GET /rounds/stream capped concurrent subscribers with one global
counter (MAX_SUBSCRIBERS=500): anyone opening 500 connections degraded
every other user to polling. The comment called it a defensive cap;
it was actually the vector, since nothing stopped a single source from
exhausting it alone.
RoundEventBroadcaster now also tracks subscribers per client IP,
capped much lower (MAX_SUBSCRIBERS_PER_IP=5). Past that cap, opening
one more stream evicts that same IP's own oldest connection (woken via
a new EVICTED sentinel so the SSE generator closes it promptly) rather
than refusing the new one or letting one abusive IP crowd out unrelated
clients under the old global-only cap. The global cap stays as a
backstop against overall resource exhaustion regardless of source.
Extracted client_ip() (X-Forwarded-For, since Caddy reverse-proxies
every request) out of auth/routes.py into app/api/client_ip.py so the
login/registration throttles (B-33) and this new per-IP cap share one
definition instead of two that could drift apart.
Not implemented: enforcing the connection cap at the Caddy layer
itself, which the proposed fix also suggested - the standard Caddy
image this project uses has no such directive without a third-party
module, and building a custom image felt like a bigger, separate change
than this fix warranted.
Suite grows from 201 to 211 tests. BUGS.md moves B-38 to Previously
fixed.
Frontend dashboards previously found out about state changes only on their
next poll tick (up to 15s, or 3s during a draw) — this adds a push channel
so updates land as soon as they happen instead.
- app/rounds/events.py: a small in-process pub/sub (RoundEventBroadcaster).
The message carries no payload — it's just a "something changed, go
refetch" signal, so it needs no auth and no knowledge of who's allowed to
see what; personalization stays entirely in the existing REST endpoints.
- GET /rounds/stream: an SSE endpoint exposing that channel, with keep-alive
comments so it survives idle periods behind a reverse proxy, and a
defensive MAX_SUBSCRIBERS cap (well above the ~100 concurrent users
expected) — past it, the endpoint returns 503 instead of opening a stream,
and callers just keep working off polling.
- publish() calls added at every point that actually changes what a
dashboard would want to know: new round opened, round status transitions
(closing/drawing/paying_out/closed), a bet or withdrawal broadcast, any
pending tx confirming (bet/withdrawal/payout), a deposit credited, and a
new block tip arriving (the exact moment the "drawing" phase is waiting on).
- Caddyfile: excludes /rounds/stream from gzip encoding, since compression
would buffer output and defeat the point of a live stream.
Single-process only by design for now (no cross-worker fan-out) and the
notification is a generic broadcast rather than a per-user channel — both
are deliberate scope decisions for the current ~100-user, single-container
deployment, not oversights. Polling is left fully in place as a fallback;
this is purely additive.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
davide
