[jira] [Resolved] (HBASE-10882) Bulkload process hangs on regions randomly and finally throws RegionTooBusyException

["Andrew Purtell (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HBASE-10882?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Andrew Purtell resolved HBASE-10882.
------------------------------------

    Resolution: Invalid

Please ask for assistance on the user@hbase.apache.org mailing list.

> Bulkload process hangs on regions randomly and finally throws RegionTooBusyException
> ------------------------------------------------------------------------------------
>
>                 Key: HBASE-10882
>                 URL: https://issues.apache.org/jira/browse/HBASE-10882
>             Project: HBase
>          Issue Type: Bug
>          Components: regionserver
>    Affects Versions: 0.94.10
>         Environment: rhel 5.6, jdk1.7.0_45, hadoop-2.2.0-cdh5.0.0
>            Reporter: Victor Xu
>         Attachments: jstack_5105.log
>
>
> I came across the problem in the early morning several days ago. It happened when I used hadoop completebulkload command to bulk load some hdfs files into hbase table. Several regions hung and after retried three times they all threw RegionTooBusyExceptions. Fortunately, I caught one of the exceptional region’s HRegionServer process’s jstack info just in time.
> I found that the bulkload process was waiting for a write lock:
> at java.util.concurrent.locks.ReentrantReadWriteLock$WriteLock.tryLock(ReentrantReadWriteLock.java:1115)
> The lock id is 0x00000004054ecbf0.
> In the meantime, many other Get/Scan operations were also waiting for the same lock id. And, of course, they were waiting for the read lock:
> at java.util.concurrent.locks.ReentrantReadWriteLock$ReadLock.tryLock(ReentrantReadWriteLock.java:873)
> The most ridiculous thing is NO ONE OWNED THE LOCK! I searched the jstack output carefully, but cannot find any process who claimed to own the lock.
> When I restart the bulk load process, it failed at different regions but with the same RegionTooBusyExceptions. 
> I guess maybe the region was doing some compactions at that time and owned the lock, but I couldn’t find compaction info in the hbase-logs.
> Finally, after several days’ hard work, the only temporary solution to this problem was found, that is TRIGGERING A MAJOR COMPACTION BEFORE THE BULKLOAD, 
> So which process owned the lock? Has anyone came across the same problem before?



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