Set PoolManager blocksize if urllib3 is v2 #3612
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SamRemis
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Thanks Steve!
Appreciate the deep dive and PR here. Looks good- I was able to reproduce significant bandwidth increases with the new block size from this PR compared to the before.
aws-sdk-python-automation
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* release-1.42.43: Bumping version to 1.42.43 Update endpoints model Update to latest models Set PoolManager blocksize if urllib3 is v2 (#3612)
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While running some S3 performance tests, we noticed that network bandwidth took a significant hit uploading large objects when going from urllib3 v1 to v2. We isolated the bottleneck to this commit: urllib3/urllib3@791c385
urllib3 v2 implemented in-house chunking logic and set a default blocksize of 16KB. This created a bottleneck when transferring larger payloads. Experiments showed that setting 128KB blocksizes was roughly the point where we started getting diminishing returns in performance improvements with large payloads and had negligible impact on small payloads.
We're setting an initial override blocksize of 128KB based on current data. Ideally we won't touch this too much but we can revisit this value if we find users aren't benefitting from it.
PR that added
blocksizesupport: urllib3/urllib3#2348