[2/2] Add differential flamegraph script #2044
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| negate = False | ||
| # TODO(ddelnano): negation requires switching the type of join from right to left | ||
| # or returning a different DataFrame. This might not be possible with pxl's current | ||
| # functionality, but this should be implemented once it's possible. |
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Ideally the negate parameter would be a script variable. In order to compute the negated flamegraph properly, the how on line 26 must change from right to left in addition to changing the groupby on line 35 to be against the pod1 dataframe.
I tried to implement this by calling merge_and_compute_delta with swapped parameters or to use px.select to pick the correct join type (right vs left). Neither of these seemed to work. I think we might need some additional pxl support in order to accomplish this, but please let me know if you have any ideas.
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If you make this PR target the other one instead of |
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@NickLanam thanks for the tip and I'll give that a try on future PRs to avoid recreating this one. |
…ameGraph` display spec (#2043) Summary: Support rendering differential flamegraphs in the `StackTraceFlameGraph` display spec This change makes it possible to render a [differential flamegraphs](https://www.brendangregg.com/blog/2014-11-09/differential-flame-graphs.html). These are useful for comparing flamegraph profiles against each other in order to see what code paths are called more or less than the baseline profile. When a Vis spec specifies a `differenceColumn`, the widget will render this differential flamegraph. The difference column computes the sample delta between the baseline profile and the new profile. Relevant Issues: N/A Type of change: /kind feature Test Plan: New unit tests pass and pxl script relying on this works as expected (see #2044)  Changelog Message: Add support for rendering differential flamegraphs in the `StackTraceFlameGraph` display spec
Signed-off-by: Dom Del Nano <[email protected]> (cherry picked from commit 12881672c021e47a9090df3335c29f6048e99df3)
…y once it's possible Signed-off-by: Dom Del Nano <[email protected]>
…g issues Signed-off-by: Dom Del Nano <[email protected]>
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| "stacktraceColumn": "stack_trace", | ||
| "countColumn": "count", | ||
| "percentageColumn": "percent", | ||
| "podColumn": "pod", |
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a54f660 added the podColumn column. From testing the original change (everything before a54f660), I would very infrequently receive crashes on this line.
I unfortunately don't have the stack trace handy, but the only thing I can attribute it to is that it's possible for the stacktraceColumn field to result in an undefined or empty value that causes the crash. My suspicion is this doesn't happen for the px/perf_flamegraph script because it forces the scopedStackTrace variable to contain semicolons and (k8s) (source).
Summary: Add differential flamegraph script
This depends on #2043.
Relevant Issues: N/A
Type of change: /kind new-pxl-script
Test Plan: Ran the local UI and verified that the non negated version works as expected
Changelog Message: Add
px/differential_flamegraphscript for comparing flamegraphs profiles between pods. See this post for more background on how to use a differential flamegraph.