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https://issues.apache.org/jira/browse/HBASE-14004?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14978038#comment-14978038
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Heng Chen commented on HBASE-14004:
-----------------------------------
On the assumption that HDFS sync successfully and do response,
but RS NOT get this response because of network disconnect. As for RS, sync
timeout but data persisted on HDFS. [~carp84]
As [~Apache9] mentioned,
{quote}
A simple solution is killing the regionserver when we fail to sync WAL which
means we will never rollback memstore but reconstruct it using WAL.
{quote}
It may cause two problems.
* we may do mutation twice, (it seems no problems if mutation is incr/append
in current logic?)
* All RS will be killed if network between RS and NN disconnected shortly.
> [Replication] Inconsistency between Memstore and WAL may result in data in
> remote cluster that is not in the origin
> -------------------------------------------------------------------------------------------------------------------
>
> Key: HBASE-14004
> URL: https://issues.apache.org/jira/browse/HBASE-14004
> Project: HBase
> Issue Type: Bug
> Components: regionserver
> Reporter: He Liangliang
> Priority: Critical
> Labels: replication, wal
>
> Looks like the current write path can cause inconsistency between
> memstore/hfile and WAL which cause the slave cluster has more data than the
> master cluster.
> The simplified write path looks like:
> 1. insert record into Memstore
> 2. write record to WAL
> 3. sync WAL
> 4. rollback Memstore if 3 fails
> It's possible that the HDFS sync RPC call fails, but the data is already
> (may partially) transported to the DNs which finally get persisted. As a
> result, the handler will rollback the Memstore and the later flushed HFile
> will also skip this record.
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