Fix connection throttle cleanup wiping the whole tracker#14011
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gunjanjaswal wants to merge 1 commit into
Open
Fix connection throttle cleanup wiping the whole tracker#14011gunjanjaswal wants to merge 1 commit into
gunjanjaswal wants to merge 1 commit into
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The stale-entry cleanup compared a stored timestamp directly against the throttle duration (`time > connectionThrottle`). A real epoch timestamp is always far greater than the configured duration (default 4000ms), so the predicate matched every entry and cleared the entire throttleTracker every ~200 connections. Between cleanups a client could reconnect around the cycle and dodge the per-IP throttle. Compare elapsed time instead (`currentTime - time > connectionThrottle`), matching the check used a few lines above where the same `currentTime` is already computed. Fixes PaperMC#13984.
electronicboy
approved these changes
Jun 30, 2026
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Problem
The connection throttle cleanup in
ServerHandshakePacketListenerImplwipes the entirethrottleTrackerevery ~200 connections. The cleanup predicate compares a stored timestamp against the throttle duration:timeis an epoch-millisecond timestamp (~1.7e12);connectionThrottleis a duration (default 4000ms). Sotime > connectionThrottleis always true and every entry is removed. The check a few lines above already does it correctly:Within a cleanup cycle the per-IP throttle works, but every 200th connection clears the map, so a client can time reconnects around the cleanup and slip past the throttle.
Fix
Compare elapsed time, reusing the
currentTimealready computed in the same block:This is a content-only change to the existing added line in the patch, so it applies cleanly with no rebuildPatches churn.
Fixes #13984.