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Jonathan Ellis commented on CASSANDRA-10326: -------------------------------------------- bq. I would recommend that - until we can assess the GC behavioural changes further, we revert CASSANDRA-7486 +1 > Performance is worse in 3.0 > --------------------------- > > Key: CASSANDRA-10326 > URL: https://issues.apache.org/jira/browse/CASSANDRA-10326 > Project: Cassandra > Issue Type: Bug > Reporter: Benedict > Priority: Critical > Fix For: 3.0.x > > > Performance is generally turning out to be worse after 8099, despite a number > of unrelated performance enhancements being delivered. This isn't entirely > unexpected, given a great deal of time was spent optimising the old code, > however things appear worse than we had hoped. > My expectation was that workloads making extensive use of CQL constructs > would be faster post-8099, however the latest tests performed with very large > CQL rows, including use of collections, still exhibit performance below that > of 2.1 and 2.2. > Eventually, as the dataset size grows large enough and the locality of access > is just right, the reduction in size of our dataset will yield a window > during which some users will perform better due simply to improved page cache > hit rates. We seem to see this in some of the tests. However we should be at > least as fast (and really faster) off the bat. > The following are some large partition benchmark results, with as many as 40K > rows per partition, running LCS. There are a number of parameters we can > modify to see how behaviour changes and under what scenarios we might still > be faster, but the picture painted isn't brilliant, and is consistent, so we > should really try and figure out what's up before GA. > [trades-with-flags (collections), > blade11b|http://cstar.datastax.com/graph?stats=f0a17292-5a13-11e5-847a-42010af0688f&metric=op_rate&operation=1_user&smoothing=1&show_aggregates=true&xmin=0&xmax=4387.02&ymin=0&ymax=122951.4] > [trades-with-flags (collections), > blade11|http://cstar.datastax.com/graph?stats=e25aaaa0-5a13-11e5-ae0d-42010af0688f&metric=op_rate&operation=1_user&smoothing=1&show_aggregates=true&xmin=0&xmax=4424.75&ymin=0&ymax=130158.6] > [trades (no collections), > blade11|http://cstar.datastax.com/graph?stats=9b7da48e-570c-11e5-90fe-42010af0688f&metric=op_rate&operation=1_user&smoothing=1&show_aggregates=true&xmin=0&xmax=2682.46&ymin=0&ymax=142547.9] > [~slebresne]: will you have time to look into this before GA? -- This message was sent by Atlassian JIRA (v6.3.4#6332)