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ZhaoYang edited comment on CASSANDRA-16036 at 9/18/20, 7:16 AM: ---------------------------------------------------------------- !16036_128mb.png! Above is write perf in mixed-read-write test using 128mb cache between 16036-disable-chunk-cache and its base line. Disabling chunk cache significantly improves latency. (read perf is similar to write perf) !15229_128mb.png! Above is write perf in mixed-read-write test using 128mb cache between 15229-disable-chunk-cache and 15229-improved-buffer-pool. Disabling chunk cache show some improvement on latency. (read perf is similar to write perf) was (Author: jasonstack): !16036_128mb.png! Above is write perf in mixed-read-write test between 16036-disable-chunk-cache and its base line. Disabling chunk cache significantly improves latency. (read perf is similar to write perf) !15229_128mb.png! Above is write perf in mixed-read-write test between 15229-disable-chunk-cache and 15229-improved-buffer-pool. Disabling chunk cache show some improvement on latency. (read perf is similar to write perf) > Add flag to disable chunk cache and disable by default > ------------------------------------------------------ > > Key: CASSANDRA-16036 > URL: https://issues.apache.org/jira/browse/CASSANDRA-16036 > Project: Cassandra > Issue Type: Bug > Components: Legacy/Local Write-Read Paths > Reporter: David Capwell > Assignee: David Capwell > Priority: Normal > Fix For: 4.0-beta > > Attachments: 15229_128mb.png, 16036_128mb.png, > async-profile.collapsed.svg, > clustering-in-clause_latency_selects_baseline.png, > clustering-in-clause_latency_selects_baseline_attempt3.png, > clustering-in-clause_latency_under90_selects_baseline.png, > clustering-in-clause_latency_under90_selects_baseline_attempt3.png, > clustering-slice_latency_selects_baseline.png, > clustering-slice_latency_under90_selects_baseline.png, > medium-blobs_latency_selects_baseline.png, > medium-blobs_latency_under90_selects_baseline.png, > partition-single-row-read_latency_selects_baseline.png, > partition-single-row-read_latency_under90_selects_baseline.png > > > Chunk cache is enabled by default and doesn’t have a flag to disable without > impacting networking. In performance testing 4.0 against 3.0 I found that > reads were slower in 4.0 and after profiling found that the ChunkCache was > partially to blame; after disabling the chunk cache, read performance had > improved. > {code} > 40_w_cc-selects.hdr > #[Mean = 11.50063, StdDeviation = 13.44014] > #[Max = 482.41254, Total count = 316477] > #[Buckets = 25, SubBuckets = 262144] > 40_wo_cc-selects.hdr > #[Mean = 9.82115, StdDeviation = 10.14270] > #[Max = 522.36493, Total count = 317444] > #[Buckets = 25, SubBuckets = 262144] > {code} -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org