xds/ringhash: make reconnection logic work for a single subConn #5601
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,156 @@ | ||
| /* | ||
| * | ||
| * 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. | ||
| * | ||
| */ | ||
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| package ringhash_test | ||
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| import ( | ||
| "context" | ||
| "testing" | ||
| "time" | ||
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| "google.golang.org/grpc" | ||
| "google.golang.org/grpc/connectivity" | ||
| "google.golang.org/grpc/credentials/insecure" | ||
| "google.golang.org/grpc/internal/grpctest" | ||
| "google.golang.org/grpc/internal/testutils" | ||
| "google.golang.org/grpc/resolver" | ||
| "google.golang.org/grpc/resolver/manual" | ||
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| testgrpc "google.golang.org/grpc/test/grpc_testing" | ||
| testpb "google.golang.org/grpc/test/grpc_testing" | ||
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| _ "google.golang.org/grpc/xds/internal/balancer/ringhash" // Register the ring_hash_experimental LB policy. | ||
| ) | ||
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| type s struct { | ||
| grpctest.Tester | ||
| } | ||
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| func Test(t *testing.T) { | ||
| grpctest.RunSubTests(t, s{}) | ||
| } | ||
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| const ( | ||
| defaultTestTimeout = 10 * time.Second | ||
| defaultTestShortTimeout = 10 * time.Millisecond // For events expected to *not* happen. | ||
| ) | ||
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| type testService struct { | ||
| testpb.TestServiceServer | ||
| } | ||
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| func (*testService) EmptyCall(context.Context, *testpb.Empty) (*testpb.Empty, error) { | ||
| return &testpb.Empty{}, nil | ||
| } | ||
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| // TestRingHash_ReconnectToMoveOutOfTransientFailure tests the case where the | ||
| // ring contains a single subConn, and verifies that when the server goes down, | ||
| // the LB policy on the client automatically reconnects until the subChannel | ||
| // moves out of TRANSIENT_FAILURE. | ||
| func (s) TestRingHash_ReconnectToMoveOutOfTransientFailure(t *testing.T) { | ||
| // Create a restartable listener to simulate server being down. | ||
| l, err := testutils.LocalTCPListener() | ||
| if err != nil { | ||
| t.Fatalf("testutils.LocalTCPListener() failed: %v", err) | ||
| } | ||
| lis := testutils.NewRestartableListener(l) | ||
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| // Start a server backend exposing the test service. | ||
| server := grpc.NewServer() | ||
| defer server.Stop() | ||
| testgrpc.RegisterTestServiceServer(server, &testService{}) | ||
| go func() { | ||
| if err := server.Serve(lis); err != nil { | ||
| t.Errorf("Serve() failed: %v", err) | ||
| } | ||
| }() | ||
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| // Create a clientConn with a manual resolver (which is used to push the | ||
| // address of the test backend), and a default service config pointing to | ||
| // the use of the ring_hash_experimental LB policy. | ||
| const ringHashServiceConfig = `{"loadBalancingConfig": [{"ring_hash_experimental":{}}]}` | ||
| r := manual.NewBuilderWithScheme("whatever") | ||
| dopts := []grpc.DialOption{ | ||
| grpc.WithTransportCredentials(insecure.NewCredentials()), | ||
| grpc.WithResolvers(r), | ||
| grpc.WithDefaultServiceConfig(ringHashServiceConfig), | ||
| } | ||
| cc, err := grpc.Dial(r.Scheme()+":///test.server", dopts...) | ||
| if err != nil { | ||
| t.Fatalf("failed to dial local test server: %v", err) | ||
| } | ||
| defer cc.Close() | ||
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| // Push the address of the test backend through the manual resolver. | ||
| r.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: lis.Addr().String()}}}) | ||
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| ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout) | ||
| defer cancel() | ||
| client := testgrpc.NewTestServiceClient(cc) | ||
| if _, err := client.EmptyCall(ctx, &testpb.Empty{}); err != nil { | ||
| t.Fatalf("rpc EmptyCall() failed: %v", err) | ||
| } | ||
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| // Stopping the server listener will close the transport on the client, | ||
| // which will lead to the channel eventually moving to IDLE. The ring_hash | ||
| // LB policy is not expected to reconnect by itself at this point. | ||
| lis.Stop() | ||
| for ; ctx.Err() == nil; <-time.After(defaultTestShortTimeout) { | ||
| if cc.GetState() == connectivity.Idle { | ||
| break | ||
| } | ||
| } | ||
| if err := ctx.Err(); err != nil { | ||
| t.Fatalf("Timeout waiting for channel to reach %q after server shutdown: %v", connectivity.Idle, err) | ||
| } | ||
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| // Make an RPC to get the ring_hash LB policy to reconnect and thereby move | ||
| // to TRANSIENT_FAILURE upon connection failure. | ||
| client.EmptyCall(ctx, &testpb.Empty{}) | ||
| for ; ctx.Err() == nil; <-time.After(defaultTestShortTimeout) { | ||
| if cc.GetState() == connectivity.TransientFailure { | ||
| break | ||
| } | ||
| } | ||
| if err := ctx.Err(); err != nil { | ||
| t.Fatalf("Timeout waiting for channel to reach %q after server shutdown: %v", connectivity.TransientFailure, err) | ||
| } | ||
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| // An RPC at this point is expected to fail. | ||
| if _, err = client.EmptyCall(ctx, &testpb.Empty{}); err == nil { | ||
| t.Fatal("EmptyCall RPC succeeded when the channel is in TRANSIENT_FAILURE") | ||
| } | ||
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| // Restart the server listener. The ring_hash LB polcy is expected to | ||
| // attempt to reconnect on its own and come out of TRANSIENT_FAILURE, even | ||
| // without an RPC attempt. | ||
| lis.Restart() | ||
| for ; ctx.Err() == nil; <-time.After(defaultTestShortTimeout) { | ||
| if cc.GetState() == connectivity.Ready { | ||
| break | ||
| } | ||
| } | ||
| if err := ctx.Err(); err != nil { | ||
| t.Fatalf("Timeout waiting for channel to reach READT after server restart: %v", err) | ||
| } | ||
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| // An RPC at this point is expected to fail. | ||
| if _, err := client.EmptyCall(ctx, &testpb.Empty{}); err != nil { | ||
| t.Fatalf("rpc EmptyCall() failed: %v", err) | ||
| } | ||
| } | ||
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Code golf:
But why not use the connectivity state API? :
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Done.