Streaming Java WordCountIT.testE2EWordCount ambiguous failure

Test reports a failure, but the UI reports the job was successful. There are some steps in the pipeline that are confusing from a UX perspective as well (see attached screenshot of UI).

 
```

Error Messagejava.lang.RuntimeException: Error processing pipeline.Stacktracejava.lang.RuntimeException:
Error processing pipeline.
at org.apache.beam.runners.dataflow.TestDataflowRunner.run(TestDataflowRunner.java:137)
at
org.apache.beam.runners.dataflow.TestDataflowRunner.run(TestDataflowRunner.java:93)
at org.apache.beam.runners.dataflow.TestDataflowRunner.run(TestDataflowRunner.java:55)
at
org.apache.beam.sdk.Pipeline.run(Pipeline.java:322)
at org.apache.beam.sdk.Pipeline.run(Pipeline.java:308)
at
org.apache.beam.examples.WordCount.runWordCount(WordCount.java:185)
at org.apache.beam.examples.WordCountIT.testE2EWordCount(WordCountIT.java:69)
at
jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at
jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at
java.lang.reflect.Method.invoke(Method.java:566)
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.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.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
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.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at
org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
at
org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.runTestClass(JUnitTestClassExecutor.java:110)
at
org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:58)
at
org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:38)
at
org.gradle.api.internal.tasks.testing.junit.AbstractJUnitTestClassProcessor.processTestClass(AbstractJUnitTestClassProcessor.java:62)
at
org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:51)
at
jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at
jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at
java.lang.reflect.Method.invoke(Method.java:566)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
at
org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
at
org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
at
com.sun.proxy.$Proxy2.processTestClass(Unknown Source)
at org.gradle.api.internal.tasks.testing.worker.TestWorker.processTestClass(TestWorker.java:119)
at
jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at
jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at
java.lang.reflect.Method.invoke(Method.java:566)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
at
org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:182)
at
org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:164)
at
org.gradle.internal.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:414)
at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
at
org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
at
java.lang.Thread.run(Thread.java:834)
Standard ErrorJan 11, 2021 10:30:59 PM org.apache.beam.runners.dataflow.options.DataflowPipelineOptions$StagingLocationFactory
create
INFO: No stagingLocation provided, falling back to gcpTempLocation
Jan 11, 2021 10:31:00 PM
org.apache.beam.runners.dataflow.DataflowRunner fromOptions
INFO: PipelineOptions.filesToStage was
not specified. Defaulting to files from the classpath: will stage 188 files. Enable logging at DEBUG
level to see which files will be staged.
Jan 11, 2021 10:31:03 PM org.apache.beam.sdk.co
...[truncated
120905 chars]...
ache.beam.runners.dataflow.DataflowPipelineJob logTerminalState
INFO: Job 2021-01-11_14_31_10-9493314082335955186
finished with status DONE.
Jan 11, 2021 10:34:37 PM org.apache.beam.runners.dataflow.TestDataflowRunner
run
WARNING: Dataflow job 2021-01-11_14_31_10-9493314082335955186 did not output a success or failure
metric.
Jan 11, 2021 10:34:37 PM org.apache.beam.runners.dataflow.DataflowPipelineJob logTerminalState
INFO:
Job 2021-01-11_14_31_10-9493314082335955186 finished with status DONE.

```

!9ycLiPHesoLT6ym.png|width=1332,height=643!

Imported from Jira [BEAM-11621](https://issues.apache.org/jira/browse/BEAM-11621). Original Jira may contain additional context.
Reported by: tysonjh.