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https://issues.apache.org/jira/browse/HBASE-9934?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13819329#comment-13819329
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Ishan Chhabra commented on HBASE-9934:
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I agree.
Let me setup a graph of HBase clusters for further discussion. Lets say we have
6 clusters, C1..C6.
C1..C3 want to replicate to each other in the NxN fashion (i.e. with no
forwarding) and the following master master replications are setup: C4 <-> C3,
C5 <-> C3 and C6 <-> C5
C4 <-> C3 <-> C5 <-> C6
/ \
C1 - C2
1. The source cluster sets the replication scope for the column family that is
being replicated as SINGLE_HOP_ONLY and the targets clusters do not forward
KeyValues with families that have their scope set as this. The decision on
whether a write should be forwarded ahead thus lies with the source cluster in
this case. This will work if we just had C1..C3 but will *not* work in the
above example since a write from C4 will not have the correct scope set and
will circulate more in C1..C3 than needed. We could say that such a mixed
setting is not supported, but it is hard to prevent someone from shooting
themselves in their foot.
2. Having thought about this, this looks more like a property of the link
(whether it is a part of mesh network or a standard Master-Slave /
Master-Master link). If a link is a part of the mesh network, then *all* writes
coming from that link (including ones that could have originated at a different
cluster) should not be forwarded. To do this setup, we would have to add this
as a property for the peer (in the zookeeper state?) and then when an edit is
sent across a link, it should be marked as "do not forward". This could be a
part of the WALEdit key or we could add support for tags to WALEdit (similar to
cells) and add it there.
Thoughts?
> Suport not forwarding edits in replication
> ------------------------------------------
>
> Key: HBASE-9934
> URL: https://issues.apache.org/jira/browse/HBASE-9934
> Project: HBase
> Issue Type: New Feature
> Components: Replication
> Reporter: Ishan Chhabra
> Priority: Minor
>
> This is to setup NxN replication.
> See background discussion here:
> http://mail-archives.apache.org/mod_mbox/hbase-user/201311.mbox/%3CCAOiuM-4UMmLA7UHMp4hhjpLWUrHDxg1t4tN4aWvnZUMcTxG%2BKQ%40mail.gmail.com%3E
> We can add a new mode in replication to not forward edits from other
> clusters. Not sure what should be done when some clusters are configured with
> this setting and some aren't.
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