[BEAM-257] fix ConcurrentModificationException in KafkaIO

• Type: Bug
• Status: Resolved
• Priority: P2
• Resolution: Fixed
• Fix Version/s: 0.1.0-incubating
• Component/s: io-java-kafka
• Assignee: Raghu Angadi
• Reporter: Raghu Angadi
• Created: 05/May/16 01:42
• Updated: 24/Jul/20 20:55
• Resolved: 13/Oct/16 16:53

Description

tgroh reported the following exception with KafkaIO while using with DirectRunner. Fixing it in https://github.com/apache/incubator-beam/pull/290

 java.util.ConcurrentModificationException: KafkaConsumer is not safe for multi-threaded access
	at org.apache.kafka.clients.consumer.KafkaConsumer.acquire(KafkaConsumer.java:1324)
	at org.apache.kafka.clients.consumer.KafkaConsumer.close(KafkaConsumer.java:1255)
	at com.google.common.io.Closeables.close(Closeables.java:79)
	at org.apache.beam.sdk.io.kafka.KafkaIO$UnboundedKafkaReader.close(KafkaIO.java:1050)
	at org.apache.beam.runners.direct.UnboundedReadEvaluatorFactory$UnboundedReadEvaluator.finishBundle(UnboundedReadEvaluatorFactory.java:167)
	at org.apache.beam.runners.direct.TransformExecutor.finishBundle(TransformExecutor.java:161)
	at org.apache.beam.runners.direct.TransformExecutor.call(TransformExecutor.java:116)
	at org.apache.beam.runners.direct.TransformExecutor.call(TransformExecutor.java:41)
	at java.util.concurrent.FutureTask.run(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)