Can you describe your zookeeper setup a little more ? Thanks
On Tue, May 29, 2012 at 6:52 PM, Ey-Chih chow <[email protected]> wrote: > Hi, > > We have some performance issue with a hbase map-only job, that copies data > from hbase to hdfs. We profiled the job and what follows were the top 6 > ranked methods, in terms of CPU usages, and the corresponding traces. > > ========================================================================== > > CPU SAMPLES BEGIN (total = 1162350) Tue May 29 16:54:18 2012 > rank self accum count trace method > 1 16.67% 16.67% 193724 312698 sun.nio.ch.EPollArrayWrapper.epollWait > 2 16.66% 33.32% 193609 314324 sun.nio.ch.EPollArrayWrapper.epollWait > 3 16.65% 49.98% 193573 314044 sun.nio.ch.EPollArrayWrapper.epollWait > 4 16.56% 66.54% 192491 319621 sun.nio.ch.EPollArrayWrapper.epollWait > 5 10.90% 77.44% 126699 319206 sun.nio.ch.EPollArrayWrapper.epollWait > 6 5.64% 83.08% 65565 327226 sun.nio.ch.EPollArrayWrapper.epollWait > > TRACE 312698: (thread=200010) > > sun.nio.ch.EPollArrayWrapper.epollWait(EPollArrayWrapper.java:Unknown line) > sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:210) > sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:65) > sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69) > sun.nio.ch.SelectorImpl.select(SelectorImpl.java:80) > org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1107) > > TRACE 314324: (thread=200015) > > sun.nio.ch.EPollArrayWrapper.epollWait(EPollArrayWrapper.java:Unknown line) > sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:210) > sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:65) > sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69) > sun.nio.ch.SelectorImpl.select(SelectorImpl.java:80) > org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1107) > > TRACE 314044: (thread=200013) > > sun.nio.ch.EPollArrayWrapper.epollWait(EPollArrayWrapper.java:Unknown line) > sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:210) > sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:65) > sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69) > sun.nio.ch.SelectorImpl.select(SelectorImpl.java:80) > org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1107) > > TRACE 319621: (thread=200023) > > sun.nio.ch.EPollArrayWrapper.epollWait(EPollArrayWrapper.java:Unknown line) > sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:210) > sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:65) > sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69) > sun.nio.ch.SelectorImpl.select(SelectorImpl.java:80) > org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1107) > > TRACE 319206: (thread=200022) > > sun.nio.ch.EPollArrayWrapper.epollWait(EPollArrayWrapper.java:Unknown line) > sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:210) > sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:65) > sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69) > sun.nio.ch.SelectorImpl.select(SelectorImpl.java:80) > > > org.apache.hadoop.net.SocketIOWithTimeout$SelectorPool.select(SocketIOWithTimeout.java:332) > > TRACE 327226: (thread=200101) > > sun.nio.ch.EPollArrayWrapper.epollWait(EPollArrayWrapper.java:Unknown line) > sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:210) > sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:65) > sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69) > sun.nio.ch.SelectorImpl.select(SelectorImpl.java:80) > > > org.apache.hadoop.net.SocketIOWithTimeout$SelectorPool.select(SocketIOWithTimeout.java:332) > > =============================================================== > > Looks like the problem may be related to Zookeeper connections. Is there > anybody knows how to improve the performance of the job? Thanks. > > Ey-Chih Chow
