bigtable.hbase.async.TestAsyncSnapshots: testListAndDeleteSnapshots failed

Note: #3361 was also for this test, but it was closed more than 10 days ago. So, I didn't mark it flaky.

----

commit: 71e2db0b4443460838d7bd0b25ae18d669dc3230
buildURL: [Build Status](https://source.cloud.google.com/results/invocations/9d54fa98-ecb0-4683-892a-8d47f80d172c), [Sponge](http://sponge2/9d54fa98-ecb0-4683-892a-8d47f80d172c)
status: failed
Test output

com.google.cloud.bigtable.admin.v2.models.PartialListClustersException: Failed to list all clusters, some zones were unavailable: [europe-west9-b, europe-west9-c, europe-west9-a]

	at com.google.cloud.bigtable.admin.v2.BigtableInstanceAdminClient$9.apply(BigtableInstanceAdminClient.java:651)

	at com.google.cloud.bigtable.admin.v2.BigtableInstanceAdminClient$9.apply(BigtableInstanceAdminClient.java:630)

	at com.google.api.core.ApiFutures$ApiFunctionToGuavaFunction.apply(ApiFutures.java:397)

	at com.google.common.util.concurrent.AbstractTransformFuture$TransformFuture.doTransform(AbstractTransformFuture.java:250)

	at com.google.common.util.concurrent.AbstractTransformFuture$TransformFuture.doTransform(AbstractTransformFuture.java:240)

	at com.google.common.util.concurrent.AbstractTransformFuture.run(AbstractTransformFuture.java:122)

	at com.google.common.util.concurrent.DirectExecutor.execute(DirectExecutor.java:31)

	at com.google.common.util.concurrent.AbstractFuture.executeListener(AbstractFuture.java:1270)

	at com.google.common.util.concurrent.AbstractFuture.complete(AbstractFuture.java:1038)

	at com.google.common.util.concurrent.AbstractFuture.set(AbstractFuture.java:783)

	at com.google.api.gax.retrying.BasicRetryingFuture.handleAttempt(BasicRetryingFuture.java:203)

	at com.google.api.gax.retrying.CallbackChainRetryingFuture$AttemptCompletionListener.handle(CallbackChainRetryingFuture.java:135)

	at com.google.api.gax.retrying.CallbackChainRetryingFuture$AttemptCompletionListener.run(CallbackChainRetryingFuture.java:115)

	at com.google.common.util.concurrent.DirectExecutor.execute(DirectExecutor.java:31)

	at com.google.common.util.concurrent.AbstractFuture.executeListener(AbstractFuture.java:1270)

	at com.google.common.util.concurrent.AbstractFuture.complete(AbstractFuture.java:1038)

	at com.google.common.util.concurrent.AbstractFuture.set(AbstractFuture.java:783)

	at com.google.api.core.AbstractApiFuture$InternalSettableFuture.set(AbstractApiFuture.java:87)

	at com.google.api.core.AbstractApiFuture.set(AbstractApiFuture.java:70)

	at com.google.api.gax.grpc.GrpcExceptionCallable$ExceptionTransformingFuture.onSuccess(GrpcExceptionCallable.java:88)

	at com.google.api.core.ApiFutures$1.onSuccess(ApiFutures.java:89)

	at com.google.common.util.concurrent.Futures$CallbackListener.run(Futures.java:1138)

	at com.google.common.util.concurrent.DirectExecutor.execute(DirectExecutor.java:31)

	at com.google.common.util.concurrent.AbstractFuture.executeListener(AbstractFuture.java:1270)

	at com.google.common.util.concurrent.AbstractFuture.complete(AbstractFuture.java:1038)

	at com.google.common.util.concurrent.AbstractFuture.set(AbstractFuture.java:783)

	at io.grpc.stub.ClientCalls$GrpcFuture.set(ClientCalls.java:569)

	at io.grpc.stub.ClientCalls$UnaryStreamToFuture.onClose(ClientCalls.java:542)

	at io.grpc.PartialForwardingClientCallListener.onClose(PartialForwardingClientCallListener.java:39)

	at io.grpc.ForwardingClientCallListener.onClose(ForwardingClientCallListener.java:23)

	at io.grpc.ForwardingClientCallListener$SimpleForwardingClientCallListener.onClose(ForwardingClientCallListener.java:40)

	at com.google.api.gax.grpc.ChannelPool$ReleasingClientCall$1.onClose(ChannelPool.java:541)

	at io.grpc.internal.ClientCallImpl.closeObserver(ClientCallImpl.java:576)

	at io.grpc.internal.ClientCallImpl.access$300(ClientCallImpl.java:70)

	at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInternal(ClientCallImpl.java:757)

	at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInContext(ClientCallImpl.java:736)

	at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)

	at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:133)

	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)

	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)

	at java.lang.Thread.run(Thread.java:750)

	Suppressed: com.google.api.gax.rpc.AsyncTaskException: Asynchronous task failed

		at com.google.api.gax.rpc.ApiExceptions.callAndTranslateApiException(ApiExceptions.java:57)

		at com.google.cloud.bigtable.admin.v2.BigtableInstanceAdminClient.listClusters(BigtableInstanceAdminClient.java:591)

		at com.google.cloud.bigtable.hbase.wrappers.veneer.AdminClientVeneerApi.listClusters(AdminClientVeneerApi.java:107)

		at com.google.cloud.bigtable.hbase2_x.BigtableAsyncAdmin.getBackupClusterId(BigtableAsyncAdmin.java:517)

		at com.google.cloud.bigtable.hbase2_x.BigtableAsyncAdmin.deleteSnapshot(BigtableAsyncAdmin.java:330)

		at com.google.cloud.bigtable.hbase.async.TestAsyncSnapshots.deleteSnapshot(TestAsyncSnapshots.java:147)

		at com.google.cloud.bigtable.hbase.AbstractTestSnapshot.testListAndDeleteSnapshots(AbstractTestSnapshot.java:97)

		at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

		at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

		at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

		at java.lang.reflect.Method.invoke(Method.java:498)

		at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)

		at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)

		at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)

		at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)

		at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)

		at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)

		at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)

		at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)

		at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)

		at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)

		at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)

		at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)

		at org.apache.maven.surefire.junitcore.pc.Scheduler$1.run(Scheduler.java:345)

		at org.apache.maven.surefire.junitcore.pc.InvokerStrategy.schedule(InvokerStrategy.java:47)

		at org.apache.maven.surefire.junitcore.pc.Scheduler.schedule(Scheduler.java:316)

		at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)

		at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)

		at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)

		at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)

		at org.junit.runners.ParentRunner.run(ParentRunner.java:413)

		at org.junit.runners.Suite.runChild(Suite.java:128)

		at org.junit.runners.Suite.runChild(Suite.java:27)

		at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)

		at org.apache.maven.surefire.junitcore.pc.Scheduler$1.run(Scheduler.java:345)

		at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)

		at java.util.concurrent.FutureTask.run(FutureTask.java:266)

		... 3 more