Victor Xu created HBASE-10882:
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Summary: 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
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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