Pankaj Kumar reassigned HBASE-9888:

    Assignee:     (was: Pankaj Kumar)

> 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
>            Priority: Major
> 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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