[BEAM-2170] PubsubIO.readStrings should handle messages without metadata

• Type: Bug
• Status: Resolved
• Priority: P2
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Component/s: io-java-gcp
• Flags: Important
• Assignee: Eugene Kirpichov
• Reporter: Alexandre Crayssac
• Created: 04/May/17 13:14
• Updated: 24/Jul/20 20:20
• Resolved: 04/May/17 23:26

Description

When I use PubsubIO.readStrings with messages that does not contain any metadata I got the following error:

java.lang.reflect.InvocationTargetException
	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.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:293)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.RuntimeException: org.apache.beam.sdk.coders.CoderException: cannot encode a null Map
	at org.apache.beam.runners.direct.ImmutabilityCheckingBundleFactory$ImmutabilityEnforcingBundle.add(ImmutabilityCheckingBundleFactory.java:113)
	at org.apache.beam.runners.direct.UnboundedReadEvaluatorFactory$UnboundedReadEvaluator.processElement(UnboundedReadEvaluatorFactory.java:134)
	at org.apache.beam.runners.direct.TransformExecutor.processElements(TransformExecutor.java:138)
	at org.apache.beam.runners.direct.TransformExecutor.run(TransformExecutor.java:106)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	... 1 more
Caused by: org.apache.beam.sdk.coders.CoderException: cannot encode a null Map
	at org.apache.beam.sdk.coders.MapCoder.encode(MapCoder.java:90)
	at org.apache.beam.sdk.coders.MapCoder.encode(MapCoder.java:43)
	at org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageWithAttributesCoder.encode(PubsubMessageWithAttributesCoder.java:53)
	at org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageWithAttributesCoder.encode(PubsubMessageWithAttributesCoder.java:33)
	at org.apache.beam.sdk.util.CoderUtils.encodeToSafeStream(CoderUtils.java:91)
	at org.apache.beam.sdk.util.CoderUtils.encodeToByteArray(CoderUtils.java:75)
	at org.apache.beam.sdk.util.CoderUtils.encodeToByteArray(CoderUtils.java:60)
	at org.apache.beam.sdk.util.MutationDetectors$CodedValueMutationDetector.<init>(MutationDetectors.java:106)
	at org.apache.beam.sdk.util.MutationDetectors.forValueWithCoder(MutationDetectors.java:44)
	at org.apache.beam.runners.direct.ImmutabilityCheckingBundleFactory$ImmutabilityEnforcingBundle.add(ImmutabilityCheckingBundleFactory.java:111)
	... 8 more

When I add some metadata the problem disappears. You should be able to reproduce the problem with a very simple pipeline consisting of only one PubsubIO.readStrings.

Tell me if you need more information

Issue Links

• links to: GitHub Pull Request #2900