Fixed mid-round upload causing server hitch visible to STV spectators#52
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Replaced the synchronous CopyFile with AnyHttp_CopyFile, which spreads
the copy across frames via RequestFrame. Same snapshot-then-upload
behavior, no main-thread stall. Only affected midgameupload (default);
end-of-match uploads already used async PutFile.
Benchmarked on native x86_64 (serveme/tf2-cloud-server, 66.7 tick):
Sync CopyFile Direct PutFile Async CopyFile
(old) (no snapshot) (chosen fix)
100KB 10-14 ms 0.1 ms 0.0 ms
300KB 31-43 ms 0.1 ms 0.0 ms
630KB 64-73 ms 0.1 ms 0.0 ms
1MB 101-111 ms 0.1 ms 0.0 ms
Direct PutFile skips the snapshot copy but risks inconsistent reads if
FlushLog fires mid-copy. Async CopyFile preserves the snapshot with
zero main-thread blocking.
F2
approved these changes
May 23, 2026
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@Arie Thanks for fixing this! ❤️ |
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Trying not to be "sloppy" here. Benchmarked the current code and this alternative to the mid-game log uploads that could cause end-of-round-lag to STV spectators. Benchmarked with realistic log sizes on the serveme docker image, showing the hitch with mid-game uploads, and the hitch being gone with this change:
The synchronous
CopyFileduring mid-game log uploads blocks the main thread for 60-100ms on typical log sizes, suspected to cause a visible hitch for STV spectators that spoils round endings.Replaced with
AnyHttp_CopyFile, which was already built for exactly this purpose, it spreads the file copy across multiple server frames. The log is still copied to a snapshot before uploading, so behavior is identical.Only affects
logstf_midgameupload 1(the default). End-of-match uploads were already async.Benchmark (native x86_64, 66.7 tick / 15ms budget)
Results of 3 benchmark runs on NVMe-based 14600k server.