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https://issues.apache.org/jira/browse/HBASE-9888?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13815084#comment-13815084
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Jean-Daniel Cryans commented on HBASE-9888:
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In 0.94, HLogKey has a {{writeTime}} and we could seek in the current WAL until
we find an edit that's been written after the source was created. It's still
fuzzy since the time that each source actually gets created will differ for
each RS, but at least you wouldn't start replicating old edits.
> HBase replicates edits written before the replication peer is created
> ---------------------------------------------------------------------
>
> Key: HBASE-9888
> URL: https://issues.apache.org/jira/browse/HBASE-9888
> Project: HBase
> Issue Type: Bug
> Reporter: Dave Latham
>
> When creating a new replication peer the ReplicationSourceManager enqueues
> the currently open HLog to the ReplicationSource to ship to the destination
> cluster. The ReplicationSource starts at the beginning of the HLog and ships
> over any pre-existing writes.
> A workaround is to roll all the HLogs before enabling replication.
> A little background for how it affected us - we were migrating one cluster in
> a master-master pair. I.e. transitioning from A <\-> B to B <-> C. After
> shutting down writes from A -> B we enabled writes from C -> B. However,
> this replicated some earlier writes that were in C's HLogs that had
> originated in A. Since we were running a version of HBase before HBASE-7709
> those writes then got caught in a infinite replication cycle and bringing
> down region servers OOM because of HBASE-9865.
> However, in general, if one wants to manage what data gets replicated, one
> wouldn't expect that potentially very old writes would be included when
> setting up a new replication link.
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