Round 1 (b6636053 + 4ffefa60) shipped the keepalive parser, 1.5x idle
disconnect per MQTT spec section 4.4, and a per-minute status-push
diagnostic. Reporter's follow-up pcap showed the round-1 logic was
correct as designed, but the actual root cause sits one layer down:
the same OrcaSlicer install that stays connected to a real Bambu P1S
indefinitely sends zero MQTT packets after the initial CONNECT /
SUBSCRIBE / pushall / get_version burst - no PINGREQ at all - so any
spec-compliant server disconnects it at keep_alive x 1.5.
Real Bambu firmware does not enforce section 4.4. The reporter's
identical Orca install holds idle sessions against real hardware on
the same network. Spec compliance was itself the regression.
Fix: after CONNECT/auth, drop the application-level read timeout
entirely (read_timeout = None) and set SO_KEEPALIVE on the underlying
socket so the OS TCP stack reaps dead connections within a few
minutes. The 60s pre-CONNECT cap is preserved - a client that opens
TCP but never sends CONNECT still gets reaped. Negotiated keepalive
is still parsed and now logged at INFO ("MQTT client X authenticated
(negotiated keepalive=Ys, idle disconnect disabled)") for support-
bundle visibility.
After this ships, OrcaSlicer should stay connected to the VP
indefinitely while idle and reconnect cleanly on real network drops.
The publish_json code -4 and -6010 errors reported in the original
thread were downstream of this disconnect and should also clear.
maziggy
7a9c78c32c