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https://issues.apache.org/jira/browse/HBASE-21428?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16689035#comment-16689035
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Reid Chan commented on HBASE-21428:
-----------------------------------
ping [~carp84], what do you think about this performance issue, would you mind
taking a look?
> Performance issue due to userRegionLock in the ConnectionManager.
> -----------------------------------------------------------------
>
> Key: HBASE-21428
> URL: https://issues.apache.org/jira/browse/HBASE-21428
> Project: HBase
> Issue Type: Bug
> Affects Versions: 1.2.7
> Reporter: koo
> Priority: Major
>
> My service is that execute a lot of puts using HTableMultiplexer.
> After the version change, most of the requests are rejected.
> It works fine in 1.2.6.1, but there is a problem in 1.2.7.
> This issue is related with the HBASE-19260.
> Most of my threads are using a lot of time as below.
>
> |"Worker-972" #2479 daemon prio=5 os_prio=0 tid=0x00007f8cea86b000 nid=0x4c8c
> waiting on condition [0x00007f8b78104000]
> java.lang.Thread.State: WAITING (parking)
> at sun.misc.Unsafe.park(Native Method)
> - parking to wait for <0x00000005dd703b78> (a
> java.util.concurrent.locks.ReentrantLock$NonfairSync)
> at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:870)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1199)
> at
> java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:209)
> at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285)
> at
> org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegionInMeta(ConnectionManager.java:1274)
> at
> org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegion(ConnectionManager.java:1186)
> at
> org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegion(ConnectionManager.java:1170)
> at
> org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegion(ConnectionManager.java:1127)
> at
> org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.getRegionLocation(ConnectionManager.java:962)
> at
> org.apache.hadoop.hbase.client.HTableMultiplexer.put(HTableMultiplexer.java:206)
> at
> org.apache.hadoop.hbase.client.HTableMultiplexer.put(HTableMultiplexer.java:150)|
>
> When I looked at the issue(HBASE-19260), I recognized the dangerous of to
> allow accessessing multiple threads.
> However, Already create many threads with the limitations
> I think it is very inefficient to allow only one thread access.
>
> | this.metaLookupPool = getThreadPool(
> conf.getInt("hbase.hconnection.meta.lookup.threads.max", 128),
> conf.getInt("hbase.hconnection.meta.lookup.threads.core", 10),
> "-metaLookup-shared-", new LinkedBlockingQueue<Runnable>());|
>
> I want to suggest changing it that allow to have multiple locks.(but not the
> entire thread)
> The following is pseudocode.
>
> |int lockSize = conf.getInt("hbase.hconnection.meta.lookup.threads.max", 128)
> / 2;
> BlockingQueue<ReentrantLock> userRegionLockQueue = new
> LinkedBlockingQueue<ReentrantLock>();
> for (int i=0; i <lockSize; i++) {
> userRegionLockQueue.put(new ReentrantLock());
> }|
>
> thanks.
>
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