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https://issues.apache.org/jira/browse/HDFS-2243?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13089684#comment-13089684
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Todd Lipcon commented on HDFS-2243:
-----------------------------------

Great. Feel free to ping me on IRC (tlipcon in #hadoop or #hbase) if you have 
any issues getting it up and running.

> DataXceiver per accept seems to be a bottleneck in HBase/YCSB test
> ------------------------------------------------------------------
>
>                 Key: HDFS-2243
>                 URL: https://issues.apache.org/jira/browse/HDFS-2243
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: data-node
>    Affects Versions: 0.23.0
>         Environment: Using Fedora 14 on a quad core phenom system
>            Reporter: Eric Caspole
>            Priority: Minor
>         Attachments: HDFS-2234-branch-0.20-append.patch, 
> datanode-perf-110808.gif
>
>
> I am running the YCSB benchmark against HBase, sometimes against a single 
> node, sometimes against a cluster of 6 systems. As the load increases into 
> thousands of TPS, especially on the single node, I can see that the datanode 
> runs very high system time and seems to be bottlenecked by how fast it can 
> create the threads to handle the new connections in DataXceiverServer.run. By 
> "perf top" I can see the process spends about 12% of all its time in 
> pthread_create, and in hprof profiles I can see there are tens of thousands 
> of threads created in just a few minutes of test execution.
> Does anyone else observe this bottleneck? Is there a major challenge to using 
> a thread pool of DataXceivers in this situation?

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