Files
amethyst/geode
Claude 18bd360052 perf: fix O(n²) replay dedup + session-pump backpressure — giant REQs 11x faster
Two server bugs masking each other made a single giant REQ crawl and
then wedge:

LiveEventStore's historical-replay dedup used an immutable Set under an
AtomicReference with copy-on-add — set + id copies the whole set per
streamed event, so large replays were accidentally O(n²) (100k-event
REQ: ~700 events/s, degrading as the response grew). Replaced with a
spin-lock-guarded mutable HashSet (same threads, single contains/add
per critical section).

Fixing that unmasked WebSocketSessionPump's slow-client policy: a fast
replay instantly overflowed the 8192-frame cap — which conflated 'slow
client' with 'replay outruns the socket writer', normal for bulk — and
the 'drop' only closed the internal queue, leaving the socket half-dead
(no EOSE, no close frame, tail silently missing: the likely cause of
the benchmark's 99,998/100,000). Producers are now paced against a full
backlog (bounded blocking wait, consistent with the documented ingest
fanout behavior) and only a client still behind after 30s is dropped,
by actually cancelling the socket.

GiantReqStreamTest guards the regression: 20k-event REQ pre-fix 8.4s
(~2.4k events/s), post-fix 0.7s (~27k events/s), all events + EOSE
delivered. 96 geode tests and the quartz relay/server suites pass.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018saXqYfAa3RvSJoDXK591R
2026-07-03 05:07:39 +00:00
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