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https://issues.apache.org/jira/browse/CASSANDRA-9560?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14578864#comment-14578864
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Fred commented on CASSANDRA-9560:
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Thx, that's great.
FYI I used cassandra-cli and thrift to update the keyspace for durable writes.
It's strange because when you describe the keyspace from cassandra-cli it looks
like durable_writes are disabled but I've got confused when I saw alot of disk
i/o on commitlog files despite setting durable_writes to false.
Would be great with a patch if that's possible.
> Changing durable_writes on a keyspace is only applied after restart of node
> ---------------------------------------------------------------------------
>
> Key: CASSANDRA-9560
> URL: https://issues.apache.org/jira/browse/CASSANDRA-9560
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Environment: Single node
> Reporter: Fred
> Fix For: 2.1.x
>
>
> When mutations for a column family is about to be applied, the cached
> instance of the keyspace metadata is read. But the schema mutation for
> durable_writes hasn't been applied to this cached instance.
> I'm not too familiar with the codebase but after some debugging (2.1.3), it's
> somehow related to:
> {code:title=org.apache.cassandra.db.Mutation.java|borderStyle=solid}
> public void apply()
> {
> Keyspace ks = Keyspace.open(keyspaceName);
> ks.apply(this, ks.metadata.durableWrites);
> }
> {code}
> Where a cached instance of the keyspace is opened but it's metadata hasn't
> been updated with the earlier applied durable_writes mutation, since it seems
> that the cached keyspace instance is lazily build at startup but after that,
> never updated. I'm also a little bit concerned if other values in the cached
> keyspace instance suffers from the same issue, e.g. replication_factor...
> I've seen the same issue in 2.1.5 and the only way to resolve this issue is
> to restart the node to let the keyspace instance cache reload from disk.
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