[
https://issues.apache.org/jira/browse/CASSANDRA-17870?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17630660#comment-17630660
]
Francisco Guerrero commented on CASSANDRA-17870:
------------------------------------------------
Another +1 from me as well (non-committer +1 :( )
> nodetool/rebuild: Add flag to exclude nodes from local datacenter
> -----------------------------------------------------------------
>
> Key: CASSANDRA-17870
> URL: https://issues.apache.org/jira/browse/CASSANDRA-17870
> Project: Cassandra
> Issue Type: Improvement
> Components: Tool/nodetool
> Reporter: Saranya Krishnakumar
> Assignee: Saranya Krishnakumar
> Priority: Normal
> Attachments: fix_nodetool_rebuild.diff
>
> Time Spent: 1.5h
> Remaining Estimate: 0h
>
> During expansion by Dc, when we issue nodetool/rebuild from new dc to rebuild
> the data from other DCs. If src-dc is not passed explicitly, then C* tries to
> rebuild the data from the same (new dc) dc.
> We don’t exclude other nodes in the same DC. Only down sources and the local
> node itself are excluded.
> ```
> // We're _always_ filtering out a local node and down sources
> addSourceFilter(new
> RangeStreamer.FailureDetectorSourceFilter(failureDetector));
> addSourceFilter(new RangeStreamer.ExcludeLocalNodeFilter());
> ```
> We should fix nodetool/rebuild to exclude the local DC (from where we’re
> executing the command) while issuing nodetool/rebuild without passing src dc
>
> Example:
> in a 3 DC cluster,
> ks1 has DC1, DC2
> ks2 has DC1, DC2, DC3
> ks3 has DC2
> now, we add a new DC [DC4] and configured it to all 3 keyspaces.
> if we run rebuild with src DC as DC1, ks3 will fail as it does not have DC1.
> Now, without src DC, the expectation is rebuild would auto pick up DCs for
> each keyspace (let's say ks1: DC1, ks2: DC1, ks3: DC2) and would never fail
> due to under-replicated keyspaces.
> The issue with this approach (without src dc) is that, DC4 is getting picked
> up during rebuild (as src), but DC4 does not have any data yet!
> so, with the patch (ignore local dc flag), DC4 can be filtered out and let
> the database pick up the right dc for each keyspace [from existing 3 DCs].
> -- this is what is the expectation after the patch.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
