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https://issues.apache.org/jira/browse/HBASE-14004?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15043721#comment-15043721
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Yu Li commented on HBASE-14004:
-------------------------------
Nice discussion [~yangzhe1991] and [~Apache9].
FWIW, two questions about the Phil's proposal:
1. What the logic would be like if the durability is set to ASYNC in table
descriptor? Is the following case possible to happen?:
1) entry write into memstore
2) region reassign to other RS thus content in memstore got flushed into
hfile
3) wal sync/write failed
In this case we might run into another kind of inconsistency, say master
cluster has the data but slave doesn't?
2. About {{WAL logging idempotent}}, maybe we also need to consider the
cross-RS case when region assign happens before wal sync acked?
> [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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