bigtable.grpc.async.TestBulkRead: testMissingResponses failed

[flaky-bot]

This test failed!

To configure my behavior, see the Build Cop Bot documentation.

If I'm commenting on this issue too often, add the buildcop: quiet label and
I will stop commenting.

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commit: 6bff6e5
buildURL: Build Status, Sponge
status: failed

Test output

java.lang.AssertionError: expected null, but was:, cells=[Cell{family=family, qualifier=, timestamp=1606811037789, value=, labels=[]}]}>
	at org.junit.Assert.fail(Assert.java:89)
	at org.junit.Assert.failNotNull(Assert.java:756)
	at org.junit.Assert.assertNull(Assert.java:738)
	at org.junit.Assert.assertNull(Assert.java:748)
	at com.google.cloud.bigtable.grpc.async.TestBulkRead.testMissingResponses(TestBulkRead.java:168)
	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.mockito.internal.junit.JUnitSessionStore$1.evaluateSafely(JUnitSessionStore.java:54)
	at org.mockito.internal.junit.JUnitSessionStore$1.evaluate(JUnitSessionStore.java:42)
	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.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
	at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:365)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeWithRerun(JUnit4Provider.java:273)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:238)
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:159)
	at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:384)
	at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:345)
	at org.apache.maven.surefire.booter.ForkedBooter.execute(ForkedBooter.java:126)
	at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:418)

[flaky-bot]

Looks like this issue is flaky. 😟

I'm going to leave this open and stop commenting.

A human should fix and close this.

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When run at the same commit (6bff6e5), this test passed in one build (Build Status, Sponge) and failed in another build (Build Status, Sponge).

[dmitry-fa]

Such failure happens if the array of 100 random row keys contains two equal. The keys are generated as a random int from 0 to 100_000_000.
The probability of such an event is quite low, approximately 1/1_000_000, but if the test is run 1000 times the chance of failure will be better than 1 to 1000, which is quite possible.

Using a random generator with an unset seed in tests is not a good practice, because reproducing failures is next to impossible. Printing the seed for a pseudo-random generator or using the permanent seed will allow repeating the exact behavior.