %q", contentType),
+			rst:            !frame.StreamEnded(),
+		})
+		return nil
+	}
+	if headerError != nil {
+		t.controlBuf.put(&earlyAbortStream{
+			httpStatus:     http.StatusBadRequest,
+			streamID:       streamID,
+			contentSubtype: s.contentSubtype,
+			status:         headerError,
+			rst:            !frame.StreamEnded(),
+		})
+		return nil
 	}
 
 	// "If :authority is missing, Host must be renamed to :authority." - A41
@@ -479,14 +520,7 @@
 	} else {
 		s.ctx, s.cancel = context.WithCancel(t.ctx)
 	}
-	pr := &peer.Peer{
-		Addr: t.remoteAddr,
-	}
-	// Attach Auth info if there is any.
-	if t.authInfo != nil {
-		pr.AuthInfo = t.authInfo
-	}
-	s.ctx = peer.NewContext(s.ctx, pr)
+
 	// Attach the received metadata to the context.
 	if len(mdata) > 0 {
 		s.ctx = metadata.NewIncomingContext(s.ctx, mdata)
@@ -501,7 +535,7 @@
 	if t.state != reachable {
 		t.mu.Unlock()
 		s.cancel()
-		return false
+		return nil
 	}
 	if uint32(len(t.activeStreams)) >= t.maxStreams {
 		t.mu.Unlock()
@@ -512,28 +546,30 @@
 			onWrite:  func() {},
 		})
 		s.cancel()
-		return false
+		return nil
 	}
 	if httpMethod != http.MethodPost {
 		t.mu.Unlock()
-		if logger.V(logLevel) {
-			logger.Infof("transport: http2Server.operateHeaders parsed a :method field: %v which should be POST", httpMethod)
+		errMsg := fmt.Sprintf("Received a HEADERS frame with :method %q which should be POST", httpMethod)
+		if t.logger.V(logLevel) {
+			t.logger.Infof("Aborting the stream early: %v", errMsg)
 		}
-		t.controlBuf.put(&cleanupStream{
-			streamID: streamID,
-			rst:      true,
-			rstCode:  http2.ErrCodeProtocol,
-			onWrite:  func() {},
+		t.controlBuf.put(&earlyAbortStream{
+			httpStatus:     405,
+			streamID:       streamID,
+			contentSubtype: s.contentSubtype,
+			status:         status.New(codes.Internal, errMsg),
+			rst:            !frame.StreamEnded(),
 		})
 		s.cancel()
-		return false
+		return nil
 	}
 	if t.inTapHandle != nil {
 		var err error
 		if s.ctx, err = t.inTapHandle(s.ctx, &tap.Info{FullMethodName: s.method}); err != nil {
 			t.mu.Unlock()
-			if logger.V(logLevel) {
-				logger.Infof("transport: http2Server.operateHeaders got an error from InTapHandle: %v", err)
+			if t.logger.V(logLevel) {
+				t.logger.Infof("Aborting the stream early due to InTapHandle failure: %v", err)
 			}
 			stat, ok := status.FromError(err)
 			if !ok {
@@ -544,8 +580,9 @@
 				streamID:       s.id,
 				contentSubtype: s.contentSubtype,
 				status:         stat,
+				rst:            !frame.StreamEnded(),
 			})
-			return false
+			return nil
 		}
 	}
 	t.activeStreams[streamID] = s
@@ -561,17 +598,17 @@
 		t.adjustWindow(s, uint32(n))
 	}
 	s.ctx = traceCtx(s.ctx, s.method)
-	if t.stats != nil {
-		s.ctx = t.stats.TagRPC(s.ctx, &stats.RPCTagInfo{FullMethodName: s.method})
+	for _, sh := range t.stats {
+		s.ctx = sh.TagRPC(s.ctx, &stats.RPCTagInfo{FullMethodName: s.method})
 		inHeader := &stats.InHeader{
 			FullMethod:  s.method,
 			RemoteAddr:  t.remoteAddr,
 			LocalAddr:   t.localAddr,
 			Compression: s.recvCompress,
 			WireLength:  int(frame.Header().Length),
-			Header:      metadata.MD(mdata).Copy(),
+			Header:      mdata.Copy(),
 		}
-		t.stats.HandleRPC(s.ctx, inHeader)
+		sh.HandleRPC(s.ctx, inHeader)
 	}
 	s.ctxDone = s.ctx.Done()
 	s.wq = newWriteQuota(defaultWriteQuota, s.ctxDone)
@@ -592,7 +629,7 @@
 		wq:       s.wq,
 	})
 	handle(s)
-	return false
+	return nil
 }
 
 // HandleStreams receives incoming streams using the given handler. This is
@@ -606,8 +643,8 @@
 		atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
 		if err != nil {
 			if se, ok := err.(http2.StreamError); ok {
-				if logger.V(logLevel) {
-					logger.Warningf("transport: http2Server.HandleStreams encountered http2.StreamError: %v", se)
+				if t.logger.V(logLevel) {
+					t.logger.Warningf("Encountered http2.StreamError: %v", se)
 				}
 				t.mu.Lock()
 				s := t.activeStreams[se.StreamID]
@@ -625,19 +662,16 @@
 				continue
 			}
 			if err == io.EOF || err == io.ErrUnexpectedEOF {
-				t.Close()
+				t.Close(err)
 				return
 			}
-			if logger.V(logLevel) {
-				logger.Warningf("transport: http2Server.HandleStreams failed to read frame: %v", err)
-			}
-			t.Close()
+			t.Close(err)
 			return
 		}
 		switch frame := frame.(type) {
 		case *http2.MetaHeadersFrame:
-			if t.operateHeaders(frame, handle, traceCtx) {
-				t.Close()
+			if err := t.operateHeaders(frame, handle, traceCtx); err != nil {
+				t.Close(err)
 				break
 			}
 		case *http2.DataFrame:
@@ -653,8 +687,8 @@
 		case *http2.GoAwayFrame:
 			// TODO: Handle GoAway from the client appropriately.
 		default:
-			if logger.V(logLevel) {
-				logger.Errorf("transport: http2Server.HandleStreams found unhandled frame type %v.", frame)
+			if t.logger.V(logLevel) {
+				t.logger.Infof("Received unsupported frame type %T", frame)
 			}
 		}
 	}
@@ -838,8 +872,8 @@
 
 func (t *http2Server) handlePing(f *http2.PingFrame) {
 	if f.IsAck() {
-		if f.Data == goAwayPing.data && t.drainChan != nil {
-			close(t.drainChan)
+		if f.Data == goAwayPing.data && t.drainEvent != nil {
+			t.drainEvent.Fire()
 			return
 		}
 		// Maybe it's a BDP ping.
@@ -881,10 +915,7 @@
 
 	if t.pingStrikes > maxPingStrikes {
 		// Send goaway and close the connection.
-		if logger.V(logLevel) {
-			logger.Errorf("transport: Got too many pings from the client, closing the connection.")
-		}
-		t.controlBuf.put(&goAway{code: http2.ErrCodeEnhanceYourCalm, debugData: []byte("too_many_pings"), closeConn: true})
+		t.controlBuf.put(&goAway{code: http2.ErrCodeEnhanceYourCalm, debugData: []byte("too_many_pings"), closeConn: errors.New("got too many pings from the client")})
 	}
 }
 
@@ -916,8 +947,8 @@
 	var sz int64
 	for _, f := range hdrFrame.hf {
 		if sz += int64(f.Size()); sz > int64(*t.maxSendHeaderListSize) {
-			if logger.V(logLevel) {
-				logger.Errorf("header list size to send violates the maximum size (%d bytes) set by client", *t.maxSendHeaderListSize)
+			if t.logger.V(logLevel) {
+				t.logger.Infof("Header list size to send violates the maximum size (%d bytes) set by client", *t.maxSendHeaderListSize)
 			}
 			return false
 		}
@@ -925,12 +956,27 @@
 	return true
 }
 
+func (t *http2Server) streamContextErr(s *Stream) error {
+	select {
+	case <-t.done:
+		return ErrConnClosing
+	default:
+	}
+	return ContextErr(s.ctx.Err())
+}
+
 // 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 {
+	s.hdrMu.Lock()
+	defer s.hdrMu.Unlock()
+	if s.getState() == streamDone {
+		return t.streamContextErr(s)
+	}
+
+	if s.updateHeaderSent() {
 		return ErrIllegalHeaderWrite
 	}
-	s.hdrMu.Lock()
+
 	if md.Len() > 0 {
 		if s.header.Len() > 0 {
 			s.header = metadata.Join(s.header, md)
@@ -939,10 +985,8 @@
 		}
 	}
 	if err := t.writeHeaderLocked(s); err != nil {
-		s.hdrMu.Unlock()
-		return err
+		return status.Convert(err).Err()
 	}
-	s.hdrMu.Unlock()
 	return nil
 }
 
@@ -973,14 +1017,14 @@
 		t.closeStream(s, true, http2.ErrCodeInternal, false)
 		return ErrHeaderListSizeLimitViolation
 	}
-	if t.stats != nil {
+	for _, sh := range t.stats {
 		// 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,
 		}
-		t.stats.HandleRPC(s.Context(), outHeader)
+		sh.HandleRPC(s.Context(), outHeader)
 	}
 	return nil
 }
@@ -990,17 +1034,19 @@
 // TODO(zhaoq): Now it indicates the end of entire stream. Revisit if early
 // OK is adopted.
 func (t *http2Server) WriteStatus(s *Stream, st *status.Status) error {
+	s.hdrMu.Lock()
+	defer s.hdrMu.Unlock()
+
 	if s.getState() == streamDone {
 		return nil
 	}
-	s.hdrMu.Lock()
+
 	// 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.
 	headerFields := make([]hpack.HeaderField, 0, 2) // grpc-status and grpc-message will be there if none else.
 	if !s.updateHeaderSent() {                      // No headers have been sent.
 		if len(s.header) > 0 { // Send a separate header frame.
 			if err := t.writeHeaderLocked(s); err != nil {
-				s.hdrMu.Unlock()
 				return err
 			}
 		} else { // Send a trailer only response.
@@ -1015,7 +1061,7 @@
 		stBytes, err := proto.Marshal(p)
 		if err != nil {
 			// TODO: return error instead, when callers are able to handle it.
-			logger.Errorf("transport: failed to marshal rpc status: %v, error: %v", p, err)
+			t.logger.Errorf("Failed to marshal rpc status: %s, error: %v", pretty.ToJSON(p), err)
 		} else {
 			headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-status-details-bin", Value: encodeBinHeader(stBytes)})
 		}
@@ -1029,7 +1075,7 @@
 		endStream: true,
 		onWrite:   t.setResetPingStrikes,
 	}
-	s.hdrMu.Unlock()
+
 	success, err := t.controlBuf.execute(t.checkForHeaderListSize, trailingHeader)
 	if !success {
 		if err != nil {
@@ -1041,10 +1087,10 @@
 	// Send a RST_STREAM after the trailers if the client has not already half-closed.
 	rst := s.getState() == streamActive
 	t.finishStream(s, rst, http2.ErrCodeNo, trailingHeader, true)
-	if t.stats != nil {
+	for _, sh := range t.stats {
 		// 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{
+		sh.HandleRPC(s.Context(), &stats.OutTrailer{
 			Trailer: s.trailer.Copy(),
 		})
 	}
@@ -1056,23 +1102,12 @@
 func (t *http2Server) Write(s *Stream, hdr []byte, data []byte, opts *Options) error {
 	if !s.isHeaderSent() { // Headers haven't been written yet.
 		if err := t.WriteHeader(s, nil); err != nil {
-			if _, ok := err.(ConnectionError); ok {
-				return err
-			}
-			// TODO(mmukhi, dfawley): Make sure this is the right code to return.
-			return status.Errorf(codes.Internal, "transport: %v", err)
+			return err
 		}
 	} else {
 		// Writing headers checks for this condition.
 		if s.getState() == streamDone {
-			// TODO(mmukhi, dfawley): Should the server write also return io.EOF?
-			s.cancel()
-			select {
-			case <-t.done:
-				return ErrConnClosing
-			default:
-			}
-			return ContextErr(s.ctx.Err())
+			return t.streamContextErr(s)
 		}
 	}
 	df := &dataFrame{
@@ -1082,12 +1117,7 @@
 		onEachWrite: t.setResetPingStrikes,
 	}
 	if err := s.wq.get(int32(len(hdr) + len(data))); err != nil {
-		select {
-		case <-t.done:
-			return ErrConnClosing
-		default:
-		}
-		return ContextErr(s.ctx.Err())
+		return t.streamContextErr(s)
 	}
 	return t.controlBuf.put(df)
 }
@@ -1136,20 +1166,20 @@
 			if val <= 0 {
 				// The connection has been idle for a duration of keepalive.MaxConnectionIdle or more.
 				// Gracefully close the connection.
-				t.Drain()
+				t.Drain("max_idle")
 				return
 			}
 			idleTimer.Reset(val)
 		case <-ageTimer.C:
-			t.Drain()
+			t.Drain("max_age")
 			ageTimer.Reset(t.kp.MaxConnectionAgeGrace)
 			select {
 			case <-ageTimer.C:
 				// Close the connection after grace period.
-				if logger.V(logLevel) {
-					logger.Infof("transport: closing server transport due to maximum connection age.")
+				if t.logger.V(logLevel) {
+					t.logger.Infof("Closing server transport due to maximum connection age")
 				}
-				t.Close()
+				t.controlBuf.put(closeConnection{})
 			case <-t.done:
 			}
 			return
@@ -1165,10 +1195,7 @@
 				continue
 			}
 			if outstandingPing && kpTimeoutLeft <= 0 {
-				if logger.V(logLevel) {
-					logger.Infof("transport: closing server transport due to idleness.")
-				}
-				t.Close()
+				t.Close(fmt.Errorf("keepalive ping not acked within timeout %s", t.kp.Time))
 				return
 			}
 			if !outstandingPing {
@@ -1195,40 +1222,37 @@
 // Close starts shutting down the http2Server transport.
 // TODO(zhaoq): Now the destruction is not blocked on any pending streams. This
 // could cause some resource issue. Revisit this later.
-func (t *http2Server) Close() {
+func (t *http2Server) Close(err error) {
 	t.mu.Lock()
 	if t.state == closing {
 		t.mu.Unlock()
 		return
 	}
+	if t.logger.V(logLevel) {
+		t.logger.Infof("Closing: %v", err)
+	}
 	t.state = closing
 	streams := t.activeStreams
 	t.activeStreams = nil
 	t.mu.Unlock()
 	t.controlBuf.finish()
 	close(t.done)
-	if err := t.conn.Close(); err != nil && logger.V(logLevel) {
-		logger.Infof("transport: error closing conn during Close: %v", err)
+	if err := t.conn.Close(); err != nil && t.logger.V(logLevel) {
+		t.logger.Infof("Error closing underlying net.Conn during Close: %v", err)
 	}
-	if channelz.IsOn() {
-		channelz.RemoveEntry(t.channelzID)
-	}
+	channelz.RemoveEntry(t.channelzID)
 	// Cancel all active streams.
 	for _, s := range streams {
 		s.cancel()
 	}
-	if t.stats != nil {
+	for _, sh := range t.stats {
 		connEnd := &stats.ConnEnd{}
-		t.stats.HandleConn(t.ctx, connEnd)
+		sh.HandleConn(t.ctx, connEnd)
 	}
 }
 
 // deleteStream deletes the stream s from transport's active streams.
 func (t *http2Server) deleteStream(s *Stream, eosReceived bool) {
-	// In case stream sending and receiving are invoked in separate
-	// goroutines (e.g., bi-directional streaming), cancel needs to be
-	// called to interrupt the potential blocking on other goroutines.
-	s.cancel()
 
 	t.mu.Lock()
 	if _, ok := t.activeStreams[s.id]; ok {
@@ -1250,6 +1274,11 @@
 
 // finishStream closes the stream and puts the trailing headerFrame into controlbuf.
 func (t *http2Server) finishStream(s *Stream, rst bool, rstCode http2.ErrCode, hdr *headerFrame, eosReceived bool) {
+	// In case stream sending and receiving are invoked in separate
+	// goroutines (e.g., bi-directional streaming), cancel needs to be
+	// called to interrupt the potential blocking on other goroutines.
+	s.cancel()
+
 	oldState := s.swapState(streamDone)
 	if oldState == streamDone {
 		// If the stream was already done, return.
@@ -1269,6 +1298,11 @@
 
 // closeStream clears the footprint of a stream when the stream is not needed any more.
 func (t *http2Server) closeStream(s *Stream, rst bool, rstCode http2.ErrCode, eosReceived bool) {
+	// In case stream sending and receiving are invoked in separate
+	// goroutines (e.g., bi-directional streaming), cancel needs to be
+	// called to interrupt the potential blocking on other goroutines.
+	s.cancel()
+
 	s.swapState(streamDone)
 	t.deleteStream(s, eosReceived)
 
@@ -1284,14 +1318,14 @@
 	return t.remoteAddr
 }
 
-func (t *http2Server) Drain() {
+func (t *http2Server) Drain(debugData string) {
 	t.mu.Lock()
 	defer t.mu.Unlock()
-	if t.drainChan != nil {
+	if t.drainEvent != nil {
 		return
 	}
-	t.drainChan = make(chan struct{})
-	t.controlBuf.put(&goAway{code: http2.ErrCodeNo, debugData: []byte{}, headsUp: true})
+	t.drainEvent = grpcsync.NewEvent()
+	t.controlBuf.put(&goAway{code: http2.ErrCodeNo, debugData: []byte(debugData), headsUp: true})
 }
 
 var goAwayPing = &ping{data: [8]byte{1, 6, 1, 8, 0, 3, 3, 9}}
@@ -1311,19 +1345,17 @@
 		// Stop accepting more streams now.
 		t.state = draining
 		sid := t.maxStreamID
+		retErr := g.closeConn
 		if len(t.activeStreams) == 0 {
-			g.closeConn = true
+			retErr = errors.New("second GOAWAY written and no active streams left to process")
 		}
 		t.mu.Unlock()
 		t.maxStreamMu.Unlock()
 		if err := t.framer.fr.WriteGoAway(sid, g.code, g.debugData); err != nil {
 			return false, err
 		}
-		if g.closeConn {
-			// Abruptly close the connection following the GoAway (via
-			// loopywriter).  But flush out what's inside the buffer first.
-			t.framer.writer.Flush()
-			return false, fmt.Errorf("transport: Connection closing")
+		if retErr != nil {
+			return false, retErr
 		}
 		return true, nil
 	}
@@ -1335,7 +1367,7 @@
 	// originated before the GoAway reaches the client.
 	// After getting the ack or timer expiration send out another GoAway this
 	// time with an ID of the max stream server intends to process.
-	if err := t.framer.fr.WriteGoAway(math.MaxUint32, http2.ErrCodeNo, []byte{}); err != nil {
+	if err := t.framer.fr.WriteGoAway(math.MaxUint32, http2.ErrCodeNo, g.debugData); err != nil {
 		return false, err
 	}
 	if err := t.framer.fr.WritePing(false, goAwayPing.data); err != nil {
@@ -1345,7 +1377,7 @@
 		timer := time.NewTimer(time.Minute)
 		defer timer.Stop()
 		select {
-		case <-t.drainChan:
+		case <-t.drainEvent.Done():
 		case <-timer.C:
 		case <-t.done:
 			return
@@ -1404,6 +1436,13 @@
 	}
 }
 
+func (t *http2Server) getPeer() *peer.Peer {
+	return &peer.Peer{
+		Addr:     t.remoteAddr,
+		AuthInfo: t.authInfo, // Can be nil
+	}
+}
+
 func getJitter(v time.Duration) time.Duration {
 	if v == infinity {
 		return 0
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 d8247bc..19cbb18 100644
--- a/vendor/google.golang.org/grpc/internal/transport/http_util.go
+++ b/vendor/google.golang.org/grpc/internal/transport/http_util.go
@@ -20,8 +20,8 @@
 
 import (
 	"bufio"
-	"bytes"
 	"encoding/base64"
+	"errors"
 	"fmt"
 	"io"
 	"math"
@@ -38,21 +38,14 @@
 	"golang.org/x/net/http2/hpack"
 	spb "google.golang.org/genproto/googleapis/rpc/status"
 	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/grpclog"
 	"google.golang.org/grpc/status"
 )
 
 const (
 	// http2MaxFrameLen specifies the max length of a HTTP2 frame.
 	http2MaxFrameLen = 16384 // 16KB frame
-	// http://http2.github.io/http2-spec/#SettingValues
+	// https://httpwg.org/specs/rfc7540.html#SettingValues
 	http2InitHeaderTableSize = 4096
-	// baseContentType is the base content-type for gRPC.  This is a valid
-	// content-type on it's own, but can also include a content-subtype such as
-	// "proto" as a suffix after "+" or ";".  See
-	// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
-	// for more details.
-
 )
 
 var (
@@ -92,7 +85,6 @@
 		// 504 Gateway timeout - UNAVAILABLE.
 		http.StatusGatewayTimeout: codes.Unavailable,
 	}
-	logger = grpclog.Component("transport")
 )
 
 // isReservedHeader checks whether hdr belongs to HTTP2 headers
@@ -257,13 +249,13 @@
 }
 
 func encodeGrpcMessageUnchecked(msg string) string {
-	var buf bytes.Buffer
+	var sb strings.Builder
 	for len(msg) > 0 {
 		r, size := utf8.DecodeRuneInString(msg)
 		for _, b := range []byte(string(r)) {
 			if size > 1 {
 				// If size > 1, r is not ascii. Always do percent encoding.
-				buf.WriteString(fmt.Sprintf("%%%02X", b))
+				fmt.Fprintf(&sb, "%%%02X", b)
 				continue
 			}
 
@@ -272,14 +264,14 @@
 			//
 			// fmt.Sprintf("%%%02X", utf8.RuneError) gives "%FFFD".
 			if b >= spaceByte && b <= tildeByte && b != percentByte {
-				buf.WriteByte(b)
+				sb.WriteByte(b)
 			} else {
-				buf.WriteString(fmt.Sprintf("%%%02X", b))
+				fmt.Fprintf(&sb, "%%%02X", b)
 			}
 		}
 		msg = msg[size:]
 	}
-	return buf.String()
+	return sb.String()
 }
 
 // decodeGrpcMessage decodes the msg encoded by encodeGrpcMessage.
@@ -297,23 +289,23 @@
 }
 
 func decodeGrpcMessageUnchecked(msg string) string {
-	var buf bytes.Buffer
+	var sb strings.Builder
 	lenMsg := len(msg)
 	for i := 0; i < lenMsg; i++ {
 		c := msg[i]
 		if c == percentByte && i+2 < lenMsg {
 			parsed, err := strconv.ParseUint(msg[i+1:i+3], 16, 8)
 			if err != nil {
-				buf.WriteByte(c)
+				sb.WriteByte(c)
 			} else {
-				buf.WriteByte(byte(parsed))
+				sb.WriteByte(byte(parsed))
 				i += 2
 			}
 		} else {
-			buf.WriteByte(c)
+			sb.WriteByte(c)
 		}
 	}
-	return buf.String()
+	return sb.String()
 }
 
 type bufWriter struct {
@@ -322,8 +314,6 @@
 	batchSize int
 	conn      net.Conn
 	err       error
-
-	onFlush func()
 }
 
 func newBufWriter(conn net.Conn, batchSize int) *bufWriter {
@@ -339,7 +329,8 @@
 		return 0, w.err
 	}
 	if w.batchSize == 0 { // Buffer has been disabled.
-		return w.conn.Write(b)
+		n, err = w.conn.Write(b)
+		return n, toIOError(err)
 	}
 	for len(b) > 0 {
 		nn := copy(w.buf[w.offset:], b)
@@ -360,14 +351,31 @@
 	if w.offset == 0 {
 		return nil
 	}
-	if w.onFlush != nil {
-		w.onFlush()
-	}
 	_, w.err = w.conn.Write(w.buf[:w.offset])
+	w.err = toIOError(w.err)
 	w.offset = 0
 	return w.err
 }
 
+type ioError struct {
+	error
+}
+
+func (i ioError) Unwrap() error {
+	return i.error
+}
+
+func isIOError(err error) bool {
+	return errors.As(err, &ioError{})
+}
+
+func toIOError(err error) error {
+	if err == nil {
+		return nil
+	}
+	return ioError{error: err}
+}
+
 type framer struct {
 	writer *bufWriter
 	fr     *http2.Framer
diff --git a/vendor/google.golang.org/grpc/internal/transport/logging.go b/vendor/google.golang.org/grpc/internal/transport/logging.go
new file mode 100644
index 0000000..42ed2b0
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/transport/logging.go
@@ -0,0 +1,40 @@
+/*
+ *
+ * Copyright 2023 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 transport
+
+import (
+	"fmt"
+
+	"google.golang.org/grpc/grpclog"
+	internalgrpclog "google.golang.org/grpc/internal/grpclog"
+)
+
+var logger = grpclog.Component("transport")
+
+func prefixLoggerForServerTransport(p *http2Server) *internalgrpclog.PrefixLogger {
+	return internalgrpclog.NewPrefixLogger(logger, fmt.Sprintf("[server-transport %p] ", p))
+}
+
+func prefixLoggerForServerHandlerTransport(p *serverHandlerTransport) *internalgrpclog.PrefixLogger {
+	return internalgrpclog.NewPrefixLogger(logger, fmt.Sprintf("[server-handler-transport %p] ", p))
+}
+
+func prefixLoggerForClientTransport(p *http2Client) *internalgrpclog.PrefixLogger {
+	return internalgrpclog.NewPrefixLogger(logger, fmt.Sprintf("[client-transport %p] ", p))
+}
diff --git a/vendor/google.golang.org/grpc/internal/transport/transport.go b/vendor/google.golang.org/grpc/internal/transport/transport.go
index d3bf65b..aa1c896 100644
--- a/vendor/google.golang.org/grpc/internal/transport/transport.go
+++ b/vendor/google.golang.org/grpc/internal/transport/transport.go
@@ -34,6 +34,7 @@
 
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/resolver"
@@ -42,6 +43,10 @@
 	"google.golang.org/grpc/tap"
 )
 
+// ErrNoHeaders is used as a signal that a trailers only response was received,
+// and is not a real error.
+var ErrNoHeaders = errors.New("stream has no headers")
+
 const logLevel = 2
 
 type bufferPool struct {
@@ -252,6 +257,9 @@
 	fc           *inFlow
 	wq           *writeQuota
 
+	// Holds compressor names passed in grpc-accept-encoding metadata from the
+	// client. This is empty for the client side stream.
+	clientAdvertisedCompressors string
 	// Callback to state application's intentions to read data. This
 	// is used to adjust flow control, if needed.
 	requestRead func(int)
@@ -340,8 +348,24 @@
 }
 
 // SetSendCompress sets the compression algorithm to the stream.
-func (s *Stream) SetSendCompress(str string) {
-	s.sendCompress = str
+func (s *Stream) SetSendCompress(name string) error {
+	if s.isHeaderSent() || s.getState() == streamDone {
+		return errors.New("transport: set send compressor called after headers sent or stream done")
+	}
+
+	s.sendCompress = name
+	return nil
+}
+
+// SendCompress returns the send compressor name.
+func (s *Stream) SendCompress() string {
+	return s.sendCompress
+}
+
+// ClientAdvertisedCompressors returns the compressor names advertised by the
+// client via grpc-accept-encoding header.
+func (s *Stream) ClientAdvertisedCompressors() string {
+	return s.clientAdvertisedCompressors
 }
 
 // Done returns a channel which is closed when it receives the final status
@@ -365,9 +389,15 @@
 		return s.header.Copy(), nil
 	}
 	s.waitOnHeader()
+
 	if !s.headerValid {
 		return nil, s.status.Err()
 	}
+
+	if s.noHeaders {
+		return nil, ErrNoHeaders
+	}
+
 	return s.header.Copy(), nil
 }
 
@@ -522,14 +552,14 @@
 	ConnectionTimeout     time.Duration
 	Credentials           credentials.TransportCredentials
 	InTapHandle           tap.ServerInHandle
-	StatsHandler          stats.Handler
+	StatsHandlers         []stats.Handler
 	KeepaliveParams       keepalive.ServerParameters
 	KeepalivePolicy       keepalive.EnforcementPolicy
 	InitialWindowSize     int32
 	InitialConnWindowSize int32
 	WriteBufferSize       int
 	ReadBufferSize        int
-	ChannelzParentID      int64
+	ChannelzParentID      *channelz.Identifier
 	MaxHeaderListSize     *uint32
 	HeaderTableSize       *uint32
 }
@@ -552,8 +582,8 @@
 	CredsBundle credentials.Bundle
 	// KeepaliveParams stores the keepalive parameters.
 	KeepaliveParams keepalive.ClientParameters
-	// StatsHandler stores the handler for stats.
-	StatsHandler stats.Handler
+	// StatsHandlers stores the handler for stats.
+	StatsHandlers []stats.Handler
 	// InitialWindowSize sets the initial window size for a stream.
 	InitialWindowSize int32
 	// InitialConnWindowSize sets the initial window size for a connection.
@@ -563,7 +593,7 @@
 	// ReadBufferSize sets the size of read buffer, which in turn determines how much data can be read at most for one read syscall.
 	ReadBufferSize int
 	// ChannelzParentID sets the addrConn id which initiate the creation of this client transport.
-	ChannelzParentID int64
+	ChannelzParentID *channelz.Identifier
 	// MaxHeaderListSize sets the max (uncompressed) size of header list that is prepared to be received.
 	MaxHeaderListSize *uint32
 	// UseProxy specifies if a proxy should be used.
@@ -572,8 +602,8 @@
 
 // NewClientTransport establishes the transport with the required ConnectOptions
 // and returns it to the caller.
-func NewClientTransport(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onPrefaceReceipt func(), onGoAway func(GoAwayReason), onClose func()) (ClientTransport, error) {
-	return newHTTP2Client(connectCtx, ctx, addr, opts, onPrefaceReceipt, onGoAway, onClose)
+func NewClientTransport(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onClose func(GoAwayReason)) (ClientTransport, error) {
+	return newHTTP2Client(connectCtx, ctx, addr, opts, onClose)
 }
 
 // Options provides additional hints and information for message
@@ -690,13 +720,13 @@
 	// Close tears down the transport. Once it is called, the transport
 	// should not be accessed any more. All the pending streams and their
 	// handlers will be terminated asynchronously.
-	Close()
+	Close(err error)
 
 	// RemoteAddr returns the remote network address.
 	RemoteAddr() net.Addr
 
 	// Drain notifies the client this ServerTransport stops accepting new RPCs.
-	Drain()
+	Drain(debugData string)
 
 	// IncrMsgSent increments the number of message sent through this transport.
 	IncrMsgSent()
@@ -741,6 +771,12 @@
 	return e.err
 }
 
+// Unwrap returns the original error of this connection error or nil when the
+// origin is nil.
+func (e ConnectionError) Unwrap() error {
+	return e.err
+}
+
 var (
 	// ErrConnClosing indicates that the transport is closing.
 	ErrConnClosing = connectionErrorf(true, nil, "transport is closing")