[
https://issues.apache.org/jira/browse/CASSANDRA-13079?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15783345#comment-15783345
]
Marcus Olsson commented on CASSANDRA-13079:
-------------------------------------------
Good to hear that --full did the trick.
I think it would be a good idea for this type of scenario to change the repair
state during replication altering, but I'm not sure if that's always the case.
In the scenario for adding a new data center I believe the recommended approach
is to disable auto bootstrap and instead change the replication factor when the
full data center is up and running. And then run "nodetool rebuild" to stream
over the data from an existing data center. In that scenario it could be large
amounts of data that would get marked as unrepaired and would have to be
repaired again causing unnecessary load on the cluster.
Another scenario is reducing the replication factor, in that case I don't think
there would be a need to alter the repair state since there should only be less
replicas, but to me it feels like this scenario would be easier to cover than
the multi-dc one.
Unless I'm missing something with the multi-dc scenario I'd say this would need
to be implemented as an optional feature to avoid complexity(both operational
and in code), but I'm not sure how this would be done or how feasible it is
currently. Perhaps by adding some metadata to the schema altering statements?
> Repair doesn't work after several replication factor changes
> ------------------------------------------------------------
>
> Key: CASSANDRA-13079
> URL: https://issues.apache.org/jira/browse/CASSANDRA-13079
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Environment: Debian
> Reporter: Vladimir Yudovin
> Priority: Critical
>
> Scenario:
> Start two nodes cluster.
> Create keyspace with rep.factor *one*:
> CREATE KEYSPACE rep WITH replication = {'class': 'SimpleStrategy',
> 'replication_factor': 1};
> CREATE TABLE rep.data (str text PRIMARY KEY );
> INSERT INTO rep.data (str) VALUES ( 'qwerty');
> Run *nodetool flush* on all nodes. On one of them table files are created.
> Change replication factor to *two*:
> ALTER KEYSPACE rep WITH replication = {'class': 'SimpleStrategy',
> 'replication_factor': 2};
> Run repair, then *nodetool flush* on all nodes. On all nodes table files are
> created.
> Change replication factor to *one*:
> ALTER KEYSPACE rep WITH replication = {'class': 'SimpleStrategy',
> 'replication_factor': 1};
> Then *nodetool cleanup*, only on initial node remained data files.
> Change replication factor to *two* again:
> ALTER KEYSPACE rep WITH replication = {'class': 'SimpleStrategy',
> 'replication_factor': 2};
> Run repair, then *nodetool flush* on all nodes. No data files on second node
> (though expected, as after first repair/flush).
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
