decentraland / archipelago-workers / 30665076602

93%

main: 79%

Pull #128

github

fix: release discarded fetch bodies and stop ban sweeps overlapping

Both raised in review.

Unconsumed response bodies. @dcl/fetch-component cancels the bodies it discards
internally and says why in its own source: an unconsumed undici body pins its
socket and buffers the received bytes until GC. It also hands ownership of the
returned response to the caller, and both adapters dropped it on the non-OK
path without reading or cancelling it.

The ban check is the one that matters: it runs on every WS handshake, so a
gatekeeper returning 5xx — the outage the fail-open exists to survive — would
pin a socket and buffer its bytes per connecting player, leaking worst exactly
when the system is already degraded. The deny list has the same bug bounded by
its 5 minute TTL, so at most one body per window. Both now cancel.

Overlapping ban sweeps. setInterval does not await an async callback, so a
sweep slower than the interval had the next one start on top of it. Each sweep
carries its own budget of BAN_SWEEP_CONCURRENCY in-flight checks, so overlapping
them multiplies load on comms-gatekeeper — and a slow gatekeeper is what makes a
sweep outrun its interval in the first place, so the pile-up compounds the
condition that caused it. Reachable rather than theoretical: a sweep takes up to
ceil(peers / 20) * 1s against the 1s per-check timeout, so it outruns the 30s
default past roughly 600 peers.

Guarded against re-entry, and the skip is logged: it means either the interval
is too short for the peer count or the ban check is degraded. A guard rather
than a self-scheduling setTimeout keeps the fixed cadence and the unref().

Both fixes are mutation-tested: removing either one kills exactly its own test.

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