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PriorityLoadBalancerTest.java
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PriorityLoadBalancerTest.java
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/*
* Copyright 2020 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.xds;
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.TRANSIENT_FAILURE;
import static io.grpc.xds.XdsSubchannelPickers.BUFFER_PICKER;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.eq;
import static org.mockito.Mockito.atLeastOnce;
import static org.mockito.Mockito.clearInvocations;
import static org.mockito.Mockito.doReturn;
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 com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import io.grpc.Attributes;
import io.grpc.ConnectivityState;
import io.grpc.EquivalentAddressGroup;
import io.grpc.LoadBalancer;
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.LoadBalancerProvider;
import io.grpc.Status;
import io.grpc.SynchronizationContext;
import io.grpc.internal.FakeClock;
import io.grpc.internal.ServiceConfigUtil.PolicySelection;
import io.grpc.internal.TestUtils.StandardLoadBalancerProvider;
import io.grpc.xds.PriorityLoadBalancerProvider.PriorityLbConfig;
import io.grpc.xds.PriorityLoadBalancerProvider.PriorityLbConfig.PriorityChildConfig;
import io.grpc.xds.XdsSubchannelPickers.ErrorPicker;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
import org.junit.After;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
import org.mockito.ArgumentCaptor;
import org.mockito.Captor;
import org.mockito.Mock;
import org.mockito.junit.MockitoJUnit;
import org.mockito.junit.MockitoRule;
/** Tests for {@link PriorityLoadBalancer}. */
@RunWith(JUnit4.class)
public class PriorityLoadBalancerTest {
private final List<LoadBalancer> fooBalancers = new ArrayList<>();
private final List<LoadBalancer> barBalancers = new ArrayList<>();
private final List<Helper> fooHelpers = new ArrayList<>();
private final SynchronizationContext syncContext = new SynchronizationContext(
new Thread.UncaughtExceptionHandler() {
@Override
public void uncaughtException(Thread t, Throwable e) {
throw new AssertionError(e);
}
});
private final FakeClock fakeClock = new FakeClock();
private final LoadBalancerProvider fooLbProvider =
new StandardLoadBalancerProvider("foo_policy") {
@Override
public LoadBalancer newLoadBalancer(Helper helper) {
fooHelpers.add(helper);
LoadBalancer childBalancer = mock(LoadBalancer.class);
fooBalancers.add(childBalancer);
return childBalancer;
}
};
private final LoadBalancerProvider barLbProvider =
new StandardLoadBalancerProvider("bar_policy") {
@Override
public LoadBalancer newLoadBalancer(Helper helper) {
LoadBalancer childBalancer = mock(LoadBalancer.class);
barBalancers.add(childBalancer);
return childBalancer;
}
};
@Rule public final MockitoRule mockitoRule = MockitoJUnit.rule();
@Mock private Helper helper;
@Captor ArgumentCaptor<ResolvedAddresses> resolvedAddressesCaptor;
@Captor ArgumentCaptor<ConnectivityState> connectivityStateCaptor;
@Captor ArgumentCaptor<SubchannelPicker> pickerCaptor;
private PriorityLoadBalancer priorityLb;
@Before
public void setUp() {
doReturn(syncContext).when(helper).getSynchronizationContext();
doReturn(fakeClock.getScheduledExecutorService()).when(helper).getScheduledExecutorService();
priorityLb = new PriorityLoadBalancer(helper);
clearInvocations(helper);
}
@After
public void tearDown() {
priorityLb.shutdown();
for (LoadBalancer lb : fooBalancers) {
verify(lb).shutdown();
}
for (LoadBalancer lb : barBalancers) {
verify(lb).shutdown();
}
assertThat(fakeClock.getPendingTasks()).isEmpty();
}
@Test
public void handleResolvedAddresses() {
SocketAddress socketAddress = new InetSocketAddress(8080);
EquivalentAddressGroup eag = new EquivalentAddressGroup(socketAddress);
eag = AddressFilter.setPathFilter(eag, ImmutableList.of("p1"));
List<EquivalentAddressGroup> addresses = ImmutableList.of(eag);
Attributes attributes =
Attributes.newBuilder().set(Attributes.Key.create("fakeKey"), "fakeValue").build();
Object fooConfig0 = new Object();
PriorityChildConfig priorityChildConfig0 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, fooConfig0), true);
Object barConfig0 = new Object();
PriorityChildConfig priorityChildConfig1 =
new PriorityChildConfig(new PolicySelection(barLbProvider, barConfig0), true);
Object fooConfig1 = new Object();
PriorityChildConfig priorityChildConfig2 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, fooConfig1), true);
PriorityLbConfig priorityLbConfig =
new PriorityLbConfig(
ImmutableMap.of("p0", priorityChildConfig0, "p1", priorityChildConfig1,
"p2", priorityChildConfig2),
ImmutableList.of("p0", "p1", "p2"));
priorityLb.handleResolvedAddresses(
ResolvedAddresses.newBuilder()
.setAddresses(addresses)
.setAttributes(attributes)
.setLoadBalancingPolicyConfig(priorityLbConfig)
.build());
assertThat(fooBalancers).hasSize(1);
assertThat(barBalancers).isEmpty();
LoadBalancer fooBalancer0 = Iterables.getOnlyElement(fooBalancers);
verify(fooBalancer0).handleResolvedAddresses(resolvedAddressesCaptor.capture());
ResolvedAddresses addressesReceived = resolvedAddressesCaptor.getValue();
assertThat(addressesReceived.getAddresses()).isEmpty();
assertThat(addressesReceived.getAttributes()).isEqualTo(attributes);
assertThat(addressesReceived.getLoadBalancingPolicyConfig()).isEqualTo(fooConfig0);
// Fail over to p1.
fakeClock.forwardTime(10, TimeUnit.SECONDS);
assertThat(fooBalancers).hasSize(1);
assertThat(barBalancers).hasSize(1);
LoadBalancer barBalancer0 = Iterables.getOnlyElement(barBalancers);
verify(barBalancer0).handleResolvedAddresses(resolvedAddressesCaptor.capture());
addressesReceived = resolvedAddressesCaptor.getValue();
assertThat(Iterables.getOnlyElement(addressesReceived.getAddresses()).getAddresses())
.containsExactly(socketAddress);
assertThat(addressesReceived.getAttributes()).isEqualTo(attributes);
assertThat(addressesReceived.getLoadBalancingPolicyConfig()).isEqualTo(barConfig0);
// Fail over to p2.
fakeClock.forwardTime(10, TimeUnit.SECONDS);
assertThat(fooBalancers).hasSize(2);
assertThat(barBalancers).hasSize(1);
LoadBalancer fooBalancer1 = Iterables.getLast(fooBalancers);
verify(fooBalancer1).handleResolvedAddresses(resolvedAddressesCaptor.capture());
addressesReceived = resolvedAddressesCaptor.getValue();
assertThat(addressesReceived.getAddresses()).isEmpty();
assertThat(addressesReceived.getAttributes()).isEqualTo(attributes);
assertThat(addressesReceived.getLoadBalancingPolicyConfig()).isEqualTo(fooConfig1);
// New update: p0 and p2 deleted; p1 config changed.
SocketAddress newSocketAddress = new InetSocketAddress(8081);
EquivalentAddressGroup newEag = new EquivalentAddressGroup(newSocketAddress);
newEag = AddressFilter.setPathFilter(newEag, ImmutableList.of("p1"));
List<EquivalentAddressGroup> newAddresses = ImmutableList.of(newEag);
Object newBarConfig = new Object();
PriorityLbConfig newPriorityLbConfig =
new PriorityLbConfig(
ImmutableMap.of("p1",
new PriorityChildConfig(new PolicySelection(barLbProvider, newBarConfig), true)),
ImmutableList.of("p1"));
priorityLb.handleResolvedAddresses(
ResolvedAddresses.newBuilder()
.setAddresses(newAddresses)
.setLoadBalancingPolicyConfig(newPriorityLbConfig)
.build());
assertThat(fooBalancers).hasSize(2);
assertThat(barBalancers).hasSize(1);
verify(barBalancer0, times(2)).handleResolvedAddresses(resolvedAddressesCaptor.capture());
addressesReceived = resolvedAddressesCaptor.getValue();
assertThat(Iterables.getOnlyElement(addressesReceived.getAddresses()).getAddresses())
.containsExactly(newSocketAddress);
assertThat(addressesReceived.getAttributes()).isEqualTo(Attributes.EMPTY);
assertThat(addressesReceived.getLoadBalancingPolicyConfig()).isEqualTo(newBarConfig);
verify(fooBalancer0, never()).shutdown();
verify(fooBalancer1, never()).shutdown();
fakeClock.forwardTime(15, TimeUnit.MINUTES);
verify(fooBalancer0).shutdown();
verify(fooBalancer1).shutdown();
verify(barBalancer0, never()).shutdown();
}
@Test
public void handleNameResolutionError() {
Object fooConfig0 = new Object();
PriorityChildConfig priorityChildConfig0 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, fooConfig0), true);
Object fooConfig1 = new Object();
PriorityChildConfig priorityChildConfig1 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, fooConfig1), true);
PriorityLbConfig priorityLbConfig =
new PriorityLbConfig(ImmutableMap.of("p0", priorityChildConfig0), ImmutableList.of("p0"));
priorityLb.handleResolvedAddresses(
ResolvedAddresses.newBuilder()
.setAddresses(ImmutableList.<EquivalentAddressGroup>of())
.setLoadBalancingPolicyConfig(priorityLbConfig)
.build());
LoadBalancer fooLb0 = Iterables.getOnlyElement(fooBalancers);
Status status = Status.DATA_LOSS.withDescription("fake error");
priorityLb.handleNameResolutionError(status);
verify(fooLb0).handleNameResolutionError(status);
priorityLbConfig =
new PriorityLbConfig(ImmutableMap.of("p1", priorityChildConfig1), ImmutableList.of("p1"));
priorityLb.handleResolvedAddresses(
ResolvedAddresses.newBuilder()
.setAddresses(ImmutableList.<EquivalentAddressGroup>of())
.setLoadBalancingPolicyConfig(priorityLbConfig)
.build());
assertThat(fooBalancers).hasSize(2);
LoadBalancer fooLb1 = Iterables.getLast(fooBalancers);
status = Status.UNAVAILABLE.withDescription("fake error");
priorityLb.handleNameResolutionError(status);
// fooLb0 is deactivated but not yet deleted. However, because it is delisted by the latest
// address update, name resolution error will not be propagated to it.
verify(fooLb0, never()).shutdown();
verify(fooLb0, never()).handleNameResolutionError(status);
verify(fooLb1).handleNameResolutionError(status);
}
@Test
public void typicalPriorityFailOverFlow() {
PriorityChildConfig priorityChildConfig0 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityChildConfig priorityChildConfig1 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityChildConfig priorityChildConfig2 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityChildConfig priorityChildConfig3 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityLbConfig priorityLbConfig =
new PriorityLbConfig(
ImmutableMap.of("p0", priorityChildConfig0, "p1", priorityChildConfig1,
"p2", priorityChildConfig2, "p3", priorityChildConfig3),
ImmutableList.of("p0", "p1", "p2", "p3"));
priorityLb.handleResolvedAddresses(
ResolvedAddresses.newBuilder()
.setAddresses(ImmutableList.<EquivalentAddressGroup>of())
.setLoadBalancingPolicyConfig(priorityLbConfig)
.build());
assertThat(fooBalancers).hasSize(1);
assertThat(fooHelpers).hasSize(1);
LoadBalancer balancer0 = Iterables.getLast(fooBalancers);
Helper helper0 = Iterables.getOnlyElement(fooHelpers);
// p0 gets READY.
final Subchannel subchannel0 = mock(Subchannel.class);
helper0.updateBalancingState(
READY,
new SubchannelPicker() {
@Override
public PickResult pickSubchannel(PickSubchannelArgs args) {
return PickResult.withSubchannel(subchannel0);
}
});
assertCurrentPickerPicksSubchannel(subchannel0);
// p0 fails over to p1 immediately.
helper0.updateBalancingState(TRANSIENT_FAILURE, new ErrorPicker(Status.ABORTED));
assertLatestConnectivityState(CONNECTING);
assertThat(fooBalancers).hasSize(2);
assertThat(fooHelpers).hasSize(2);
LoadBalancer balancer1 = Iterables.getLast(fooBalancers);
// p1 timeout, and fails over to p2
fakeClock.forwardTime(10, TimeUnit.SECONDS);
assertLatestConnectivityState(CONNECTING);
assertThat(fooBalancers).hasSize(3);
assertThat(fooHelpers).hasSize(3);
LoadBalancer balancer2 = Iterables.getLast(fooBalancers);
Helper helper2 = Iterables.getLast(fooHelpers);
// p2 gets READY
final Subchannel subchannel1 = mock(Subchannel.class);
helper2.updateBalancingState(
READY,
new SubchannelPicker() {
@Override
public PickResult pickSubchannel(PickSubchannelArgs args) {
return PickResult.withSubchannel(subchannel1);
}
});
assertCurrentPickerPicksSubchannel(subchannel1);
// p0 gets back to READY
final Subchannel subchannel2 = mock(Subchannel.class);
helper0.updateBalancingState(
READY,
new SubchannelPicker() {
@Override
public PickResult pickSubchannel(PickSubchannelArgs args) {
return PickResult.withSubchannel(subchannel2);
}
});
assertCurrentPickerPicksSubchannel(subchannel2);
// p2 fails but does not affect overall picker
helper2.updateBalancingState(TRANSIENT_FAILURE, new ErrorPicker(Status.UNAVAILABLE));
assertCurrentPickerPicksSubchannel(subchannel2);
// p0 fails over to p3 immediately since p1 already timeout and p2 already in TRANSIENT_FAILURE.
helper0.updateBalancingState(TRANSIENT_FAILURE, new ErrorPicker(Status.UNAVAILABLE));
assertLatestConnectivityState(CONNECTING);
assertThat(fooBalancers).hasSize(4);
assertThat(fooHelpers).hasSize(4);
LoadBalancer balancer3 = Iterables.getLast(fooBalancers);
Helper helper3 = Iterables.getLast(fooHelpers);
// p3 timeout then the channel should go to TRANSIENT_FAILURE
fakeClock.forwardTime(10, TimeUnit.SECONDS);
assertCurrentPickerReturnsError(Status.Code.UNAVAILABLE, "timeout");
// p3 fails then the picker should have error status updated
helper3.updateBalancingState(
TRANSIENT_FAILURE, new ErrorPicker(Status.DATA_LOSS.withDescription("foo")));
assertCurrentPickerReturnsError(Status.Code.DATA_LOSS, "foo");
// p2 gets back to READY
final Subchannel subchannel3 = mock(Subchannel.class);
helper2.updateBalancingState(
READY,
new SubchannelPicker() {
@Override
public PickResult pickSubchannel(PickSubchannelArgs args) {
return PickResult.withSubchannel(subchannel3);
}
});
assertCurrentPickerPicksSubchannel(subchannel3);
// p0 gets back to READY
final Subchannel subchannel4 = mock(Subchannel.class);
helper0.updateBalancingState(
READY,
new SubchannelPicker() {
@Override
public PickResult pickSubchannel(PickSubchannelArgs args) {
return PickResult.withSubchannel(subchannel4);
}
});
assertCurrentPickerPicksSubchannel(subchannel4);
// p0 fails over to p2 and picker is updated to p2's existing picker.
helper0.updateBalancingState(TRANSIENT_FAILURE, new ErrorPicker(Status.UNAVAILABLE));
assertCurrentPickerPicksSubchannel(subchannel3);
// Deactivate child balancer get deleted.
fakeClock.forwardTime(15, TimeUnit.MINUTES);
verify(balancer0, never()).shutdown();
verify(balancer1, never()).shutdown();
verify(balancer2, never()).shutdown();
verify(balancer3).shutdown();
}
@Test
public void idleToConnectingDoesNotTriggerFailOver() {
PriorityChildConfig priorityChildConfig0 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityChildConfig priorityChildConfig1 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityLbConfig priorityLbConfig =
new PriorityLbConfig(
ImmutableMap.of("p0", priorityChildConfig0, "p1", priorityChildConfig1),
ImmutableList.of("p0", "p1"));
priorityLb.handleResolvedAddresses(
ResolvedAddresses.newBuilder()
.setAddresses(ImmutableList.<EquivalentAddressGroup>of())
.setLoadBalancingPolicyConfig(priorityLbConfig)
.build());
assertThat(fooBalancers).hasSize(1);
assertThat(fooHelpers).hasSize(1);
Helper helper0 = Iterables.getOnlyElement(fooHelpers);
// p0 gets IDLE.
helper0.updateBalancingState(
IDLE,
BUFFER_PICKER);
assertCurrentPickerIsBufferPicker();
// p0 goes to CONNECTING
helper0.updateBalancingState(
IDLE,
BUFFER_PICKER);
assertCurrentPickerIsBufferPicker();
// no failover happened
assertThat(fooBalancers).hasSize(1);
assertThat(fooHelpers).hasSize(1);
}
@Test
public void connectingResetFailOverIfSeenReadyOrIdleSinceTransientFailure() {
PriorityChildConfig priorityChildConfig0 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityChildConfig priorityChildConfig1 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityLbConfig priorityLbConfig =
new PriorityLbConfig(
ImmutableMap.of("p0", priorityChildConfig0, "p1", priorityChildConfig1),
ImmutableList.of("p0", "p1"));
priorityLb.handleResolvedAddresses(
ResolvedAddresses.newBuilder()
.setAddresses(ImmutableList.<EquivalentAddressGroup>of())
.setLoadBalancingPolicyConfig(priorityLbConfig)
.build());
assertThat(fooBalancers).hasSize(1);
assertThat(fooHelpers).hasSize(1);
Helper helper0 = Iterables.getOnlyElement(fooHelpers);
// p0 gets IDLE.
helper0.updateBalancingState(
IDLE,
BUFFER_PICKER);
assertCurrentPickerIsBufferPicker();
// p0 goes to CONNECTING, reset failover timer
fakeClock.forwardTime(5, TimeUnit.SECONDS);
helper0.updateBalancingState(
CONNECTING,
BUFFER_PICKER);
verify(helper, times(2)).updateBalancingState(eq(CONNECTING), eq(BUFFER_PICKER));
// failover happens
fakeClock.forwardTime(10, TimeUnit.SECONDS);
assertThat(fooBalancers).hasSize(2);
assertThat(fooHelpers).hasSize(2);
}
@Test
public void readyToConnectDoesNotFailOverButUpdatesPicker() {
PriorityChildConfig priorityChildConfig0 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityChildConfig priorityChildConfig1 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityLbConfig priorityLbConfig =
new PriorityLbConfig(
ImmutableMap.of("p0", priorityChildConfig0, "p1", priorityChildConfig1),
ImmutableList.of("p0", "p1"));
priorityLb.handleResolvedAddresses(
ResolvedAddresses.newBuilder()
.setAddresses(ImmutableList.<EquivalentAddressGroup>of())
.setLoadBalancingPolicyConfig(priorityLbConfig)
.build());
assertThat(fooBalancers).hasSize(1);
assertThat(fooHelpers).hasSize(1);
Helper helper0 = Iterables.getOnlyElement(fooHelpers);
// p0 gets READY.
final Subchannel subchannel0 = mock(Subchannel.class);
helper0.updateBalancingState(
READY,
new SubchannelPicker() {
@Override
public PickResult pickSubchannel(PickSubchannelArgs args) {
return PickResult.withSubchannel(subchannel0);
}
});
assertCurrentPickerPicksSubchannel(subchannel0);
// p0 goes to CONNECTING
helper0.updateBalancingState(
IDLE,
BUFFER_PICKER);
assertCurrentPickerIsBufferPicker();
// no failover happened
assertThat(fooBalancers).hasSize(1);
assertThat(fooHelpers).hasSize(1);
// resolution update without priority change does not trigger failover
Attributes.Key<String> fooKey = Attributes.Key.create("fooKey");
priorityLb.handleResolvedAddresses(
ResolvedAddresses.newBuilder()
.setAddresses(ImmutableList.<EquivalentAddressGroup>of())
.setLoadBalancingPolicyConfig(priorityLbConfig)
.setAttributes(Attributes.newBuilder().set(fooKey, "barVal").build())
.build());
assertCurrentPickerIsBufferPicker();
// no failover happened
assertThat(fooBalancers).hasSize(1);
assertThat(fooHelpers).hasSize(1);
}
@Test
public void typicalPriorityFailOverFlowWithIdleUpdate() {
PriorityChildConfig priorityChildConfig0 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityChildConfig priorityChildConfig1 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityChildConfig priorityChildConfig2 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityChildConfig priorityChildConfig3 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityLbConfig priorityLbConfig =
new PriorityLbConfig(
ImmutableMap.of("p0", priorityChildConfig0, "p1", priorityChildConfig1,
"p2", priorityChildConfig2, "p3", priorityChildConfig3),
ImmutableList.of("p0", "p1", "p2", "p3"));
priorityLb.handleResolvedAddresses(
ResolvedAddresses.newBuilder()
.setAddresses(ImmutableList.<EquivalentAddressGroup>of())
.setLoadBalancingPolicyConfig(priorityLbConfig)
.build());
assertThat(fooBalancers).hasSize(1);
assertThat(fooHelpers).hasSize(1);
LoadBalancer balancer0 = Iterables.getLast(fooBalancers);
Helper helper0 = Iterables.getOnlyElement(fooHelpers);
// p0 gets IDLE.
helper0.updateBalancingState(
IDLE,
BUFFER_PICKER);
assertCurrentPickerIsBufferPicker();
// p0 fails over to p1 immediately.
helper0.updateBalancingState(TRANSIENT_FAILURE, new ErrorPicker(Status.ABORTED));
assertLatestConnectivityState(CONNECTING);
assertThat(fooBalancers).hasSize(2);
assertThat(fooHelpers).hasSize(2);
LoadBalancer balancer1 = Iterables.getLast(fooBalancers);
// p1 timeout, and fails over to p2
fakeClock.forwardTime(10, TimeUnit.SECONDS);
assertLatestConnectivityState(CONNECTING);
assertThat(fooBalancers).hasSize(3);
assertThat(fooHelpers).hasSize(3);
LoadBalancer balancer2 = Iterables.getLast(fooBalancers);
Helper helper2 = Iterables.getLast(fooHelpers);
// p2 gets IDLE
helper2.updateBalancingState(
IDLE,
BUFFER_PICKER);
assertCurrentPickerIsBufferPicker();
// p0 gets back to IDLE
helper0.updateBalancingState(
IDLE,
BUFFER_PICKER);
assertCurrentPickerIsBufferPicker();
// p2 fails but does not affect overall picker
helper2.updateBalancingState(TRANSIENT_FAILURE, new ErrorPicker(Status.UNAVAILABLE));
assertCurrentPickerIsBufferPicker();
// p0 fails over to p3 immediately since p1 already timeout and p2 already in TRANSIENT_FAILURE.
helper0.updateBalancingState(TRANSIENT_FAILURE, new ErrorPicker(Status.UNAVAILABLE));
assertLatestConnectivityState(CONNECTING);
assertThat(fooBalancers).hasSize(4);
assertThat(fooHelpers).hasSize(4);
LoadBalancer balancer3 = Iterables.getLast(fooBalancers);
Helper helper3 = Iterables.getLast(fooHelpers);
// p3 timeout then the channel should go to TRANSIENT_FAILURE
fakeClock.forwardTime(10, TimeUnit.SECONDS);
assertCurrentPickerReturnsError(Status.Code.UNAVAILABLE, "timeout");
// p3 fails then the picker should have error status updated
helper3.updateBalancingState(
TRANSIENT_FAILURE, new ErrorPicker(Status.DATA_LOSS.withDescription("foo")));
assertCurrentPickerReturnsError(Status.Code.DATA_LOSS, "foo");
// p2 gets back to IDLE
helper2.updateBalancingState(
IDLE,
BUFFER_PICKER);
assertCurrentPickerIsBufferPicker();
// p0 gets back to IDLE
helper0.updateBalancingState(
IDLE,
BUFFER_PICKER);
assertCurrentPickerIsBufferPicker();
// p0 fails over to p2 and picker is updated to p2's existing picker.
helper0.updateBalancingState(TRANSIENT_FAILURE, new ErrorPicker(Status.UNAVAILABLE));
assertCurrentPickerIsBufferPicker();
// Deactivate child balancer get deleted.
fakeClock.forwardTime(15, TimeUnit.MINUTES);
verify(balancer0, never()).shutdown();
verify(balancer1, never()).shutdown();
verify(balancer2, never()).shutdown();
verify(balancer3).shutdown();
}
@Test
public void bypassReresolutionRequestsIfConfiged() {
PriorityChildConfig priorityChildConfig0 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityChildConfig priorityChildConfig1 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), false);
PriorityLbConfig priorityLbConfig =
new PriorityLbConfig(
ImmutableMap.of("p0", priorityChildConfig0, "p1", priorityChildConfig1),
ImmutableList.of("p0", "p1"));
priorityLb.handleResolvedAddresses(
ResolvedAddresses.newBuilder()
.setAddresses(ImmutableList.<EquivalentAddressGroup>of())
.setLoadBalancingPolicyConfig(priorityLbConfig)
.build());
Helper priorityHelper0 = Iterables.getOnlyElement(fooHelpers); // priority p0
priorityHelper0.refreshNameResolution();
verify(helper, never()).refreshNameResolution();
// Simulate fallback to priority p1.
priorityHelper0.updateBalancingState(TRANSIENT_FAILURE, new ErrorPicker(Status.UNAVAILABLE));
assertThat(fooHelpers).hasSize(2);
Helper priorityHelper1 = Iterables.getLast(fooHelpers);
priorityHelper1.refreshNameResolution();
verify(helper).refreshNameResolution();
}
@Test
public void raceBetweenShutdownAndChildLbBalancingStateUpdate() {
PriorityChildConfig priorityChildConfig0 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), true);
PriorityChildConfig priorityChildConfig1 =
new PriorityChildConfig(new PolicySelection(fooLbProvider, new Object()), false);
PriorityLbConfig priorityLbConfig =
new PriorityLbConfig(
ImmutableMap.of("p0", priorityChildConfig0, "p1", priorityChildConfig1),
ImmutableList.of("p0", "p1"));
priorityLb.handleResolvedAddresses(
ResolvedAddresses.newBuilder()
.setAddresses(ImmutableList.<EquivalentAddressGroup>of())
.setLoadBalancingPolicyConfig(priorityLbConfig)
.build());
verify(helper).updateBalancingState(eq(CONNECTING), eq(BUFFER_PICKER));
// LB shutdown and subchannel state change can happen simultaneously. If shutdown runs first,
// any further balancing state update should be ignored.
priorityLb.shutdown();
Helper priorityHelper0 = Iterables.getOnlyElement(fooHelpers); // priority p0
priorityHelper0.updateBalancingState(READY, mock(SubchannelPicker.class));
verifyNoMoreInteractions(helper);
}
@Test
public void noDuplicateOverallBalancingStateUpdate() {
FakeLoadBalancerProvider fakeLbProvider = new FakeLoadBalancerProvider();
PriorityChildConfig priorityChildConfig0 =
new PriorityChildConfig(new PolicySelection(fakeLbProvider, new Object()), true);
PriorityChildConfig priorityChildConfig1 =
new PriorityChildConfig(new PolicySelection(fakeLbProvider, new Object()), false);
PriorityLbConfig priorityLbConfig =
new PriorityLbConfig(
ImmutableMap.of("p0", priorityChildConfig0, "p1", priorityChildConfig1),
ImmutableList.of("p0", "p1"));
priorityLb.handleResolvedAddresses(
ResolvedAddresses.newBuilder()
.setAddresses(ImmutableList.<EquivalentAddressGroup>of())
.setLoadBalancingPolicyConfig(priorityLbConfig)
.build());
verify(helper, times(1)).updateBalancingState(any(), any());
}
private void assertLatestConnectivityState(ConnectivityState expectedState) {
verify(helper, atLeastOnce())
.updateBalancingState(connectivityStateCaptor.capture(), pickerCaptor.capture());
assertThat(connectivityStateCaptor.getValue()).isEqualTo(expectedState);
}
private void assertCurrentPickerReturnsError(
Status.Code expectedCode, String expectedDescription) {
assertLatestConnectivityState(TRANSIENT_FAILURE);
Status error =
pickerCaptor.getValue().pickSubchannel(mock(PickSubchannelArgs.class)).getStatus();
assertThat(error.getCode()).isEqualTo(expectedCode);
if (expectedDescription != null) {
assertThat(error.getDescription()).contains(expectedDescription);
}
}
private void assertCurrentPickerPicksSubchannel(Subchannel expectedSubchannelToPick) {
assertLatestConnectivityState(READY);
PickResult pickResult = pickerCaptor.getValue().pickSubchannel(mock(PickSubchannelArgs.class));
assertThat(pickResult.getSubchannel()).isEqualTo(expectedSubchannelToPick);
}
private void assertCurrentPickerIsBufferPicker() {
assertLatestConnectivityState(IDLE);
PickResult pickResult = pickerCaptor.getValue().pickSubchannel(mock(PickSubchannelArgs.class));
assertThat(pickResult).isEqualTo(PickResult.withNoResult());
}
private static class FakeLoadBalancerProvider extends LoadBalancerProvider {
@Override
public boolean isAvailable() {
return true;
}
@Override
public int getPriority() {
return 5;
}
@Override
public String getPolicyName() {
return "foo";
}
@Override
public LoadBalancer newLoadBalancer(Helper helper) {
return new FakeLoadBalancer(helper);
}
}
static class FakeLoadBalancer extends LoadBalancer {
private Helper helper;
FakeLoadBalancer(Helper helper) {
this.helper = helper;
}
@Override
public void handleResolvedAddresses(ResolvedAddresses resolvedAddresses) {
helper.updateBalancingState(TRANSIENT_FAILURE, new ErrorPicker(Status.INTERNAL));
}
@Override
public void handleNameResolutionError(Status error) {
}
@Override
public void shutdown() {
}
}
}