perf(exporter): retain pre-compressed deflate payloads in memory - #6059
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another-rex merged 2 commits intoSep 24, 2026
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another-rex merged 2 commits into
another-rex merged 2 commits into
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Stage pre-compressed deflate payloads in memory on vulnMeta instead of writing 2M+ small files to local scratch disk. Eliminates ext4 directory inode lock contention and 4M+ file syscalls during ZIP creation. Also updates -cleanup-scratch-dir to default to true.
michaelkedar
previously approved these changes
Sep 23, 2026
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| compressedBytes := compBuf.Bytes() | ||
| compressedBytes := bytes.Clone(compBuf.Bytes()) |
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Is the clone here actually necessary?
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Not really, I guess it resizes the buffer down to the right size so we don't have the extra room taken up. But probably not a big deal.
compBuf is scoped to each loop iteration and never mutated. Using compBuf.Bytes() directly avoids 2M heap allocations and memmoves during download.
michaelkedar
approved these changes
Sep 23, 2026
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I give up on saving memory by writing to disk.
Previously, the exporter staged ~2M pre-compressed
.deflatefiles to the local scratch disk in Phase 1, then re-opened and streamed them into ZIP archives during Phase 2. On ext4 filesystems with millions of entries in a single directory, this caused a lot of stall time and contention. (up to 87.6% stall time in test), causing the exporter to overrun the 15 minutes.The guess for why this is only happening in test currently is because of how long the node has been live for, keeping all those files on disk, increasing the disk pressure.
Because all 2M compressed payloads only consume ~8.5 GiB in total (well within the 50 GiB
GOMEMLIMITand 60 GiB memory limit), we now retain the pre-compressed bytes directly in memory onvulnMeta.Also changes
-cleanup-scratch-dirdefault totruenow that the scratch directory only holds ~47 temporary.zipfiles (<1ms deletion).agy