[FLUME-3054] hflushOrSync method in HDFS Sink should not treat ClosedChannelException as an error

• Type: Bug
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.6.0
• Component/s: Sinks+Sources
• Assignee: Unassigned
• Reporter: Pan Yuxuan
• Created: 10/Feb/17 10:01
• Updated: 01/Jun/22 15:24

Description

When use HDFS Sink in multiple threads, we face the error in log as below:

09 Feb 2017 13:44:14,721 ERROR [hdfs-hsProt6-call-runner-4] (org.apache.flume.sink.hdfs.AbstractHDFSWriter.hflushOrSync:267)  - Error while trying to hflushOrSync!
09 Feb 2017 14:54:48,271 ERROR [SinkRunner-PollingRunner-DefaultSinkProcessor] (org.apache.flume.sink.hdfs.AbstractHDFSWriter.isUnderReplicated:98)  - Unexpected error while checking replication factor
java.lang.reflect.InvocationTargetException
	at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.flume.sink.hdfs.AbstractHDFSWriter.getNumCurrentReplicas(AbstractHDFSWriter.java:165)
	at org.apache.flume.sink.hdfs.AbstractHDFSWriter.isUnderReplicated(AbstractHDFSWriter.java:84)
	at org.apache.flume.sink.hdfs.BucketWriter.shouldRotate(BucketWriter.java:583)
	at org.apache.flume.sink.hdfs.BucketWriter.append(BucketWriter.java:518)
	at org.apache.flume.sink.hdfs.HDFSEventSink.process(HDFSEventSink.java:418)
	at org.apache.flume.sink.DefaultSinkProcessor.process(DefaultSinkProcessor.java:68)
	at org.apache.flume.SinkRunner$PollingRunner.run(SinkRunner.java:147)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.nio.channels.ClosedChannelException
	at org.apache.hadoop.hdfs.DFSOutputStream.checkClosed(DFSOutputStream.java:1665)
	at org.apache.hadoop.hdfs.DFSOutputStream.getCurrentBlockReplication(DFSOutputStream.java:2151)
	at org.apache.hadoop.hdfs.DFSOutputStream.getNumCurrentReplicas(DFSOutputStream.java:2140)
	... 11 more
09 Feb 2017 14:54:48,277 ERROR [SinkRunner-PollingRunner-DefaultSinkProcessor] (org.apache.flume.sink.hdfs.HDFSEventSink.process:459)  - process failed
org.apache.flume.auth.SecurityException: Privileged action failed
	at org.apache.flume.auth.UGIExecutor.execute(UGIExecutor.java:49)
	at org.apache.flume.auth.KerberosAuthenticator.execute(KerberosAuthenticator.java:63)
	at org.apache.flume.sink.hdfs.BucketWriter$9.call(BucketWriter.java:676)
	at java.util.concurrent.FutureTask.run(FutureTask.java:262)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.nio.channels.ClosedChannelException
	at org.apache.hadoop.hdfs.DFSOutputStream.checkClosed(DFSOutputStream.java:1665)
	at org.apache.hadoop.fs.FSOutputSummer.write(FSOutputSummer.java:104)
	at org.apache.hadoop.fs.FSDataOutputStream$PositionCache.write(FSDataOutputStream.java:58)
	at java.io.DataOutputStream.write(DataOutputStream.java:107)
	at java.io.FilterOutputStream.write(FilterOutputStream.java:97)
	at org.apache.flume.serialization.BodyTextEventSerializer.write(BodyTextEventSerializer.java:71)
	at org.apache.flume.sink.hdfs.HDFSDataStream.append(HDFSDataStream.java:124)
	at org.apache.flume.sink.hdfs.BucketWriter$7.call(BucketWriter.java:550)
	at org.apache.flume.sink.hdfs.BucketWriter$7.call(BucketWriter.java:547)
	at org.apache.flume.sink.hdfs.BucketWriter$9$1.run(BucketWriter.java:679)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:415)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1858)
	at org.apache.flume.auth.UGIExecutor.execute(UGIExecutor.java:47)
	... 6 more
09 Feb 2017 14:54:48,280 ERROR [SinkRunner-PollingRunner-DefaultSinkProcessor] (org.apache.flume.SinkRunner$PollingRunner.run:160)  - Unable to deliver event. Exception follows.
org.apache.flume.EventDeliveryException: org.apache.flume.auth.SecurityException: Privileged action failed
	at org.apache.flume.sink.hdfs.HDFSEventSink.process(HDFSEventSink.java:463)
	at org.apache.flume.sink.DefaultSinkProcessor.process(DefaultSinkProcessor.java:68)
	at org.apache.flume.SinkRunner$PollingRunner.run(SinkRunner.java:147)
	at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.flume.auth.SecurityException: Privileged action failed
	at org.apache.flume.auth.UGIExecutor.execute(UGIExecutor.java:49)
	at org.apache.flume.auth.KerberosAuthenticator.execute(KerberosAuthenticator.java:63)
	at org.apache.flume.sink.hdfs.BucketWriter$9.call(BucketWriter.java:676)
	at java.util.concurrent.FutureTask.run(FutureTask.java:262)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	... 1 more
Caused by: java.nio.channels.ClosedChannelException
	at org.apache.hadoop.hdfs.DFSOutputStream.checkClosed(DFSOutputStream.java:1665)
	at org.apache.hadoop.fs.FSOutputSummer.write(FSOutputSummer.java:104)
	at org.apache.hadoop.fs.FSDataOutputStream$PositionCache.write(FSDataOutputStream.java:58)
	at java.io.DataOutputStream.write(DataOutputStream.java:107)
	at java.io.FilterOutputStream.write(FilterOutputStream.java:97)
	at org.apache.flume.serialization.BodyTextEventSerializer.write(BodyTextEventSerializer.java:71)
	at org.apache.flume.sink.hdfs.HDFSDataStream.append(HDFSDataStream.java:124)
	at org.apache.flume.sink.hdfs.BucketWriter$7.call(BucketWriter.java:550)
	at org.apache.flume.sink.hdfs.BucketWriter$7.call(BucketWriter.java:547)
	at org.apache.flume.sink.hdfs.BucketWriter$9$1.run(BucketWriter.java:679)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:415)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1858)
	at org.apache.flume.auth.UGIExecutor.execute(UGIExecutor.java:47)
	... 6 more

The error shows that when call hflushOrSync(), the DataOutputStream was closed by other threads, so DataOutputStream throws ClosedChannelException. But the hdfs sink was not affected by the exception, DataOutputStream just throws the ClosedChannelException as a remind. So we should ignore the ClosedChannelException instead by logging as an error.