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https://issues.apache.org/jira/browse/CASSANDRA-10423?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14939755#comment-14939755
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Roger Schildmeijer commented on CASSANDRA-10423:
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I have 48 nodes in total. Four dcs with 12 nodes each. Using RF=3. The LWT rate
is very low, single digit lwt requests per second. My usage of LWT is not
likely to contend a lot.
>From a single node with 1-2months of uptime:
org.apache.cassandra.metrics.ClientRequest.CASWrite.ConditionNotMet: 946
org.apache.cassandra.metrics.ClientRequest.CASWrite.ContentionHistogram: 50 -
99th are all 1.0, Max is 12. (count 787)
org.apache.cassandra.metrics.ClientRequest.CASWrite.Timeouts has remained
static since the node move was done.
> Paxos/LWT failures when moving node
> -----------------------------------
>
> Key: CASSANDRA-10423
> URL: https://issues.apache.org/jira/browse/CASSANDRA-10423
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Environment: Cassandra version: 2.0.14
> Java-driver version: 2.0.11
> Reporter: Roger Schildmeijer
>
> While moving a node (nodetool move <newtoken>) we noticed that lwt started
> failing for some (~50%) requests. The java-driver (version 2.0.11) returned
> com.datastax.driver.core.exceptions.WriteTimeoutException: Cassandra timeout
> during write query at consistency SERIAL (7 replica were required but only 0
> acknowledged the write). The cluster was not under heavy load.
> I noticed that the failed lwt requests all took just above 1s. That
> information and the WriteTimeoutException could indicate that this happens:
> https://github.com/apache/cassandra/blob/cassandra-2.0.14/src/java/org/apache/cassandra/service/StorageProxy.java#L268
> I can't explain why though. Why would there be more cas contention just
> because a node is moving?
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