util: Remove GracefulSwitchLb.switchTo()

It was deprecated in 85e0a01ec, so has been deprecated for six
releases/over six months.
This commit is contained in:
Eric Anderson 2025-02-20 13:03:10 -08:00
parent 892144dcac
commit f207be39a9
2 changed files with 2 additions and 484 deletions

View File

@ -44,28 +44,14 @@ import javax.annotation.concurrent.NotThreadSafe;
* generally created by calling {@link #parseLoadBalancingPolicyConfig(List)} from a
* {@link io.grpc.LoadBalancerProvider#parseLoadBalancingPolicyConfig
* provider's parseLoadBalancingPolicyConfig()} implementation.
*
* <p>Alternatively, the balancer may {@link #switchTo(LoadBalancer.Factory) switch to} a policy
* prior to {@link
* LoadBalancer#handleResolvedAddresses(ResolvedAddresses) handling resolved addresses} for the
* first time. This causes graceful switch to ignore the service config and pass through the
* resolved addresses directly to the child policy.
*/
@ExperimentalApi("https://github.com/grpc/grpc-java/issues/5999")
@NotThreadSafe // Must be accessed in SynchronizationContext
public final class GracefulSwitchLoadBalancer extends ForwardingLoadBalancer {
private final LoadBalancer defaultBalancer = new LoadBalancer() {
@Override
public void handleResolvedAddresses(ResolvedAddresses resolvedAddresses) {
// Most LB policies using this class will receive child policy configuration within the
// service config, so they are naturally calling switchTo() just before
// handleResolvedAddresses(), within their own handleResolvedAddresses(). If switchTo() is
// not called immediately after construction that does open up potential for bugs in the
// parent policies, where they fail to call switchTo(). So we will use the exception to try
// to notice those bugs quickly, as it will fail very loudly.
throw new IllegalStateException(
"GracefulSwitchLoadBalancer must switch to a load balancing policy before handling"
+ " ResolvedAddresses");
public Status acceptResolvedAddresses(ResolvedAddresses resolvedAddresses) {
throw new AssertionError("real LB is called instead");
}
@Override
@ -104,7 +90,6 @@ public final class GracefulSwitchLoadBalancer extends ForwardingLoadBalancer {
private LoadBalancer pendingLb = defaultBalancer;
private ConnectivityState pendingState;
private SubchannelPicker pendingPicker;
private boolean switchToCalled;
private boolean currentLbIsReady;
@ -114,10 +99,6 @@ public final class GracefulSwitchLoadBalancer extends ForwardingLoadBalancer {
@Override
public void handleResolvedAddresses(ResolvedAddresses resolvedAddresses) {
if (switchToCalled) {
delegate().handleResolvedAddresses(resolvedAddresses);
return;
}
Config config = (Config) resolvedAddresses.getLoadBalancingPolicyConfig();
switchToInternal(config.childFactory);
delegate().handleResolvedAddresses(
@ -128,9 +109,6 @@ public final class GracefulSwitchLoadBalancer extends ForwardingLoadBalancer {
@Override
public Status acceptResolvedAddresses(ResolvedAddresses resolvedAddresses) {
if (switchToCalled) {
return delegate().acceptResolvedAddresses(resolvedAddresses);
}
Config config = (Config) resolvedAddresses.getLoadBalancingPolicyConfig();
switchToInternal(config.childFactory);
return delegate().acceptResolvedAddresses(
@ -139,19 +117,6 @@ public final class GracefulSwitchLoadBalancer extends ForwardingLoadBalancer {
.build());
}
/**
* Gracefully switch to a new policy defined by the given factory, if the given factory isn't
* equal to the current one.
*
* @deprecated Use {@code parseLoadBalancingPolicyConfig()} and pass the configuration to
* {@link io.grpc.LoadBalancer.ResolvedAddresses.Builder#setLoadBalancingPolicyConfig}
*/
@Deprecated
public void switchTo(LoadBalancer.Factory newBalancerFactory) {
switchToCalled = true;
switchToInternal(newBalancerFactory);
}
private void switchToInternal(LoadBalancer.Factory newBalancerFactory) {
checkNotNull(newBalancerFactory, "newBalancerFactory");

View File

@ -83,453 +83,6 @@ public class GracefulSwitchLoadBalancerTest {
new FakeLoadBalancerProvider("lb_policy_3"),
};
// OLD TESTS
@Test
@Deprecated
public void switchTo_canHandleEmptyAddressListFromNameResolutionForwardedToLatestPolicy() {
gracefulSwitchLb.switchTo(lbPolicies[0]);
LoadBalancer lb0 = balancers.get(lbPolicies[0]);
Helper helper0 = helpers.get(lb0);
SubchannelPicker picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(READY, picker);
assertThat(gracefulSwitchLb.canHandleEmptyAddressListFromNameResolution()).isFalse();
when(lb0.canHandleEmptyAddressListFromNameResolution()).thenReturn(true);
assertThat(gracefulSwitchLb.canHandleEmptyAddressListFromNameResolution()).isTrue();
gracefulSwitchLb.switchTo(lbPolicies[1]);
LoadBalancer lb1 = balancers.get(lbPolicies[1]);
assertThat(gracefulSwitchLb.canHandleEmptyAddressListFromNameResolution()).isFalse();
when(lb1.canHandleEmptyAddressListFromNameResolution()).thenReturn(true);
assertThat(gracefulSwitchLb.canHandleEmptyAddressListFromNameResolution()).isTrue();
gracefulSwitchLb.switchTo(lbPolicies[2]);
LoadBalancer lb2 = balancers.get(lbPolicies[2]);
assertThat(gracefulSwitchLb.canHandleEmptyAddressListFromNameResolution()).isFalse();
when(lb2.canHandleEmptyAddressListFromNameResolution()).thenReturn(true);
assertThat(gracefulSwitchLb.canHandleEmptyAddressListFromNameResolution()).isTrue();
}
@Test
@Deprecated
public void switchTo_handleResolvedAddressesAndNameResolutionErrorForwardedToLatestPolicy() {
gracefulSwitchLb.switchTo(lbPolicies[0]);
LoadBalancer lb0 = balancers.get(lbPolicies[0]);
Helper helper0 = helpers.get(lb0);
SubchannelPicker picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(READY, picker);
ResolvedAddresses addresses = newFakeAddresses();
gracefulSwitchLb.handleResolvedAddresses(addresses);
verify(lb0).handleResolvedAddresses(addresses);
gracefulSwitchLb.handleNameResolutionError(Status.DATA_LOSS);
verify(lb0).handleNameResolutionError(Status.DATA_LOSS);
gracefulSwitchLb.switchTo(lbPolicies[1]);
LoadBalancer lb1 = balancers.get(lbPolicies[1]);
addresses = newFakeAddresses();
gracefulSwitchLb.handleResolvedAddresses(addresses);
verify(lb0, never()).handleResolvedAddresses(addresses);
verify(lb1).handleResolvedAddresses(addresses);
gracefulSwitchLb.handleNameResolutionError(Status.ALREADY_EXISTS);
verify(lb0, never()).handleNameResolutionError(Status.ALREADY_EXISTS);
verify(lb1).handleNameResolutionError(Status.ALREADY_EXISTS);
gracefulSwitchLb.switchTo(lbPolicies[2]);
verify(lb1).shutdown();
LoadBalancer lb2 = balancers.get(lbPolicies[2]);
addresses = newFakeAddresses();
gracefulSwitchLb.handleResolvedAddresses(addresses);
verify(lb0, never()).handleResolvedAddresses(addresses);
verify(lb1, never()).handleResolvedAddresses(addresses);
verify(lb2).handleResolvedAddresses(addresses);
gracefulSwitchLb.handleNameResolutionError(Status.CANCELLED);
verify(lb0, never()).handleNameResolutionError(Status.CANCELLED);
verify(lb1, never()).handleNameResolutionError(Status.CANCELLED);
verify(lb2).handleNameResolutionError(Status.CANCELLED);
verifyNoMoreInteractions(lb0, lb1, lb2);
}
@Test
@Deprecated
public void switchTo_acceptResolvedAddressesAndNameResolutionErrorForwardedToLatestPolicy() {
gracefulSwitchLb.switchTo(lbPolicies[0]);
LoadBalancer lb0 = balancers.get(lbPolicies[0]);
Helper helper0 = helpers.get(lb0);
SubchannelPicker picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(READY, picker);
ResolvedAddresses addresses = newFakeAddresses();
gracefulSwitchLb.acceptResolvedAddresses(addresses);
verify(lb0).acceptResolvedAddresses(addresses);
gracefulSwitchLb.handleNameResolutionError(Status.DATA_LOSS);
verify(lb0).handleNameResolutionError(Status.DATA_LOSS);
gracefulSwitchLb.switchTo(lbPolicies[1]);
LoadBalancer lb1 = balancers.get(lbPolicies[1]);
addresses = newFakeAddresses();
gracefulSwitchLb.acceptResolvedAddresses(addresses);
verify(lb0, never()).acceptResolvedAddresses(addresses);
verify(lb1).acceptResolvedAddresses(addresses);
gracefulSwitchLb.handleNameResolutionError(Status.ALREADY_EXISTS);
verify(lb0, never()).handleNameResolutionError(Status.ALREADY_EXISTS);
verify(lb1).handleNameResolutionError(Status.ALREADY_EXISTS);
gracefulSwitchLb.switchTo(lbPolicies[2]);
verify(lb1).shutdown();
LoadBalancer lb2 = balancers.get(lbPolicies[2]);
addresses = newFakeAddresses();
gracefulSwitchLb.acceptResolvedAddresses(addresses);
verify(lb0, never()).acceptResolvedAddresses(addresses);
verify(lb1, never()).acceptResolvedAddresses(addresses);
verify(lb2).acceptResolvedAddresses(addresses);
gracefulSwitchLb.handleNameResolutionError(Status.CANCELLED);
verify(lb0, never()).handleNameResolutionError(Status.CANCELLED);
verify(lb1, never()).handleNameResolutionError(Status.CANCELLED);
verify(lb2).handleNameResolutionError(Status.CANCELLED);
verifyNoMoreInteractions(lb0, lb1, lb2);
}
@Test
@Deprecated
public void switchTo_shutdownTriggeredWhenSwitchAndForwardedWhenSwitchLbShutdown() {
gracefulSwitchLb.switchTo(lbPolicies[0]);
LoadBalancer lb0 = balancers.get(lbPolicies[0]);
Helper helper0 = helpers.get(lb0);
SubchannelPicker picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(READY, picker);
gracefulSwitchLb.switchTo(lbPolicies[1]);
LoadBalancer lb1 = balancers.get(lbPolicies[1]);
verify(lb1, never()).shutdown();
gracefulSwitchLb.switchTo(lbPolicies[2]);
verify(lb1).shutdown();
LoadBalancer lb2 = balancers.get(lbPolicies[2]);
verify(lb0, never()).shutdown();
helpers.get(lb2).updateBalancingState(READY, mock(SubchannelPicker.class));
verify(lb0).shutdown();
gracefulSwitchLb.switchTo(lbPolicies[3]);
LoadBalancer lb3 = balancers.get(lbPolicies[3]);
verify(lb2, never()).shutdown();
verify(lb3, never()).shutdown();
gracefulSwitchLb.shutdown();
verify(lb2).shutdown();
verify(lb3).shutdown();
verifyNoMoreInteractions(lb0, lb1, lb2, lb3);
}
@Test
@Deprecated
public void switchTo_requestConnectionForwardedToLatestPolicies() {
gracefulSwitchLb.switchTo(lbPolicies[0]);
LoadBalancer lb0 = balancers.get(lbPolicies[0]);
Helper helper0 = helpers.get(lb0);
SubchannelPicker picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(READY, picker);
gracefulSwitchLb.requestConnection();
verify(lb0).requestConnection();
gracefulSwitchLb.switchTo(lbPolicies[1]);
LoadBalancer lb1 = balancers.get(lbPolicies[1]);
gracefulSwitchLb.requestConnection();
verify(lb1).requestConnection();
gracefulSwitchLb.switchTo(lbPolicies[2]);
verify(lb1).shutdown();
LoadBalancer lb2 = balancers.get(lbPolicies[2]);
gracefulSwitchLb.requestConnection();
verify(lb2).requestConnection();
// lb2 reports READY
helpers.get(lb2).updateBalancingState(READY, mock(SubchannelPicker.class));
verify(lb0).shutdown();
gracefulSwitchLb.requestConnection();
verify(lb2, times(2)).requestConnection();
gracefulSwitchLb.switchTo(lbPolicies[3]);
LoadBalancer lb3 = balancers.get(lbPolicies[3]);
gracefulSwitchLb.requestConnection();
verify(lb3).requestConnection();
verifyNoMoreInteractions(lb0, lb1, lb2, lb3);
}
@Test
@Deprecated
public void switchTo_createSubchannelForwarded() {
gracefulSwitchLb.switchTo(lbPolicies[0]);
LoadBalancer lb0 = balancers.get(lbPolicies[0]);
Helper helper0 = helpers.get(lb0);
SubchannelPicker picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(READY, picker);
CreateSubchannelArgs createSubchannelArgs = newFakeCreateSubchannelArgs();
helper0.createSubchannel(createSubchannelArgs);
verify(mockHelper).createSubchannel(createSubchannelArgs);
gracefulSwitchLb.switchTo(lbPolicies[1]);
LoadBalancer lb1 = balancers.get(lbPolicies[1]);
Helper helper1 = helpers.get(lb1);
createSubchannelArgs = newFakeCreateSubchannelArgs();
helper1.createSubchannel(createSubchannelArgs);
verify(mockHelper).createSubchannel(createSubchannelArgs);
createSubchannelArgs = newFakeCreateSubchannelArgs();
helper0.createSubchannel(createSubchannelArgs);
verify(mockHelper).createSubchannel(createSubchannelArgs);
verifyNoMoreInteractions(lb0, lb1);
}
@Test
@Deprecated
public void switchTo_updateBalancingStateIsGraceful() {
gracefulSwitchLb.switchTo(lbPolicies[0]);
LoadBalancer lb0 = balancers.get(lbPolicies[0]);
Helper helper0 = helpers.get(lb0);
SubchannelPicker picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(READY, picker);
verify(mockHelper).updateBalancingState(READY, picker);
gracefulSwitchLb.switchTo(lbPolicies[1]);
LoadBalancer lb1 = balancers.get(lbPolicies[1]);
Helper helper1 = helpers.get(lb1);
picker = mock(SubchannelPicker.class);
helper1.updateBalancingState(CONNECTING, picker);
verify(mockHelper, never()).updateBalancingState(CONNECTING, picker);
gracefulSwitchLb.switchTo(lbPolicies[2]);
verify(lb1).shutdown();
LoadBalancer lb2 = balancers.get(lbPolicies[2]);
Helper helper2 = helpers.get(lb2);
picker = mock(SubchannelPicker.class);
helper2.updateBalancingState(CONNECTING, picker);
verify(mockHelper, never()).updateBalancingState(CONNECTING, picker);
// lb2 reports READY
SubchannelPicker picker2 = mock(SubchannelPicker.class);
helper2.updateBalancingState(READY, picker2);
verify(lb0).shutdown();
verify(mockHelper).updateBalancingState(READY, picker2);
gracefulSwitchLb.switchTo(lbPolicies[3]);
LoadBalancer lb3 = balancers.get(lbPolicies[3]);
Helper helper3 = helpers.get(lb3);
SubchannelPicker picker3 = mock(SubchannelPicker.class);
helper3.updateBalancingState(CONNECTING, picker3);
verify(mockHelper, never()).updateBalancingState(CONNECTING, picker3);
// lb2 out of READY
picker2 = mock(SubchannelPicker.class);
helper2.updateBalancingState(CONNECTING, picker2);
verify(mockHelper, never()).updateBalancingState(CONNECTING, picker2);
verify(mockHelper).updateBalancingState(CONNECTING, picker3);
verify(lb2).shutdown();
picker3 = mock(SubchannelPicker.class);
helper3.updateBalancingState(CONNECTING, picker3);
verify(mockHelper).updateBalancingState(CONNECTING, picker3);
verifyNoMoreInteractions(lb0, lb1, lb2, lb3);
}
@Test
@Deprecated
public void switchTo_switchWhileOldPolicyIsNotReady() {
gracefulSwitchLb.switchTo(lbPolicies[0]);
LoadBalancer lb0 = balancers.get(lbPolicies[0]);
Helper helper0 = helpers.get(lb0);
SubchannelPicker picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(READY, picker);
picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(CONNECTING, picker);
verify(lb0, never()).shutdown();
gracefulSwitchLb.switchTo(lbPolicies[1]);
verify(lb0).shutdown();
LoadBalancer lb1 = balancers.get(lbPolicies[1]);
Helper helper1 = helpers.get(lb1);
picker = mock(SubchannelPicker.class);
helper1.updateBalancingState(CONNECTING, picker);
verify(mockHelper).updateBalancingState(CONNECTING, picker);
verify(lb1, never()).shutdown();
gracefulSwitchLb.switchTo(lbPolicies[2]);
verify(lb1).shutdown();
LoadBalancer lb2 = balancers.get(lbPolicies[2]);
verifyNoMoreInteractions(lb0, lb1, lb2);
}
@Test
@Deprecated
public void switchTo_switchWhileOldPolicyGoesFromReadyToNotReady() {
gracefulSwitchLb.switchTo(lbPolicies[0]);
LoadBalancer lb0 = balancers.get(lbPolicies[0]);
Helper helper0 = helpers.get(lb0);
SubchannelPicker picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(READY, picker);
gracefulSwitchLb.switchTo(lbPolicies[1]);
verify(lb0, never()).shutdown();
LoadBalancer lb1 = balancers.get(lbPolicies[1]);
Helper helper1 = helpers.get(lb1);
SubchannelPicker picker1 = mock(SubchannelPicker.class);
helper1.updateBalancingState(CONNECTING, picker1);
verify(mockHelper, never()).updateBalancingState(CONNECTING, picker1);
picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(CONNECTING, picker);
verify(lb0).shutdown();
verify(mockHelper, never()).updateBalancingState(CONNECTING, picker);
verify(mockHelper).updateBalancingState(CONNECTING, picker1);
picker1 = mock(SubchannelPicker.class);
helper1.updateBalancingState(READY, picker1);
verify(mockHelper).updateBalancingState(READY, picker1);
verifyNoMoreInteractions(lb0, lb1);
}
@Test
@Deprecated
public void switchTo_switchWhileOldPolicyGoesFromReadyToNotReadyWhileNewPolicyStillIdle() {
gracefulSwitchLb.switchTo(lbPolicies[0]);
LoadBalancer lb0 = balancers.get(lbPolicies[0]);
InOrder inOrder = inOrder(lb0, mockHelper);
Helper helper0 = helpers.get(lb0);
SubchannelPicker picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(READY, picker);
gracefulSwitchLb.switchTo(lbPolicies[1]);
verify(lb0, never()).shutdown();
LoadBalancer lb1 = balancers.get(lbPolicies[1]);
Helper helper1 = helpers.get(lb1);
picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(CONNECTING, picker);
verify(mockHelper, never()).updateBalancingState(CONNECTING, picker);
inOrder.verify(mockHelper).updateBalancingState(CONNECTING, BUFFER_PICKER);
inOrder.verify(lb0).shutdown(); // shutdown after update
picker = mock(SubchannelPicker.class);
helper1.updateBalancingState(CONNECTING, picker);
inOrder.verify(mockHelper).updateBalancingState(CONNECTING, picker);
inOrder.verifyNoMoreInteractions();
verifyNoMoreInteractions(lb1);
}
@Test
@Deprecated
public void switchTo_newPolicyNameTheSameAsPendingPolicy_shouldHaveNoEffect() {
gracefulSwitchLb.switchTo(lbPolicies[0]);
LoadBalancer lb0 = balancers.get(lbPolicies[0]);
Helper helper0 = helpers.get(lb0);
SubchannelPicker picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(READY, picker);
gracefulSwitchLb.switchTo(lbPolicies[1]);
LoadBalancer lb1 = balancers.get(lbPolicies[1]);
gracefulSwitchLb.switchTo(lbPolicies[1]);
assertThat(balancers.get(lbPolicies[1])).isSameInstanceAs(lb1);
verifyNoMoreInteractions(lb0, lb1);
}
@Test
@Deprecated
public void switchTo_newPolicyNameTheSameAsCurrentPolicy_shouldShutdownPendingLb() {
gracefulSwitchLb.switchTo(lbPolicies[0]);
LoadBalancer lb0 = balancers.get(lbPolicies[0]);
gracefulSwitchLb.switchTo(lbPolicies[0]);
assertThat(balancers.get(lbPolicies[0])).isSameInstanceAs(lb0);
Helper helper0 = helpers.get(lb0);
SubchannelPicker picker = mock(SubchannelPicker.class);
helper0.updateBalancingState(READY, picker);
gracefulSwitchLb.switchTo(lbPolicies[1]);
LoadBalancer lb1 = balancers.get(lbPolicies[1]);
gracefulSwitchLb.switchTo(lbPolicies[0]);
verify(lb1).shutdown();
assertThat(balancers.get(lbPolicies[0])).isSameInstanceAs(lb0);
verifyNoMoreInteractions(lb0, lb1);
}
@Test
@Deprecated
public void switchTo_newLbFactoryEqualToOldOneShouldHaveNoEffect() {
final List<LoadBalancer> balancers = new ArrayList<>();
final class LoadBalancerFactoryWithId extends LoadBalancer.Factory {
final int id;
LoadBalancerFactoryWithId(int id) {
this.id = id;
}
@Override
public LoadBalancer newLoadBalancer(Helper helper) {
LoadBalancer balancer = mock(LoadBalancer.class);
balancers.add(balancer);
return balancer;
}
@Override
public boolean equals(Object o) {
if (!(o instanceof LoadBalancerFactoryWithId)) {
return false;
}
LoadBalancerFactoryWithId that = (LoadBalancerFactoryWithId) o;
return id == that.id;
}
@Override
public int hashCode() {
return id;
}
}
gracefulSwitchLb.switchTo(new LoadBalancerFactoryWithId(0));
assertThat(balancers).hasSize(1);
LoadBalancer lb0 = balancers.get(0);
gracefulSwitchLb.switchTo(new LoadBalancerFactoryWithId(0));
assertThat(balancers).hasSize(1);
gracefulSwitchLb.switchTo(new LoadBalancerFactoryWithId(1));
assertThat(balancers).hasSize(2);
LoadBalancer lb1 = balancers.get(1);
verify(lb0).shutdown();
verifyNoMoreInteractions(lb0, lb1);
}
// END OF OLD TESTS
@Test
public void transientFailureOnInitialResolutionError() {
gracefulSwitchLb.handleNameResolutionError(Status.DATA_LOSS);