[jira] [Created] (HBASE-19358) Improve the stability of splitting log when do fail over

["Jingyun Tian (JIRA)" <ji...@apache.org>]

Jingyun Tian created HBASE-19358:
------------------------------------

             Summary: Improve the stability of splitting log when do fail over
                 Key: HBASE-19358
                 URL: https://issues.apache.org/jira/browse/HBASE-19358
             Project: HBase
          Issue Type: Improvement
          Components: MTTR
    Affects Versions: 0.98.24
            Reporter: Jingyun Tian


Now the way we split log is like the following figure:
!previous-logic.png|thumbnail!
The problem is the OutputSink will write the recovered edits during splitting log, which means it will create one WriterAndPath for each region. If the cluster is small and the number of regions per rs is large, it will create too many HDFS streams at the same time. Then it is prone to failure since each datanode need to handle too many streams.

Thus I come up with a new way to split log.  
!attachment-name.jpg|thumbnail!
We cached the recovered edits unless exceeds the memory limits we set or reach the end, then  we have a thread pool to do the rest things: write them to files and move to the destination.

The biggest benefit is we can control the number of streams we create during splitting log, 
it will not exceeds hbase.regionserver.wal.max.splitters * hbase.regionserver.hlog.splitlog.writer.threads, but before it is hbase.regionserver.wal.max.splitters * the number of region the hlog contains.




--
This message was sent by Atlassian JIRA
(v6.4.14#64029)