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https://issues.apache.org/jira/browse/CASSANDRA-9558?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14602554#comment-14602554
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Benedict commented on CASSANDRA-9558:
-------------------------------------
Can we answer my question before forging ahead and changing any default pooling
settings? Like I say, it's not at all necessarily a *bug*. It is quite likely
that this configuration improves throughput for many normal cluster
configurations, and has negative implications only for very small clusters. We
want the fewest connections we can get away with; perhaps, the client should
automatically scale the connections based on throughput or cluster size.
We haven't undertaken sufficient investigation to say with certainty, but it
seems that what we are doing here is increasing the CPU _overhead_ per
operation in order to _saturate_ the processing capacity of each box. However
when there are more machines, or more simulated clients, this increased
overhead is highly likely to reduce throughput due to the increased overhead.
What we should probably do on our end is implement CASSANDRA-8466, since this
is how a majority of users really use their clusters: many clients, not one
client with many connections in the Java driver.
> Cassandra-stress regression in 2.2
> ----------------------------------
>
> Key: CASSANDRA-9558
> URL: https://issues.apache.org/jira/browse/CASSANDRA-9558
> Project: Cassandra
> Issue Type: Bug
> Reporter: Alan Boudreault
> Assignee: Andy Tolbert
> Fix For: 2.2.0 rc2
>
> Attachments: 2.1.log, 2.2.log, CASSANDRA-9558-2.patch,
> CASSANDRA-9558-ProtocolV2.patch, atolber-CASSANDRA-9558-stress.tgz,
> atolber-trunk-driver-coalescing-disabled.txt,
> stress-2.1-java-driver-2.0.9.2.log, stress-2.1-java-driver-2.2+PATCH.log,
> stress-2.1-java-driver-2.2.log, stress-2.2-java-driver-2.2+PATCH.log,
> stress-2.2-java-driver-2.2.log
>
>
> We are seeing some regression in performance when using cassandra-stress 2.2.
> You can see the difference at this url:
> http://riptano.github.io/cassandra_performance/graph_v5/graph.html?stats=stress_regression.json&metric=op_rate&operation=1_write&smoothing=1&show_aggregates=true&xmin=0&xmax=108.57&ymin=0&ymax=168147.1
> The cassandra version of the cluster doesn't seem to have any impact.
> //cc [~tjake] [~benedict]
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