grpc-go/test/clientconn_test.go

198 lines
6.9 KiB
Go

/*
*
* 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 test
import (
"context"
"fmt"
"strings"
"testing"
"time"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/connectivity"
"google.golang.org/grpc/credentials/insecure"
"google.golang.org/grpc/internal"
"google.golang.org/grpc/internal/channelz"
"google.golang.org/grpc/internal/grpcsync"
"google.golang.org/grpc/internal/stubserver"
"google.golang.org/grpc/internal/testutils"
testgrpc "google.golang.org/grpc/interop/grpc_testing"
testpb "google.golang.org/grpc/interop/grpc_testing"
"google.golang.org/grpc/resolver"
"google.golang.org/grpc/resolver/manual"
"google.golang.org/grpc/stats"
"google.golang.org/grpc/status"
)
// TestClientConnClose_WithPendingRPC tests the scenario where the channel has
// not yet received any update from the name resolver and hence RPCs are
// blocking. The test verifies that closing the ClientConn unblocks the RPC with
// the expected error code.
func (s) TestClientConnClose_WithPendingRPC(t *testing.T) {
r := manual.NewBuilderWithScheme("whatever")
cc, err := grpc.NewClient(r.Scheme()+":///test.server", grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithResolvers(r))
if err != nil {
t.Fatalf("grpc.NewClient() failed: %v", err)
}
client := testgrpc.NewTestServiceClient(cc)
ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
defer cancel()
doneErrCh := make(chan error, 1)
go func() {
// This RPC would block until the ClientConn is closed, because the
// resolver has not provided its first update yet.
_, err := client.EmptyCall(ctx, &testpb.Empty{})
if status.Code(err) != codes.Canceled || !strings.Contains(err.Error(), "client connection is closing") {
doneErrCh <- fmt.Errorf("EmptyCall() = %v, want %s", err, codes.Canceled)
}
doneErrCh <- nil
}()
// Make sure that there is one pending RPC on the ClientConn before attempting
// to close it. If we don't do this, cc.Close() can happen before the above
// goroutine gets to make the RPC.
for {
if err := ctx.Err(); err != nil {
t.Fatal(err)
}
tcs, _ := channelz.GetTopChannels(0, 0)
if len(tcs) != 1 {
t.Fatalf("there should only be one top channel, not %d", len(tcs))
}
started := tcs[0].ChannelMetrics.CallsStarted.Load()
completed := tcs[0].ChannelMetrics.CallsSucceeded.Load() + tcs[0].ChannelMetrics.CallsFailed.Load()
if (started - completed) == 1 {
break
}
time.Sleep(defaultTestShortTimeout)
}
cc.Close()
if err := <-doneErrCh; err != nil {
t.Fatal(err)
}
}
type testStatsHandler struct {
nameResolutionDelayed bool
}
// TagRPC is called when an RPC is initiated and allows adding metadata to the
// context. It checks if the RPC experienced a name resolution delay and
// updates the handler's state.
func (h *testStatsHandler) TagRPC(ctx context.Context, rpcInfo *stats.RPCTagInfo) context.Context {
h.nameResolutionDelayed = rpcInfo.NameResolutionDelay
return ctx
}
// This method is required to satisfy the stats.Handler interface.
func (h *testStatsHandler) HandleRPC(_ context.Context, _ stats.RPCStats) {}
// TagConn exists to satisfy stats.Handler.
func (h *testStatsHandler) TagConn(ctx context.Context, _ *stats.ConnTagInfo) context.Context {
return ctx
}
// HandleConn exists to satisfy stats.Handler.
func (h *testStatsHandler) HandleConn(_ context.Context, _ stats.ConnStats) {}
// TestClientConnRPC_WithoutNameResolutionDelay verify that if the resolution
// has already happened once before at the time of making RPC, the name
// resolution flag is not set indicating there was no delay in name resolution.
func (s) TestClientConnRPC_WithoutNameResolutionDelay(t *testing.T) {
statsHandler := &testStatsHandler{}
ss := &stubserver.StubServer{
EmptyCallF: func(context.Context, *testpb.Empty) (*testpb.Empty, error) {
return &testpb.Empty{}, nil
},
}
if err := ss.Start(nil, grpc.WithStatsHandler(statsHandler)); err != nil {
t.Fatalf("Failed to start StubServer: %v", err)
}
defer ss.Stop()
rb := manual.NewBuilderWithScheme("instant")
rb.InitialState(resolver.State{Addresses: []resolver.Address{{Addr: ss.Address}}})
cc := ss.CC
defer cc.Close()
cc.Connect()
ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
defer cancel()
testutils.AwaitState(ctx, t, cc, connectivity.Ready)
client := testgrpc.NewTestServiceClient(cc)
// Verify that the RPC succeeds.
if _, err := client.EmptyCall(ctx, &testpb.Empty{}); err != nil {
t.Fatalf("First RPC failed unexpectedly: %v", err)
}
// verifying that RPC was not blocked on resolver indicating there was no
// delay in name resolution.
if statsHandler.nameResolutionDelayed {
t.Fatalf("statsHandler.nameResolutionDelayed = %v; want false", statsHandler.nameResolutionDelayed)
}
}
// TestStatsHandlerDetectsResolutionDelay verifies that if this is the
// first time resolution is happening at the time of making RPC,
// nameResolutionDelayed flag is set indicating there was a delay in name
// resolution waiting for resolver to return addresses.
func (s) TestClientConnRPC_WithNameResolutionDelay(t *testing.T) {
resolutionWait := grpcsync.NewEvent()
prevHook := internal.NewStreamWaitingForResolver
internal.NewStreamWaitingForResolver = func() { resolutionWait.Fire() }
defer func() { internal.NewStreamWaitingForResolver = prevHook }()
ss := &stubserver.StubServer{
EmptyCallF: func(context.Context, *testpb.Empty) (*testpb.Empty, error) {
return &testpb.Empty{}, nil
},
}
if err := ss.Start(nil); err != nil {
t.Fatalf("Failed to start StubServer: %v", err)
}
defer ss.Stop()
statsHandler := &testStatsHandler{}
rb := manual.NewBuilderWithScheme("delayed")
cc, err := grpc.NewClient(rb.Scheme()+":///test.server",
grpc.WithTransportCredentials(insecure.NewCredentials()),
grpc.WithResolvers(rb),
grpc.WithStatsHandler(statsHandler),
)
if err != nil {
t.Fatalf("grpc.NewClient() failed: %v", err)
}
defer cc.Close()
go func() {
<-resolutionWait.Done()
rb.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: ss.Address}}})
}()
ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
defer cancel()
client := testgrpc.NewTestServiceClient(cc)
if _, err := client.EmptyCall(ctx, &testpb.Empty{}); err != nil {
t.Fatalf("EmptyCall RPC failed: %v", err)
}
if !statsHandler.nameResolutionDelayed {
t.Fatalf("statsHandler.nameResolutionDelayed = %v; want true", statsHandler.nameResolutionDelayed)
}
}