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Accumulo, mail # user - Using Accumulo as input to a MapReduce job frequently hangs due to lost Zookeeper connection


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Arjumand Bonhomme 2012-08-16, 07:59
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Jim Klucar 2012-08-16, 11:22
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Adam Fuchs 2012-08-16, 13:32
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Re: Using Accumulo as input to a MapReduce job frequently hangs due to lost Zookeeper connection
William Slacum 2012-08-16, 11:24
What does your TServer debug log say? Also, are you writing back out to
Accumulo?

To follow up what Jim said, you can check the zookeeper log to see if max
connections is being hit. You may also want to check and see what your max
xceivers is set to for HDFS and check your Accumulo and HDFS logs to see if
it is mentioned.

On Thu, Aug 16, 2012 at 3:59 AM, Arjumand Bonhomme <[EMAIL PROTECTED]> wrote:

> Hello,
>
> I'm fairly new to both Accumulo and Hadoop, so I think my problem may be
> due to poor configuration on my part, but I'm running out of ideas.
>
> I'm running this on a mac laptop, with hadoop (hadoop-0.20.2 from cdh3u4)
> in pseudo-distributed mode.
> zookeeper version zookeeper-3.3.5 from cdh3u4
> I'm using the 1.4.1 release of accumulo with a configuration copied from
> "conf/examples/512MB/standalone"
>
> I've got a Map task that is using an accumulo table as the input.
> I'm fetching all rows, but just a single column family, that has hundreds
> or even thousands of different column qualifiers.
> The table has a SummingCombiner installed for the given the column family.
>
> The task runs fine at first, but after ~9-15K records (I print the record
> count to the console every 1K records), it hangs and the following messages
> are printed to the console where I'm running the job:
> 12/08/16 02:57:08 INFO zookeeper.ClientCnxn: Unable to read additional
> data from server sessionid 0x1392cc35b460d1c, likely server has closed
> socket, closing socket connection and attempting reconnect
> 12/08/16 02:57:08 INFO zookeeper.ClientCnxn: Opening socket connection to
> server localhost/fe80:0:0:0:0:0:0:1%1:2181
> 12/08/16 02:57:08 INFO zookeeper.ClientCnxn: Socket connection established
> to localhost/fe80:0:0:0:0:0:0:1%1:2181, initiating session
> 12/08/16 02:57:08 INFO zookeeper.ClientCnxn: Unable to reconnect to
> ZooKeeper service, session 0x1392cc35b460d1c has expired, closing socket
> connection
> 12/08/16 02:57:08 INFO zookeeper.ClientCnxn: EventThread shut down
> 12/08/16 02:57:10 INFO zookeeper.ZooKeeper: Initiating client connection,
> connectString=localhost sessionTimeout=30000
> watcher=org.apache.accumulo.core.zookeeper.ZooSession$AccumuloWatcher@32f5c51c
> 12/08/16 02:57:10 INFO zookeeper.ClientCnxn: Opening socket connection to
> server localhost/0:0:0:0:0:0:0:1:2181
> 12/08/16 02:57:10 INFO zookeeper.ClientCnxn: Socket connection established
> to localhost/0:0:0:0:0:0:0:1:2181, initiating session
> 12/08/16 02:57:10 INFO zookeeper.ClientCnxn: Session establishment
> complete on server localhost/0:0:0:0:0:0:0:1:2181, sessionid > 0x1392cc35b460d25, negotiated timeout = 30000
> 12/08/16 02:57:11 INFO mapred.LocalJobRunner:
> 12/08/16 02:57:14 INFO mapred.LocalJobRunner:
> 12/08/16 02:57:17 INFO mapred.LocalJobRunner:
>
> Sometimes the messages contain a stacktrace like this below:
> 12/08/16 01:57:40 WARN zookeeper.ClientCnxn: Session 0x1392cc35b460b40 for
> server localhost/fe80:0:0:0:0:0:0:1%1:2181, unexpected error, closing
> socket connection and attempting reconnect
> java.io.IOException: Connection reset by peer
>  at sun.nio.ch.FileDispatcher.read0(Native Method)
> at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:21)
>  at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:198)
> at sun.nio.ch.IOUtil.read(IOUtil.java:166)
>  at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:245)
> at org.apache.zookeeper.ClientCnxn$SendThread.doIO(ClientCnxn.java:856)
>  at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1154)
> 12/08/16 01:57:40 INFO zookeeper.ClientCnxn: Opening socket connection to
> server localhost/127.0.0.1:2181
> 12/08/16 01:57:40 INFO zookeeper.ClientCnxn: Socket connection established
> to localhost/127.0.0.1:2181, initiating session
> 12/08/16 01:57:40 INFO zookeeper.ClientCnxn: Unable to reconnect to
> ZooKeeper service, session 0x1392cc35b460b40 has expired, closing socket
> connection
> 12/08/16 01:57:40 INFO zookeeper.ClientCnxn: EventThread shut down
> 12/08/16 01:57:41 INFO zookeeper.ZooKeeper: Initiating client connection,
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Arjumand Bonhomme 2012-08-16, 18:36
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John Vines 2012-08-16, 19:24
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Arjumand Bonhomme 2012-08-16, 19:48
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Arjumand Bonhomme 2012-08-17, 02:10
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Arjumand Bonhomme 2012-08-20, 17:00
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Keith Turner 2012-08-20, 17:34
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David Medinets 2012-08-21, 00:26
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Keith Turner 2012-08-21, 12:23
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ameet kini 2012-10-10, 14:22
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Billie Rinaldi 2012-10-11, 18:57
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ameet kini 2012-10-17, 14:10
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ameet kini 2012-10-17, 14:13
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David Medinets 2012-08-17, 02:33
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Arjumand Bonhomme 2012-08-17, 03:14