Detailed read/write statistics and histograms#244
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abzmr wants to merge 3 commits intoarchiecobbs:masterfrom
Open
Detailed read/write statistics and histograms#244abzmr wants to merge 3 commits intoarchiecobbs:masterfrom
abzmr wants to merge 3 commits intoarchiecobbs:masterfrom
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added 2 commits
October 10, 2025 21:39
Write stats now provide more details to gauge effects of blocksize choice: write_hits_fullblock - Block was in cache and was fully overwritten write_hits_partialblock - Block was in cache and was partially overwritten write_misses_fullblock - Full block was newly introduced into cache write_misses_partialblock - Block was downloaded(*) and then partially overwritten (*) Note that zero-cache has already been passed, so download will always be attempted even if known to be all-zero or non-existent.
For operations executed via the FUSE and NBD front-ends, detailed statistics are now recorded. These may help to evaluate blocksize choice for the specific use case. "Requestbytes" and "requestalign" provide histograms on front-end request size and alignment, which are independent of any s3backer settings. "Requestalign" smaller than blocksize means initial partial block access per front-end request. "Fullblocks" and "trailerbytes" provide histograms on the number of complete blocks resp. trailing partial blocks per front-end request. These are available separately for read and write requests; and also trim in case of NBD.
FUSE uses fallocate(PUNCH_HOLE) to pass TRIM requests. And since that is the only variant actually executed in fuse_ops.c, record these requests into TRIM histogram.
Owner
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Two suggestions on this patch... Instead of replacing counters, just add new ones. E.g., keep The histogram stuff might be better off in a new file, i.e., a peer of |
Author
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Thanks for the good suggestions. |
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Improve statistics to get insights into actual FUSE/NBD access patterns. See both commit comments for more details.
These were some quick hacks that work fine, and could possibly use some more beautification :)
Stats file format is changed somewhat, which might bite people that process it.