Stop extra copy of exponential histogram buckets #5020
Merged
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Currently an extra copy of exponential histogram buckets is made during collection, which causes extra memory allocation when temporality is cumulative.
This PR addresses it by mutating the buckets instead of operating on a copy.
Here's the the
HistogramCollectBenchmark
before:And after:
The key bit is a reduction in
HistogramCollectBenchmark.recordAndCollect:·gc.alloc.rate
forCUMULATIVE
temporality from4.355 MB/sec
to3.806 MB/sec
. A modest but non-negligible improvement.