Track EWMA[1] of task execution time in search threadpool executor #24989
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dakrone
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Assert that >= 0 unless t != null?
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Even if t weren't null, the time should be >= 0; I'll add an assert
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It might be nice to have a test that starts with 0 and continually adds the same number and asserts that eventually the average comes near enough to the number. Or something that asserts that the changes get smaller with additional data points.
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Sure, I've added this test, thanks for the suggestion
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I'm curious about why you chose this. If you don't have a good reason for that number then maybe leave a comment about how this is just a guess.
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It's totally a random pick, I'll add a comment. I'm planning on revisiting the number once all the parts are in place (so I can test different values)
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Probably worth a comment about why the target is a good starting point.
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Good idea, I'll add that
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Thanks for the comments @nik9000, I pushed commits addressing them! |
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This is the first step towards adaptive replica selection (elastic#24915). This PR tracks the execution time, also known as the "service time" of a task in the threadpool. The `QueueResizingEsThreadPoolExecutor` then stores a moving average of these task times which can be retrieved from the executor. Currently there is no functionality using the EWMA yet (other than tests), this is only a bite-sized building block so that it's easier to review. [1]: EWMA = Exponentially Weighted Moving Average
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This is the first step towards adaptive replica selection (#24915). This PR
tracks the execution time, also known as the "service time" of a task in the
threadpool. The
QueueResizingEsThreadPoolExecutorthen stores a moving averageof these task times which can be retrieved from the executor.
Currently there is no functionality using the EWMA yet (other than tests), this
is only a bite-sized building block so that it's easier to review.
[1]: EWMA = Exponentially Weighted Moving Average