[NO-TICKET] Reduce Ruby heap test scenario variation - #154
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**What does this PR do?** This PR adds an additional GC trigger and sleep at the beginning of the Ruby heap test scenarios so that the GC and dynamic sampling rate start with a clean slate. **Motivation:** We've seen these tests flake due to run-to-run variation. Rather than loosening the error ranges in the `expected_profile.json` files, I experimented locally with this "try to create a clean slate" approach and I was getting more accurate results without needing to loosen errors. In particular the "ruby_heap" and "ruby_heap_r4" tests don't do a lot of allocations (e.g. when compared to "ruby_heap_highload" and "ruby_heap_highload_r4") and thus cause a lot more run-to-run variation. (Which kinda makes sense? The less allocations, the less the dynamic sampling rate has to work with, and with small numbers we get more noise in the reads) **Additional Notes:** N/A **How to test the change?** Green CI is the target! If not, we'll keep at it :)
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Hmm looks like this wasn't enough yet... Will keep at it |
ivoanjo
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June 10, 2026 18:00
r1viollet
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Jul 3, 2026
**What does this PR do?** This PR marks all Ruby heap-related tests as flaky, renaming the folders so they don't run by default in CI. **Motivation:** This PR attempts to "stop the bleeding" relating to the Ruby Heap tests being flaky: it's really annoying that these failures keep showing up in other prof-correctness where nothing changed for Ruby. I've started #154 to try to actually fix things, but until we have a good fix in place, let's avoid the annoyance to everyone else. **Additional Notes:** N/A **How to test the change?** Validate that `ruby_heap` tests are no longer running in CI (and CI is still green).
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What does this PR do?
This PR adds an additional GC trigger and sleep at the beginning of the Ruby heap test scenarios so that the GC and dynamic sampling rate start with a clean slate.
Motivation:
We've seen these tests flake due to run-to-run variation. Rather than loosening the error ranges in the
expected_profile.jsonfiles, I experimented locally with this "try to create a clean slate" approach and I was getting more accurate results without needing to loosen errors.In particular the "ruby_heap" and "ruby_heap_r4" tests don't do a lot of allocations (e.g. when compared to "ruby_heap_highload" and "ruby_heap_highload_r4") and thus cause a lot more run-to-run variation.
(Which kinda makes sense? The less allocations, the less the dynamic sampling rate has to work with, and with small numbers we get more noise in the reads)
Additional Notes:
N/A
How to test the change?
Green CI is the target! If not, we'll keep at it :)