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Flume, mail # user - At flume shutdown only one HDFSSink is closed properly


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Bhaskar V. Karambelkar 2012-08-23, 22:24
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Mike Percy 2012-08-24, 01:35
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Re: At flume shutdown only one HDFSSink is closed properly
Bhaskar V. Karambelkar 2012-08-24, 19:13
oops, this is just the same Hadoop's FileSystem.close() shutdown hook
issue. I was getting the exception no matter whether I had 1 HDFS sink or
more.
I was using hadoop vanilla 1.0.3, and looks like that one doesn't respect
the fs.automatic.close option.
Switched to CDH3u5, and no more problems, all the HDFS sinks correctly
rename the file on shutdown.

In conclusion, the vanilla hadoop 1.x series is not an option for flume.

Go with Hadoop 2.x or CDH3u5, CDH4

thanks
Bhaskar

On Thu, Aug 23, 2012 at 9:35 PM, Mike Percy <[EMAIL PROTECTED]> wrote:

> Hmm... this likely happens because Hadoop statically caches the FileSystem
> object, so as it turns out, the multiple Sinks are sharing the same
> FileSystem objects.
>
> I think the only reason we need to explicitly close the FileSystem objects
> is to support the deleteOnExit feature. We are explicitly closing them
> because we removed the automatic shutdown hook typically installed by
> Hadoop to invoke FileSystem.close(), since it was interfering with the .tmp
> rolling. I wonder if we can get away with never closing them in our
> case... I'm not sure if we need the deleteOnExit() functionality implicitly
> for any reason, or if there are other more important reasons behind why the
> FileSystem objects should be closed.
>
> Regards,
> Mike
>
>
> On Thu, Aug 23, 2012 at 3:24 PM, Bhaskar V. Karambelkar <
> [EMAIL PROTECTED]> wrote:
>
>> I have 3 HDFS sinks all writing to the same namenode, but different paths.
>>
>> e.g. sink1 = hdfs://namenode/path1
>> sink2 = hdfs://namenode/path2
>> etc.
>>
>> When flume is shutdown (kill <flume-pid>), the file for the first sink is
>> closed correctly and renamed to remove the .tmp extension
>> but the second file's closing throws the following exception and the
>> file's .tmp extension is also not removed.
>> I see this happening very consistently, for 1+ HDFS sinks, only the first
>> one is closed properly and renamed, the rest all throw exception
>> when being closed, and are not renamed to remove the .tmp extension.
>>
>> 2012-08-23 19:51:39,837 WARN hdfs.BucketWriter: failed to close()
>> HDFSWriter for file
>> (hdfs://hadoop-namnode:9000/flume/avro/2012/08/23/l/avro_.1345751470750.tmp).
>> Exception follows.
>> java.io.IOException: Filesystem closed
>>     at org.apache.hadoop.hdfs.DFSClient.checkOpen(DFSClient.java:264)
>>     at org.apache.hadoop.hdfs.DFSClient.access$1100(DFSClient.java:74)
>>     at
>> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.sync(DFSClient.java:3667)
>>     at
>> org.apache.hadoop.fs.FSDataOutputStream.sync(FSDataOutputStream.java:97)
>>     at
>> org.apache.flume.sink.hdfs.HDFSDataStream.close(HDFSDataStream.java:103)
>>     at
>> org.apache.flume.sink.hdfs.BucketWriter.doClose(BucketWriter.java:250)
>>     at
>> org.apache.flume.sink.hdfs.BucketWriter.access$400(BucketWriter.java:48)
>>     at
>> org.apache.flume.sink.hdfs.BucketWriter$3.run(BucketWriter.java:236)
>>     at
>> org.apache.flume.sink.hdfs.BucketWriter$3.run(BucketWriter.java:233)
>>     at
>> org.apache.flume.sink.hdfs.BucketWriter.runPrivileged(BucketWriter.java:125)
>>     at
>> org.apache.flume.sink.hdfs.BucketWriter.close(BucketWriter.java:233)
>>     at
>> org.apache.flume.sink.hdfs.HDFSEventSink$3.call(HDFSEventSink.java:747)
>>     at
>> org.apache.flume.sink.hdfs.HDFSEventSink$3.call(HDFSEventSink.java:744)
>>     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
>>     at java.util.concurrent.FutureTask.run(FutureTask.java:138)
>>     at
>> java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
>>     at
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
>>     at java.lang.Thread.run(Thread.java:662)
>> 2012-08-23 19:51:39,840 WARN hdfs.HDFSEventSink: Exception while closing
>> hdfs://hadoop-namenode:9000/flume/avro/2012/08/23/avro_. Exception follows.
>> java.io.IOException: Filesystem closed
>>     at org.apache.hadoop.hdfs.DFSClient.checkOpen(DFSClient.java:264)
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Mike Percy 2012-08-24, 19:40
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Bhaskar V. Karambelkar 2012-08-27, 14:53
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Mike Percy 2012-08-29, 08:30