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Tom Jenkinson updated JBTM-2419:
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Fix Version/s: 5.next
Consider reducing the number of JMH perf test forks on PRs
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Key: JBTM-2419
URL:
https://issues.jboss.org/browse/JBTM-2419
Project: JBoss Transaction Manager
Issue Type: Task
Components: Testing
Affects Versions: 5.1.1
Reporter: Michael Musgrove
Fix For: 5.next
We run our JMH tests multiple times in order to estimate run-to-run variance. The [JMH
docs|http://hg.openjdk.java.net/code-tools/jmh/file/tip/jmh-samples/src/m...]
state:
bq. JVMs are complex systems, and the non-determinism is inherent for them. This requires
us to always account the run-to-run variance as the one of the effects in our experiments.
Forking aggregates the results across several JVM launches.
Currently we set the number of forks to 10. We run each test 6 times with each run
lasting 1 min. Since we have 10 tests this means it takes 10 * 10 * 6 minutes for the
benchmarks to complete. In the future we want to keep adding new performance tests and the
time taken to run a PR will become prohibitive. I would like to propose one of the
following solutions:
- reduce the number of forks;
- run a subset of performance tests on each PR and then run them all once a week or so on
the main build
My preference is to reduce the number of forks to 3. Note that the PR requester has the
option to disable performance tests for his PR (by including !PERF in the comment
section).