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https://issues.apache.org/jira/browse/HBASE-1316?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13034293#comment-13034293
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Joey Echeverria commented on HBASE-1316:
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+1 on Todd et. al.'s design. I think it would be useful to use the JNI thread
for (2) for the following reasons:
1) If the region server process goes down hard, but the machine is still up you
won't see that failure for the long timeout (5 minutes) if the other session is
in a separate JVM.
2) It's probably easier to manage a single JVM during startup and shutdown of a
regionserver.
If nobody minds, I'd like to take a stab it generating a patch for this.
> ZooKeeper: use native threads to avoid GC stalls (JNI integration)
> ------------------------------------------------------------------
>
> Key: HBASE-1316
> URL: https://issues.apache.org/jira/browse/HBASE-1316
> Project: HBase
> Issue Type: Improvement
> Affects Versions: 0.20.0
> Reporter: Andrew Purtell
> Assignee: Berk D. Demir
> Attachments: zk_wrapper.tar.gz
>
>
> From Joey Echeverria up on hbase-users@:
> We've used zookeeper in a write-heavy project we've been working on and
> experienced issues similar to what you described. After several days of
> debugging, we discovered that our issue was garbage collection. There was no
> way to guarantee we wouldn't have long pauses especially since our
> environment was the worst case for garbage collection, millions of tiny,
> short lived objects. I suspect HBase sees similar work loads frequently, if
> it's not constantly. With anything shorter than a 30 second session time out,
> we got session expiration events extremely frequently. We needed to use 60
> seconds for any real confidence that an ephemeral node disappearing meant
> something was unavailable.
> We really wanted quick recovery so we ended up writing a light-weight wrapper
> around the C API and used swig to auto-generate a JNI interface. It's not
> perfect, but since we switched to this method we've never seen a session
> expiration event and ephemeral nodes only disappear when there are network
> issues or a machine/process goes down.
> I don't know if it's worth doing the same kind of thing for HBase as it adds
> some "unnecessary" native code, but it's a solution that I found works.
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