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Olivier Michallat commented on CASSANDRA-9558: ---------------------------------------------- I ran tests on physical hardware that confirm that the number of connections is a major factor. As was explained before, 2.1.x versions of the driver are currently forcing a single connection per host when protocol v3 is in use. [JAVA-738|https://datastax-oss.atlassian.net/browse/JAVA-738] (scheduled for 2.1.7 and 2.2.0-rc2) will make the pool size dynamic again. Running cassandra-stress with driver 2.1.6 and protocol v3 (1 connection), I get a performance hit of about 25%. Switching to a 2.1.7 snapshot with protocol v3 and 8 connections per host, I'm back to the same as 2.0.x driver / protocol v2. > 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: T Jake Luciani > Fix For: 2.2.x > > 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] -- This message was sent by Atlassian JIRA (v6.3.4#6332)