[
https://issues.apache.org/jira/browse/HBASE-14949?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15074871#comment-15074871
]
Heng Chen commented on HBASE-14949:
-----------------------------------
Yeah, it has little relationship with HBASE-15046.
But if we want to remove 'rollback memstore' logic, we still need move sync
WAL before update Memstore.
Back to this issue.
I agree we use two steps to solve upgrade problems.
It will be better if we use a switch which store in System Table, after
upgrade finished, we can switch on manually to use new WAL logic.
> Skip duplicate entries when replay WAL.
> ---------------------------------------
>
> Key: HBASE-14949
> URL: https://issues.apache.org/jira/browse/HBASE-14949
> Project: HBase
> Issue Type: Sub-task
> Reporter: Heng Chen
> Attachments: HBASE-14949.patch, HBASE-14949_v1.patch,
> HBASE-14949_v2.patch
>
>
> As HBASE-14004 design, there will be duplicate entries in different WAL. It
> happens when one hflush failed, we will close old WAL with 'acked hflushed'
> length, then open a new WAL and write the unacked hlushed entries into it.
> So there maybe some overlap between old WAL and new WAL.
> We should skip the duplicate entries when replay. I think it has no harm to
> current logic, maybe we do it first.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
