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GrpclbLoadBalancerTest.java
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GrpclbLoadBalancerTest.java
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/*
* Copyright 2016 The 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 io.grpc.grpclb;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.truth.Truth.assertThat;
import static io.grpc.ConnectivityState.CONNECTING;
import static io.grpc.ConnectivityState.IDLE;
import static io.grpc.ConnectivityState.READY;
import static io.grpc.ConnectivityState.SHUTDOWN;
import static io.grpc.ConnectivityState.TRANSIENT_FAILURE;
import static io.grpc.grpclb.GrpclbState.BUFFER_ENTRY;
import static io.grpc.grpclb.GrpclbState.DROP_PICK_RESULT;
import static io.grpc.grpclb.GrpclbState.NO_USE_AUTHORITY_SUFFIX;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertSame;
import static org.junit.Assert.assertTrue;
import static org.mockito.AdditionalAnswers.delegatesTo;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyString;
import static org.mockito.ArgumentMatchers.eq;
import static org.mockito.ArgumentMatchers.same;
import static org.mockito.Mockito.atLeast;
import static org.mockito.Mockito.doAnswer;
import static org.mockito.Mockito.inOrder;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyNoMoreInteractions;
import static org.mockito.Mockito.when;
import com.google.common.collect.Iterables;
import com.google.protobuf.ByteString;
import com.google.protobuf.util.Durations;
import com.google.protobuf.util.Timestamps;
import io.grpc.Attributes;
import io.grpc.ChannelLogger;
import io.grpc.ClientStreamTracer;
import io.grpc.ConnectivityState;
import io.grpc.ConnectivityStateInfo;
import io.grpc.Context;
import io.grpc.Context.CancellableContext;
import io.grpc.EquivalentAddressGroup;
import io.grpc.LoadBalancer.CreateSubchannelArgs;
import io.grpc.LoadBalancer.Helper;
import io.grpc.LoadBalancer.PickResult;
import io.grpc.LoadBalancer.PickSubchannelArgs;
import io.grpc.LoadBalancer.ResolvedAddresses;
import io.grpc.LoadBalancer.Subchannel;
import io.grpc.LoadBalancer.SubchannelPicker;
import io.grpc.LoadBalancer.SubchannelStateListener;
import io.grpc.ManagedChannel;
import io.grpc.Metadata;
import io.grpc.Status;
import io.grpc.Status.Code;
import io.grpc.SynchronizationContext;
import io.grpc.grpclb.GrpclbState.BackendEntry;
import io.grpc.grpclb.GrpclbState.DropEntry;
import io.grpc.grpclb.GrpclbState.ErrorEntry;
import io.grpc.grpclb.GrpclbState.IdleSubchannelEntry;
import io.grpc.grpclb.GrpclbState.Mode;
import io.grpc.grpclb.GrpclbState.RoundRobinPicker;
import io.grpc.inprocess.InProcessChannelBuilder;
import io.grpc.inprocess.InProcessServerBuilder;
import io.grpc.internal.BackoffPolicy;
import io.grpc.internal.FakeClock;
import io.grpc.lb.v1.ClientStats;
import io.grpc.lb.v1.ClientStatsPerToken;
import io.grpc.lb.v1.FallbackResponse;
import io.grpc.lb.v1.InitialLoadBalanceRequest;
import io.grpc.lb.v1.InitialLoadBalanceResponse;
import io.grpc.lb.v1.LoadBalanceRequest;
import io.grpc.lb.v1.LoadBalanceResponse;
import io.grpc.lb.v1.LoadBalancerGrpc;
import io.grpc.lb.v1.Server;
import io.grpc.lb.v1.ServerList;
import io.grpc.stub.StreamObserver;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.text.MessageFormat;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
import org.mockito.AdditionalAnswers;
import org.mockito.ArgumentCaptor;
import org.mockito.ArgumentMatchers;
import org.mockito.Captor;
import org.mockito.InOrder;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;
/** Unit tests for {@link GrpclbLoadBalancer}. */
@RunWith(JUnit4.class)
public class GrpclbLoadBalancerTest {
private static final String SERVICE_AUTHORITY = "api.google.com";
// The tasks are wrapped by SynchronizationContext, so we can't compare the types
// directly.
private static final FakeClock.TaskFilter LOAD_REPORTING_TASK_FILTER =
new FakeClock.TaskFilter() {
@Override
public boolean shouldAccept(Runnable command) {
return command.toString().contains(GrpclbState.LoadReportingTask.class.getSimpleName());
}
};
private static final FakeClock.TaskFilter FALLBACK_MODE_TASK_FILTER =
new FakeClock.TaskFilter() {
@Override
public boolean shouldAccept(Runnable command) {
return command.toString().contains(GrpclbState.FallbackModeTask.class.getSimpleName());
}
};
private static final FakeClock.TaskFilter LB_RPC_RETRY_TASK_FILTER =
new FakeClock.TaskFilter() {
@Override
public boolean shouldAccept(Runnable command) {
return command.toString().contains(GrpclbState.LbRpcRetryTask.class.getSimpleName());
}
};
private static final Attributes LB_BACKEND_ATTRS =
Attributes.newBuilder().set(GrpclbConstants.ATTR_LB_PROVIDED_BACKEND, true).build();
private final Helper helper = mock(Helper.class, delegatesTo(new FakeHelper()));
private final SubchannelPool subchannelPool =
mock(
SubchannelPool.class,
delegatesTo(new CachedSubchannelPool(helper)));
private final ArrayList<String> logs = new ArrayList<>();
private final ChannelLogger channelLogger = new ChannelLogger() {
@Override
public void log(ChannelLogLevel level, String msg) {
logs.add(level + ": " + msg);
}
@Override
public void log(ChannelLogLevel level, String template, Object... args) {
log(level, MessageFormat.format(template, args));
}
};
private SubchannelPicker currentPicker;
private LoadBalancerGrpc.LoadBalancerImplBase mockLbService;
@Captor
private ArgumentCaptor<StreamObserver<LoadBalanceResponse>> lbResponseObserverCaptor;
private final FakeClock fakeClock = new FakeClock();
private final ArrayDeque<StreamObserver<LoadBalanceRequest>> lbRequestObservers =
new ArrayDeque<>();
private final ArrayDeque<Subchannel> mockSubchannels = new ArrayDeque<>();
private final ArrayDeque<ManagedChannel> fakeOobChannels = new ArrayDeque<>();
private final ArrayList<Subchannel> unpooledSubchannelTracker = new ArrayList<>();
private final ArrayList<ManagedChannel> oobChannelTracker = new ArrayList<>();
private final SynchronizationContext syncContext = new SynchronizationContext(
new Thread.UncaughtExceptionHandler() {
@Override
public void uncaughtException(Thread t, Throwable e) {
throw new AssertionError(e);
}
});
private static final ClientStreamTracer.StreamInfo STREAM_INFO =
ClientStreamTracer.StreamInfo.newBuilder().build();
private io.grpc.Server fakeLbServer;
@Captor
private ArgumentCaptor<SubchannelPicker> pickerCaptor;
@Mock
private BackoffPolicy.Provider backoffPolicyProvider;
@Mock
private BackoffPolicy backoffPolicy1;
@Mock
private BackoffPolicy backoffPolicy2;
private GrpclbLoadBalancer balancer;
private final ArgumentCaptor<CreateSubchannelArgs> createSubchannelArgsCaptor =
ArgumentCaptor.forClass(CreateSubchannelArgs.class);
@Before
public void setUp() throws Exception {
MockitoAnnotations.initMocks(this);
mockLbService = mock(LoadBalancerGrpc.LoadBalancerImplBase.class, delegatesTo(
new LoadBalancerGrpc.LoadBalancerImplBase() {
@Override
@SuppressWarnings("unchecked")
public StreamObserver<LoadBalanceRequest> balanceLoad(
final StreamObserver<LoadBalanceResponse> responseObserver) {
StreamObserver<LoadBalanceRequest> requestObserver =
mock(StreamObserver.class);
Answer<Void> closeRpc = new Answer<Void>() {
@Override
public Void answer(InvocationOnMock invocation) {
responseObserver.onCompleted();
return null;
}
};
doAnswer(closeRpc).when(requestObserver).onCompleted();
lbRequestObservers.add(requestObserver);
return requestObserver;
}
}));
fakeLbServer = InProcessServerBuilder.forName("fakeLb")
.directExecutor().addService(mockLbService).build().start();
when(backoffPolicy1.nextBackoffNanos()).thenReturn(10L, 100L);
when(backoffPolicy2.nextBackoffNanos()).thenReturn(10L, 100L);
when(backoffPolicyProvider.get()).thenReturn(backoffPolicy1, backoffPolicy2);
balancer = new GrpclbLoadBalancer(
helper,
Context.ROOT,
subchannelPool,
fakeClock.getTimeProvider(),
fakeClock.getStopwatchSupplier().get(),
backoffPolicyProvider);
}
@After
public void tearDown() {
try {
if (balancer != null) {
syncContext.execute(new Runnable() {
@Override
public void run() {
balancer.shutdown();
}
});
}
for (ManagedChannel channel : oobChannelTracker) {
assertTrue(channel + " is shutdown", channel.isShutdown());
// balancer should have closed the LB stream, terminating the OOB channel.
assertTrue(channel + " is terminated", channel.isTerminated());
}
for (Subchannel subchannel : unpooledSubchannelTracker) {
verify(subchannel).shutdown();
}
// No timer should linger after shutdown
assertThat(fakeClock.getPendingTasks()).isEmpty();
} finally {
if (fakeLbServer != null) {
fakeLbServer.shutdownNow();
}
}
}
@Test
public void roundRobinPickerNoDrop() {
GrpclbClientLoadRecorder loadRecorder =
new GrpclbClientLoadRecorder(fakeClock.getTimeProvider());
Subchannel subchannel = mock(Subchannel.class);
BackendEntry b1 = new BackendEntry(subchannel, loadRecorder, "LBTOKEN0001");
BackendEntry b2 = new BackendEntry(subchannel, loadRecorder, "LBTOKEN0002");
List<BackendEntry> pickList = Arrays.asList(b1, b2);
RoundRobinPicker picker = new RoundRobinPicker(Collections.<DropEntry>emptyList(), pickList);
PickSubchannelArgs args1 = mock(PickSubchannelArgs.class);
Metadata headers1 = new Metadata();
// The existing token on the headers will be replaced
headers1.put(GrpclbConstants.TOKEN_METADATA_KEY, "LBTOKEN__OLD");
when(args1.getHeaders()).thenReturn(headers1);
assertSame(b1.result, picker.pickSubchannel(args1));
verify(args1).getHeaders();
assertThat(headers1.getAll(GrpclbConstants.TOKEN_METADATA_KEY)).containsExactly("LBTOKEN0001");
PickSubchannelArgs args2 = mock(PickSubchannelArgs.class);
Metadata headers2 = new Metadata();
when(args2.getHeaders()).thenReturn(headers2);
assertSame(b2.result, picker.pickSubchannel(args2));
verify(args2).getHeaders();
assertThat(headers2.getAll(GrpclbConstants.TOKEN_METADATA_KEY)).containsExactly("LBTOKEN0002");
PickSubchannelArgs args3 = mock(PickSubchannelArgs.class);
Metadata headers3 = new Metadata();
when(args3.getHeaders()).thenReturn(headers3);
assertSame(b1.result, picker.pickSubchannel(args3));
verify(args3).getHeaders();
assertThat(headers3.getAll(GrpclbConstants.TOKEN_METADATA_KEY)).containsExactly("LBTOKEN0001");
verify(subchannel, never()).getAttributes();
}
@Test
public void roundRobinPickerWithDrop() {
assertTrue(DROP_PICK_RESULT.isDrop());
GrpclbClientLoadRecorder loadRecorder =
new GrpclbClientLoadRecorder(fakeClock.getTimeProvider());
Subchannel subchannel = mock(Subchannel.class);
// 1 out of 2 requests are to be dropped
DropEntry d = new DropEntry(loadRecorder, "LBTOKEN0003");
List<DropEntry> dropList = Arrays.asList(null, d);
BackendEntry b1 = new BackendEntry(subchannel, loadRecorder, "LBTOKEN0001");
BackendEntry b2 = new BackendEntry(subchannel, loadRecorder, "LBTOKEN0002");
List<BackendEntry> pickList = Arrays.asList(b1, b2);
RoundRobinPicker picker = new RoundRobinPicker(dropList, pickList);
// dropList[0], pickList[0]
PickSubchannelArgs args1 = mock(PickSubchannelArgs.class);
Metadata headers1 = new Metadata();
headers1.put(GrpclbConstants.TOKEN_METADATA_KEY, "LBTOKEN__OLD");
when(args1.getHeaders()).thenReturn(headers1);
assertSame(b1.result, picker.pickSubchannel(args1));
verify(args1).getHeaders();
assertThat(headers1.getAll(GrpclbConstants.TOKEN_METADATA_KEY)).containsExactly("LBTOKEN0001");
// dropList[1]: drop
PickSubchannelArgs args2 = mock(PickSubchannelArgs.class);
Metadata headers2 = new Metadata();
when(args2.getHeaders()).thenReturn(headers2);
assertSame(DROP_PICK_RESULT, picker.pickSubchannel(args2));
verify(args2, never()).getHeaders();
// dropList[0], pickList[1]
PickSubchannelArgs args3 = mock(PickSubchannelArgs.class);
Metadata headers3 = new Metadata();
when(args3.getHeaders()).thenReturn(headers3);
assertSame(b2.result, picker.pickSubchannel(args3));
verify(args3).getHeaders();
assertThat(headers3.getAll(GrpclbConstants.TOKEN_METADATA_KEY)).containsExactly("LBTOKEN0002");
// dropList[1]: drop
PickSubchannelArgs args4 = mock(PickSubchannelArgs.class);
Metadata headers4 = new Metadata();
when(args4.getHeaders()).thenReturn(headers4);
assertSame(DROP_PICK_RESULT, picker.pickSubchannel(args4));
verify(args4, never()).getHeaders();
// dropList[0], pickList[0]
PickSubchannelArgs args5 = mock(PickSubchannelArgs.class);
Metadata headers5 = new Metadata();
when(args5.getHeaders()).thenReturn(headers5);
assertSame(b1.result, picker.pickSubchannel(args5));
verify(args5).getHeaders();
assertThat(headers5.getAll(GrpclbConstants.TOKEN_METADATA_KEY)).containsExactly("LBTOKEN0001");
verify(subchannel, never()).getAttributes();
}
@Test
public void roundRobinPickerWithIdleEntry_noDrop() {
Subchannel subchannel = mock(Subchannel.class);
IdleSubchannelEntry entry = new IdleSubchannelEntry(subchannel, syncContext);
RoundRobinPicker picker =
new RoundRobinPicker(Collections.<DropEntry>emptyList(), Collections.singletonList(entry));
PickSubchannelArgs args = mock(PickSubchannelArgs.class);
verify(subchannel, never()).requestConnection();
assertThat(picker.pickSubchannel(args)).isSameInstanceAs(PickResult.withNoResult());
verify(subchannel).requestConnection();
assertThat(picker.pickSubchannel(args)).isSameInstanceAs(PickResult.withNoResult());
// Only the first pick triggers requestConnection()
verify(subchannel).requestConnection();
}
@Test
public void roundRobinPickerWithIdleEntry_andDrop() {
GrpclbClientLoadRecorder loadRecorder =
new GrpclbClientLoadRecorder(fakeClock.getTimeProvider());
// 1 out of 2 requests are to be dropped
DropEntry d = new DropEntry(loadRecorder, "LBTOKEN0003");
List<DropEntry> dropList = Arrays.asList(null, d);
Subchannel subchannel = mock(Subchannel.class);
IdleSubchannelEntry entry = new IdleSubchannelEntry(subchannel, syncContext);
RoundRobinPicker picker = new RoundRobinPicker(dropList, Collections.singletonList(entry));
PickSubchannelArgs args = mock(PickSubchannelArgs.class);
verify(subchannel, never()).requestConnection();
assertThat(picker.pickSubchannel(args)).isSameInstanceAs(PickResult.withNoResult());
verify(subchannel).requestConnection();
assertThat(picker.pickSubchannel(args)).isSameInstanceAs(DROP_PICK_RESULT);
verify(subchannel).requestConnection();
assertThat(picker.pickSubchannel(args)).isSameInstanceAs(PickResult.withNoResult());
// Only the first pick triggers requestConnection()
verify(subchannel).requestConnection();
}
@Test
public void loadReporting() {
Metadata headers = new Metadata();
PickSubchannelArgs args = mock(PickSubchannelArgs.class);
when(args.getHeaders()).thenReturn(headers);
long loadReportIntervalMillis = 1983;
List<EquivalentAddressGroup> grpclbBalancerList = createResolvedBalancerAddresses(1);
deliverResolvedAddresses(Collections.<EquivalentAddressGroup>emptyList(), grpclbBalancerList);
// Fallback timer is started as soon as address is resolved.
assertEquals(1, fakeClock.numPendingTasks(FALLBACK_MODE_TASK_FILTER));
assertEquals(1, fakeOobChannels.size());
verify(mockLbService).balanceLoad(lbResponseObserverCaptor.capture());
StreamObserver<LoadBalanceResponse> lbResponseObserver = lbResponseObserverCaptor.getValue();
assertEquals(1, lbRequestObservers.size());
StreamObserver<LoadBalanceRequest> lbRequestObserver = lbRequestObservers.poll();
InOrder inOrder = inOrder(lbRequestObserver);
InOrder helperInOrder = inOrder(helper, subchannelPool);
inOrder.verify(lbRequestObserver).onNext(
eq(LoadBalanceRequest.newBuilder().setInitialRequest(
InitialLoadBalanceRequest.newBuilder().setName(SERVICE_AUTHORITY).build())
.build()));
// Simulate receiving LB response
assertEquals(0, fakeClock.numPendingTasks(LOAD_REPORTING_TASK_FILTER));
lbResponseObserver.onNext(buildInitialResponse(loadReportIntervalMillis));
// Load reporting task is scheduled
assertEquals(1, fakeClock.numPendingTasks(LOAD_REPORTING_TASK_FILTER));
assertEquals(0, fakeClock.runDueTasks());
List<ServerEntry> backends = Arrays.asList(
new ServerEntry("127.0.0.1", 2000, "token0001"),
new ServerEntry("token0001"), // drop
new ServerEntry("127.0.0.1", 2010, "token0002"),
new ServerEntry("token0003")); // drop
lbResponseObserver.onNext(buildLbResponse(backends));
assertEquals(2, mockSubchannels.size());
Subchannel subchannel1 = mockSubchannels.poll();
Subchannel subchannel2 = mockSubchannels.poll();
deliverSubchannelState(subchannel1, ConnectivityStateInfo.forNonError(CONNECTING));
deliverSubchannelState(subchannel2, ConnectivityStateInfo.forNonError(CONNECTING));
deliverSubchannelState(subchannel1, ConnectivityStateInfo.forNonError(READY));
deliverSubchannelState(subchannel2, ConnectivityStateInfo.forNonError(READY));
helperInOrder.verify(helper, atLeast(1))
.updateBalancingState(eq(READY), pickerCaptor.capture());
RoundRobinPicker picker = (RoundRobinPicker) pickerCaptor.getValue();
assertThat(picker.dropList).containsExactly(
null,
new DropEntry(getLoadRecorder(), "token0001"),
null,
new DropEntry(getLoadRecorder(), "token0003")).inOrder();
assertThat(picker.pickList).containsExactly(
new BackendEntry(subchannel1, getLoadRecorder(), "token0001"),
new BackendEntry(subchannel2, getLoadRecorder(), "token0002")).inOrder();
// Report, no data
assertNextReport(
inOrder, lbRequestObserver, loadReportIntervalMillis,
ClientStats.newBuilder().build());
PickResult pick1 = picker.pickSubchannel(args);
assertSame(subchannel1, pick1.getSubchannel());
assertSame(getLoadRecorder(), pick1.getStreamTracerFactory());
// Merely the pick will not be recorded as upstart.
assertNextReport(
inOrder, lbRequestObserver, loadReportIntervalMillis,
ClientStats.newBuilder().build());
ClientStreamTracer tracer1 =
pick1.getStreamTracerFactory().newClientStreamTracer(STREAM_INFO, new Metadata());
PickResult pick2 = picker.pickSubchannel(args);
assertNull(pick2.getSubchannel());
assertSame(DROP_PICK_RESULT, pick2);
// Report includes upstart of pick1 and the drop of pick2
assertNextReport(
inOrder, lbRequestObserver, loadReportIntervalMillis,
ClientStats.newBuilder()
.setNumCallsStarted(2)
.setNumCallsFinished(1) // pick2
.addCallsFinishedWithDrop(
ClientStatsPerToken.newBuilder()
.setLoadBalanceToken("token0001")
.setNumCalls(1) // pick2
.build())
.build());
PickResult pick3 = picker.pickSubchannel(args);
assertSame(subchannel2, pick3.getSubchannel());
assertSame(getLoadRecorder(), pick3.getStreamTracerFactory());
ClientStreamTracer tracer3 =
pick3.getStreamTracerFactory().newClientStreamTracer(STREAM_INFO, new Metadata());
// pick3 has sent out headers
tracer3.outboundHeaders();
// 3rd report includes pick3's upstart
assertNextReport(
inOrder, lbRequestObserver, loadReportIntervalMillis,
ClientStats.newBuilder()
.setNumCallsStarted(1)
.build());
PickResult pick4 = picker.pickSubchannel(args);
assertNull(pick4.getSubchannel());
assertSame(DROP_PICK_RESULT, pick4);
// pick1 ended without sending anything
tracer1.streamClosed(Status.CANCELLED);
// 4th report includes end of pick1 and drop of pick4
assertNextReport(
inOrder, lbRequestObserver, loadReportIntervalMillis,
ClientStats.newBuilder()
.setNumCallsStarted(1) // pick4
.setNumCallsFinished(2)
.setNumCallsFinishedWithClientFailedToSend(1) // pick1
.addCallsFinishedWithDrop(
ClientStatsPerToken.newBuilder()
.setLoadBalanceToken("token0003")
.setNumCalls(1) // pick4
.build())
.build());
PickResult pick5 = picker.pickSubchannel(args);
assertSame(subchannel1, pick1.getSubchannel());
assertSame(getLoadRecorder(), pick5.getStreamTracerFactory());
ClientStreamTracer tracer5 =
pick5.getStreamTracerFactory().newClientStreamTracer(STREAM_INFO, new Metadata());
// pick3 ended without receiving response headers
tracer3.streamClosed(Status.DEADLINE_EXCEEDED);
// pick5 sent and received headers
tracer5.outboundHeaders();
tracer5.inboundHeaders();
// 5th report includes pick3's end and pick5's upstart
assertNextReport(
inOrder, lbRequestObserver, loadReportIntervalMillis,
ClientStats.newBuilder()
.setNumCallsStarted(1) // pick5
.setNumCallsFinished(1) // pick3
.build());
// pick5 ends
tracer5.streamClosed(Status.OK);
// 6th report includes pick5's end
assertNextReport(
inOrder, lbRequestObserver, loadReportIntervalMillis,
ClientStats.newBuilder()
.setNumCallsFinished(1)
.setNumCallsFinishedKnownReceived(1)
.build());
assertEquals(1, fakeClock.numPendingTasks());
// Balancer closes the stream, scheduled reporting task cancelled
lbResponseObserver.onError(Status.UNAVAILABLE.asException());
assertEquals(0, fakeClock.numPendingTasks());
// New stream created
verify(mockLbService, times(2)).balanceLoad(lbResponseObserverCaptor.capture());
lbResponseObserver = lbResponseObserverCaptor.getValue();
assertEquals(1, lbRequestObservers.size());
lbRequestObserver = lbRequestObservers.poll();
inOrder = inOrder(lbRequestObserver);
inOrder.verify(lbRequestObserver).onNext(
eq(LoadBalanceRequest.newBuilder().setInitialRequest(
InitialLoadBalanceRequest.newBuilder().setName(SERVICE_AUTHORITY).build())
.build()));
// Load reporting is also requested
lbResponseObserver.onNext(buildInitialResponse(loadReportIntervalMillis));
// No picker created because balancer is still using the results from the last stream
helperInOrder.verify(helper, never())
.updateBalancingState(any(ConnectivityState.class), any(SubchannelPicker.class));
// Make a new pick on that picker. It will not show up on the report of the new stream, because
// that picker is associated with the previous stream.
PickResult pick6 = picker.pickSubchannel(args);
assertNull(pick6.getSubchannel());
assertSame(DROP_PICK_RESULT, pick6);
assertNextReport(
inOrder, lbRequestObserver, loadReportIntervalMillis,
ClientStats.newBuilder().build());
// New stream got the list update
lbResponseObserver.onNext(buildLbResponse(backends));
// Same backends, thus no new subchannels
helperInOrder.verify(subchannelPool, never()).takeOrCreateSubchannel(
any(EquivalentAddressGroup.class), any(Attributes.class));
// But the new RoundRobinEntries have a new loadRecorder, thus considered different from
// the previous list, thus a new picker is created
helperInOrder.verify(helper).updateBalancingState(eq(READY), pickerCaptor.capture());
picker = (RoundRobinPicker) pickerCaptor.getValue();
PickResult pick1p = picker.pickSubchannel(args);
assertSame(subchannel1, pick1p.getSubchannel());
assertSame(getLoadRecorder(), pick1p.getStreamTracerFactory());
pick1p.getStreamTracerFactory().newClientStreamTracer(STREAM_INFO, new Metadata());
// The pick from the new stream will be included in the report
assertNextReport(
inOrder, lbRequestObserver, loadReportIntervalMillis,
ClientStats.newBuilder()
.setNumCallsStarted(1)
.build());
verify(args, atLeast(0)).getHeaders();
verifyNoMoreInteractions(args);
}
@Test
public void abundantInitialResponse() {
Metadata headers = new Metadata();
PickSubchannelArgs args = mock(PickSubchannelArgs.class);
when(args.getHeaders()).thenReturn(headers);
List<EquivalentAddressGroup> grpclbBalancerList = createResolvedBalancerAddresses(1);
deliverResolvedAddresses(Collections.<EquivalentAddressGroup>emptyList(), grpclbBalancerList);
assertEquals(1, fakeOobChannels.size());
verify(mockLbService).balanceLoad(lbResponseObserverCaptor.capture());
StreamObserver<LoadBalanceResponse> lbResponseObserver = lbResponseObserverCaptor.getValue();
// Simulate LB initial response
assertEquals(0, fakeClock.numPendingTasks(LOAD_REPORTING_TASK_FILTER));
lbResponseObserver.onNext(buildInitialResponse(1983));
// Load reporting task is scheduled
assertEquals(1, fakeClock.numPendingTasks(LOAD_REPORTING_TASK_FILTER));
FakeClock.ScheduledTask scheduledTask =
Iterables.getOnlyElement(fakeClock.getPendingTasks(LOAD_REPORTING_TASK_FILTER));
assertEquals(1983, scheduledTask.getDelay(TimeUnit.MILLISECONDS));
logs.clear();
// Simulate an abundant LB initial response, with a different report interval
lbResponseObserver.onNext(buildInitialResponse(9097));
// This incident is logged
assertThat(logs).containsExactly(
"DEBUG: [grpclb-<api.google.com>] Got an LB response: " + buildInitialResponse(9097),
"WARNING: [grpclb-<api.google.com>] "
+ "Ignoring unexpected response type: INITIAL_RESPONSE")
.inOrder();
// It doesn't affect load-reporting at all
assertThat(fakeClock.getPendingTasks(LOAD_REPORTING_TASK_FILTER))
.containsExactly(scheduledTask);
assertEquals(1983, scheduledTask.getDelay(TimeUnit.MILLISECONDS));
}
@SuppressWarnings("unchecked")
@Test
public void raceBetweenHandleAddressesAndLbStreamClosure() {
InOrder inOrder = inOrder(mockLbService, backoffPolicyProvider, backoffPolicy1);
deliverResolvedAddresses(Collections.<EquivalentAddressGroup>emptyList(),
createResolvedBalancerAddresses(1));
assertEquals(1, fakeOobChannels.size());
inOrder.verify(mockLbService).balanceLoad(lbResponseObserverCaptor.capture());
StreamObserver<LoadBalanceResponse> lbResponseObserver = lbResponseObserverCaptor.getValue();
assertEquals(1, lbRequestObservers.size());
StreamObserver<LoadBalanceRequest> lbRequestObserver = lbRequestObservers.poll();
verify(lbRequestObserver).onNext(
eq(LoadBalanceRequest.newBuilder().setInitialRequest(
InitialLoadBalanceRequest.newBuilder().setName(SERVICE_AUTHORITY).build())
.build()));
// Close lbStream
lbResponseObserver.onCompleted();
inOrder.verify(backoffPolicyProvider).get();
inOrder.verify(backoffPolicy1).nextBackoffNanos();
// Retry task scheduled
assertEquals(1, fakeClock.numPendingTasks(LB_RPC_RETRY_TASK_FILTER));
FakeClock.ScheduledTask retryTask =
Iterables.getOnlyElement(fakeClock.getPendingTasks(LB_RPC_RETRY_TASK_FILTER));
assertEquals(10L, retryTask.getDelay(TimeUnit.NANOSECONDS));
// Receive the same Lb address again
deliverResolvedAddresses(Collections.<EquivalentAddressGroup>emptyList(),
createResolvedBalancerAddresses(1));
// Retry task cancelled
assertEquals(0, fakeClock.numPendingTasks(LB_RPC_RETRY_TASK_FILTER));
// Reuse the existing OOB channel
assertEquals(1, fakeOobChannels.size());
// Start a new LoadBalance RPC
inOrder.verify(mockLbService).balanceLoad(any(StreamObserver.class));
assertEquals(1, lbRequestObservers.size());
lbRequestObserver = lbRequestObservers.poll();
verify(lbRequestObserver).onNext(
eq(LoadBalanceRequest.newBuilder().setInitialRequest(
InitialLoadBalanceRequest.newBuilder().setName(SERVICE_AUTHORITY).build())
.build()));
// Simulate a race condition where the task has just started when it's cancelled
retryTask.command.run();
inOrder.verifyNoMoreInteractions();
}
@Test
public void raceBetweenLoadReportingAndLbStreamClosure() {
Metadata headers = new Metadata();
PickSubchannelArgs args = mock(PickSubchannelArgs.class);
when(args.getHeaders()).thenReturn(headers);
List<EquivalentAddressGroup> grpclbBalancerList = createResolvedBalancerAddresses(1);
deliverResolvedAddresses(Collections.<EquivalentAddressGroup>emptyList(), grpclbBalancerList);
assertEquals(1, fakeOobChannels.size());
verify(mockLbService).balanceLoad(lbResponseObserverCaptor.capture());
StreamObserver<LoadBalanceResponse> lbResponseObserver = lbResponseObserverCaptor.getValue();
assertEquals(1, lbRequestObservers.size());
StreamObserver<LoadBalanceRequest> lbRequestObserver = lbRequestObservers.poll();
InOrder inOrder = inOrder(lbRequestObserver);
inOrder.verify(lbRequestObserver).onNext(
eq(LoadBalanceRequest.newBuilder().setInitialRequest(
InitialLoadBalanceRequest.newBuilder().setName(SERVICE_AUTHORITY).build())
.build()));
// Simulate receiving LB response
assertEquals(0, fakeClock.numPendingTasks(LOAD_REPORTING_TASK_FILTER));
lbResponseObserver.onNext(buildInitialResponse(1983));
// Load reporting task is scheduled
assertEquals(1, fakeClock.numPendingTasks(LOAD_REPORTING_TASK_FILTER));
FakeClock.ScheduledTask scheduledTask =
Iterables.getOnlyElement(fakeClock.getPendingTasks(LOAD_REPORTING_TASK_FILTER));
assertEquals(1983, scheduledTask.getDelay(TimeUnit.MILLISECONDS));
// Close lbStream
lbResponseObserver.onCompleted();
// Reporting task cancelled
assertEquals(0, fakeClock.numPendingTasks(LOAD_REPORTING_TASK_FILTER));
// Simulate a race condition where the task has just started when its cancelled
scheduledTask.command.run();
// No report sent. No new task scheduled
inOrder.verify(lbRequestObserver, never()).onNext(any(LoadBalanceRequest.class));
assertEquals(0, fakeClock.numPendingTasks(LOAD_REPORTING_TASK_FILTER));
}
private void assertNextReport(
InOrder inOrder, StreamObserver<LoadBalanceRequest> lbRequestObserver,
long loadReportIntervalMillis, ClientStats expectedReport) {
assertEquals(0, fakeClock.forwardTime(loadReportIntervalMillis - 1, TimeUnit.MILLISECONDS));
inOrder.verifyNoMoreInteractions();
assertEquals(1, fakeClock.forwardTime(1, TimeUnit.MILLISECONDS));
assertEquals(1, fakeClock.numPendingTasks());
inOrder.verify(lbRequestObserver).onNext(
eq(LoadBalanceRequest.newBuilder()
.setClientStats(
ClientStats.newBuilder(expectedReport)
.setTimestamp(Timestamps.fromNanos(fakeClock.getTicker().read()))
.build())
.build()));
}
@Test
public void receiveNoBackendAndBalancerAddress() {
deliverResolvedAddresses(
Collections.<EquivalentAddressGroup>emptyList(),
Collections.<EquivalentAddressGroup>emptyList());
verify(helper).updateBalancingState(eq(TRANSIENT_FAILURE), pickerCaptor.capture());
RoundRobinPicker picker = (RoundRobinPicker) pickerCaptor.getValue();
assertThat(picker.dropList).isEmpty();
Status error = Iterables.getOnlyElement(picker.pickList).picked(new Metadata()).getStatus();
assertThat(error.getCode()).isEqualTo(Code.UNAVAILABLE);
assertThat(error.getDescription()).isEqualTo("No backend or balancer addresses found");
}
@Test
public void nameResolutionFailsThenRecover() {
Status error = Status.NOT_FOUND.withDescription("www.google.com not found");
deliverNameResolutionError(error);
verify(helper).updateBalancingState(eq(TRANSIENT_FAILURE), pickerCaptor.capture());
assertThat(logs).containsExactly(
"INFO: [grpclb-<api.google.com>] Created",
"DEBUG: [grpclb-<api.google.com>] Error: " + error,
"INFO: [grpclb-<api.google.com>] Update balancing state to TRANSIENT_FAILURE: picks="
+ "[Status{code=UNAVAILABLE, description=www.google.com not found, cause=null}],"
+ " drops=[]")
.inOrder();
logs.clear();
RoundRobinPicker picker = (RoundRobinPicker) pickerCaptor.getValue();
assertThat(picker.dropList).isEmpty();
PickResult result = picker.pickSubchannel(mock(PickSubchannelArgs.class));
assertThat(result.getStatus().getCode()).isEqualTo(Code.UNAVAILABLE);
assertThat(result.getStatus().getDescription()).isEqualTo(error.getDescription());
// Recover with a subsequent success
List<EquivalentAddressGroup> grpclbBalancerList = createResolvedBalancerAddresses(1);
deliverResolvedAddresses(Collections.<EquivalentAddressGroup>emptyList(), grpclbBalancerList);
verify(helper).createOobChannel(eq(xattr(grpclbBalancerList)),
eq(lbAuthority(0) + NO_USE_AUTHORITY_SUFFIX));
verify(mockLbService).balanceLoad(lbResponseObserverCaptor.capture());
}
@Test
public void grpclbThenNameResolutionFails() {
InOrder inOrder = inOrder(helper, subchannelPool);
// Go to GRPCLB first
List<EquivalentAddressGroup> grpclbBalancerList = createResolvedBalancerAddresses(1);
deliverResolvedAddresses(Collections.<EquivalentAddressGroup>emptyList(), grpclbBalancerList);
verify(helper).createOobChannel(eq(xattr(grpclbBalancerList)),
eq(lbAuthority(0) + NO_USE_AUTHORITY_SUFFIX));
assertEquals(1, fakeOobChannels.size());
ManagedChannel oobChannel = fakeOobChannels.poll();
verify(mockLbService).balanceLoad(lbResponseObserverCaptor.capture());
StreamObserver<LoadBalanceResponse> lbResponseObserver = lbResponseObserverCaptor.getValue();
// Let name resolution fail before round-robin list is ready
Status error = Status.NOT_FOUND.withDescription("www.google.com not found");
deliverNameResolutionError(error);
inOrder.verify(helper).updateBalancingState(eq(TRANSIENT_FAILURE), pickerCaptor.capture());
RoundRobinPicker picker = (RoundRobinPicker) pickerCaptor.getValue();
assertThat(picker.dropList).isEmpty();
PickResult result = picker.pickSubchannel(mock(PickSubchannelArgs.class));
assertThat(result.getStatus().getCode()).isEqualTo(Code.UNAVAILABLE);
assertThat(result.getStatus().getDescription()).isEqualTo(error.getDescription());
assertFalse(oobChannel.isShutdown());
// Simulate receiving LB response
List<ServerEntry> backends = Arrays.asList(
new ServerEntry("127.0.0.1", 2000, "TOKEN1"),
new ServerEntry("127.0.0.1", 2010, "TOKEN2"));
lbResponseObserver.onNext(buildInitialResponse());
lbResponseObserver.onNext(buildLbResponse(backends));
inOrder.verify(subchannelPool).takeOrCreateSubchannel(
eq(new EquivalentAddressGroup(backends.get(0).addr, LB_BACKEND_ATTRS)),
any(Attributes.class));
inOrder.verify(subchannelPool).takeOrCreateSubchannel(
eq(new EquivalentAddressGroup(backends.get(1).addr, LB_BACKEND_ATTRS)),
any(Attributes.class));
}
@Test
public void grpclbUpdatedAddresses_avoidsReconnect() {
List<EquivalentAddressGroup> backendList = createResolvedBackendAddresses(1);
List<EquivalentAddressGroup> grpclbBalancerList = createResolvedBalancerAddresses(1);
deliverResolvedAddresses(backendList, grpclbBalancerList);
verify(helper).createOobChannel(eq(xattr(grpclbBalancerList)),
eq(lbAuthority(0) + NO_USE_AUTHORITY_SUFFIX));
ManagedChannel oobChannel = fakeOobChannels.poll();
assertEquals(1, lbRequestObservers.size());
List<EquivalentAddressGroup> backendList2 = createResolvedBackendAddresses(1);
List<EquivalentAddressGroup> grpclbBalancerList2 = createResolvedBalancerAddresses(2);
deliverResolvedAddresses(backendList2, grpclbBalancerList2);
verify(helper).updateOobChannelAddresses(eq(oobChannel), eq(xattr(grpclbBalancerList2)));
assertEquals(1, lbRequestObservers.size()); // No additional RPC
}
@Test
public void grpclbUpdatedAddresses_reconnectOnAuthorityChange() {
List<EquivalentAddressGroup> backendList = createResolvedBackendAddresses(1);
List<EquivalentAddressGroup> grpclbBalancerList = createResolvedBalancerAddresses(1);
deliverResolvedAddresses(backendList, grpclbBalancerList);
verify(helper).createOobChannel(eq(xattr(grpclbBalancerList)),
eq(lbAuthority(0) + NO_USE_AUTHORITY_SUFFIX));
ManagedChannel oobChannel = fakeOobChannels.poll();
assertEquals(1, lbRequestObservers.size());
final String newAuthority = "some-new-authority";
List<EquivalentAddressGroup> backendList2 = createResolvedBackendAddresses(1);
List<EquivalentAddressGroup> grpclbBalancerList2 =
Collections.singletonList(
new EquivalentAddressGroup(
new FakeSocketAddress("somethingNew"), lbAttributes(newAuthority)));
deliverResolvedAddresses(backendList2, grpclbBalancerList2);
verify(helper).updateOobChannelAddresses(eq(oobChannel), eq(xattr(grpclbBalancerList2)));
assertEquals(1, lbRequestObservers.size()); // No additional RPC
}
@Test
public void grpclbWorking() {
InOrder inOrder = inOrder(helper, subchannelPool);
List<EquivalentAddressGroup> grpclbBalancerList = createResolvedBalancerAddresses(1);
deliverResolvedAddresses(Collections.<EquivalentAddressGroup>emptyList(), grpclbBalancerList);
// Fallback timer is started as soon as the addresses are resolved.
assertEquals(1, fakeClock.numPendingTasks(FALLBACK_MODE_TASK_FILTER));
verify(helper).createOobChannel(eq(xattr(grpclbBalancerList)),
eq(lbAuthority(0) + NO_USE_AUTHORITY_SUFFIX));
assertEquals(1, fakeOobChannels.size());
ManagedChannel oobChannel = fakeOobChannels.poll();
verify(mockLbService).balanceLoad(lbResponseObserverCaptor.capture());
StreamObserver<LoadBalanceResponse> lbResponseObserver = lbResponseObserverCaptor.getValue();
assertEquals(1, lbRequestObservers.size());
StreamObserver<LoadBalanceRequest> lbRequestObserver = lbRequestObservers.poll();
verify(lbRequestObserver).onNext(
eq(LoadBalanceRequest.newBuilder().setInitialRequest(
InitialLoadBalanceRequest.newBuilder().setName(SERVICE_AUTHORITY).build())
.build()));
// Simulate receiving LB response
List<ServerEntry> backends1 = Arrays.asList(
new ServerEntry("127.0.0.1", 2000, "token0001"),
new ServerEntry("127.0.0.1", 2010, "token0002"));
inOrder.verify(helper, never())
.updateBalancingState(any(ConnectivityState.class), any(SubchannelPicker.class));
logs.clear();
lbResponseObserver.onNext(buildInitialResponse());
assertThat(logs).containsExactly(
"DEBUG: [grpclb-<api.google.com>] Got an LB response: " + buildInitialResponse());
logs.clear();
lbResponseObserver.onNext(buildLbResponse(backends1));
inOrder.verify(subchannelPool).takeOrCreateSubchannel(
eq(new EquivalentAddressGroup(backends1.get(0).addr, LB_BACKEND_ATTRS)),
any(Attributes.class));
inOrder.verify(subchannelPool).takeOrCreateSubchannel(
eq(new EquivalentAddressGroup(backends1.get(1).addr, LB_BACKEND_ATTRS)),
any(Attributes.class));
assertEquals(2, mockSubchannels.size());
Subchannel subchannel1 = mockSubchannels.poll();
Subchannel subchannel2 = mockSubchannels.poll();
verify(subchannel1).requestConnection();
verify(subchannel2).requestConnection();
assertEquals(
new EquivalentAddressGroup(backends1.get(0).addr, LB_BACKEND_ATTRS),
subchannel1.getAddresses());
assertEquals(
new EquivalentAddressGroup(backends1.get(1).addr, LB_BACKEND_ATTRS),
subchannel2.getAddresses());
deliverSubchannelState(subchannel1, ConnectivityStateInfo.forNonError(CONNECTING));
deliverSubchannelState(subchannel2, ConnectivityStateInfo.forNonError(CONNECTING));
inOrder.verify(helper).updateBalancingState(eq(CONNECTING), pickerCaptor.capture());
RoundRobinPicker picker0 = (RoundRobinPicker) pickerCaptor.getValue();
assertThat(picker0.dropList).containsExactly(null, null);
assertThat(picker0.pickList).containsExactly(BUFFER_ENTRY);
inOrder.verifyNoMoreInteractions();
assertThat(logs).containsExactly(
"DEBUG: [grpclb-<api.google.com>] Got an LB response: " + buildLbResponse(backends1),
"INFO: [grpclb-<api.google.com>] Using RR list="
+ "[[[/127.0.0.1:2000]/{io.grpc.grpclb.lbProvidedBackend=true}](token0001),"
+ " [[/127.0.0.1:2010]/{io.grpc.grpclb.lbProvidedBackend=true}](token0002)],"
+ " drop=[null, null]",
"INFO: [grpclb-<api.google.com>]"
+ " Update balancing state to CONNECTING: picks=[BUFFER_ENTRY], drops=[null, null]")
.inOrder();
logs.clear();
// Let subchannels be connected
deliverSubchannelState(subchannel2, ConnectivityStateInfo.forNonError(READY));
inOrder.verify(helper).updateBalancingState(eq(READY), pickerCaptor.capture());
assertThat(logs).containsExactly(
"INFO: [grpclb-<api.google.com>] Update balancing state to READY: picks="
+ "[[[[[/127.0.0.1:2010]/{io.grpc.grpclb.lbProvidedBackend=true}]](token0002)]],"
+ " drops=[null, null]");
logs.clear();
RoundRobinPicker picker1 = (RoundRobinPicker) pickerCaptor.getValue();
assertThat(picker1.dropList).containsExactly(null, null);
assertThat(picker1.pickList).containsExactly(
new BackendEntry(subchannel2, getLoadRecorder(), "token0002"));
deliverSubchannelState(subchannel1, ConnectivityStateInfo.forNonError(READY));
inOrder.verify(helper).updateBalancingState(eq(READY), pickerCaptor.capture());
assertThat(logs).containsExactly(
"INFO: [grpclb-<api.google.com>] Update balancing state to READY: picks="
+ "[[[[[/127.0.0.1:2000]/{io.grpc.grpclb.lbProvidedBackend=true}]](token0001)],"
+ " [[[[/127.0.0.1:2010]/{io.grpc.grpclb.lbProvidedBackend=true}]](token0002)]],"
+ " drops=[null, null]");
logs.clear();
RoundRobinPicker picker2 = (RoundRobinPicker) pickerCaptor.getValue();
assertThat(picker2.dropList).containsExactly(null, null);
assertThat(picker2.pickList).containsExactly(