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https://issues.apache.org/jira/browse/CASSANDRA-6199?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13794581#comment-13794581
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Jonathan Ellis commented on CASSANDRA-6199:
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bq. Do not trash first/last 10% of readings
Would be nice to fix last but I don't see how first 10% can stay valid b/c of
JVM warmup. Note that
bq. Short warm-up period, which is ignored for summary
is problematic b/c this does affect server results (compaction) during the
post-warmup phase.
bq. Per thread Random
FBUtilities has an implementation, incidentally.
> Improve Stress Tool
> -------------------
>
> Key: CASSANDRA-6199
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6199
> Project: Cassandra
> Issue Type: Improvement
> Components: Tools
> Reporter: Benedict
> Assignee: Benedict
> Priority: Minor
>
> The stress tool could do with sprucing up. The following is a list of
> essential improvements and things that would be nice to have.
> Essential:
> - Reduce variability of results, especially start/end tails. Do not trash
> first/last 10% of readings
> - Reduce contention/overhead in stress to increase overall throughput
> - Short warm-up period, which is ignored for summary (or summarised
> separately), though prints progress as usual. Potentially automatic detection
> of rate levelling.
> - Per thread Random
> Nice to have:
> - Calculate and print stdev and mean
> - Add batched sequential access mode (where a single thread performs
> batch-size sequential requests before selecting another random key) to test
> how key proximity affects performance
> - Auto-mode which attempts to establish the maximum throughput rate, by
> varying the thread count (or otherwise gating the number of parallel
> requests) for some period, then configures rate limit or thread count to test
> performance at e.g. 30%, 50%, 70%, 90%, 120%, 150% and unconstrained.
> - Auto-mode could have a target variance ratio for mean throughput and/or
> latency, and completes a test once this target is hit for x intervals
> Also, remove the skip-key setting, as it is currently ignored. Unless
> somebody knows the reason for it.
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