Nicolas Liochon created HBASE-11226:
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             Summary: Document and increase the default value for 
hbase.hstore.flusher.count
                 Key: HBASE-11226
                 URL: https://issues.apache.org/jira/browse/HBASE-11226
             Project: HBase
          Issue Type: Bug
          Components: regionserver
    Affects Versions: 0.98.2, 0.99.0
            Reporter: Nicolas Liochon
            Assignee: Nicolas Liochon
             Fix For: 0.99.0, 0.98.3


HBASE-6466 add the possibility to have multiple threads for the flusher.
The default value is 1, but this should be incremented to 2 reasons:
 - I've observed that the flush of a region can be delayed because another is 
in progress. During a write load, this leads to an increased latency because 
the memstore size increases and then block the client
 - if, by accident, a flusher hits a slow or bad datanode, all the flush will 
have to wait until the timeouts expires. With 2 or more flushers and some luck 
the other regions will be flushed by the second thread. 

Lastly this setting is important enough to be documented in the standard hbase 
site imho.

I think it's important enough to go in the .98 branch as well
There will be an impact: as the flush won't be queued (or less queued) we may 
have more compactions...





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