With the worker soft clock the host's per-run timer is only the transport
deadline and the kill G is armed by the worker's soft notice, so a worker
whose watchdog never sends one (the design treats the worker as untrusted)
held the run, the key's slot and the tag's BadResourceUnavailable forever;
a deferred run had no host clock at all.
WorkerConnection now tracks evaluation progress (any Results frame, or the
submit that made the worker busy again). The heartbeat monitor kills the
worker when evaluations are outstanding and nothing progressed for
3 x the largest outstanding T + G plus the silence limit:
WorkerExitReason.KilledUnresponsive (metric reason killed_unresponsive), no
culprit, attributed like a heartbeat kill (suspects, no strike on a shard).
A legitimate run has answered or been killed by T + G.
Test seams: ProgressCeilingOverride, DropSoftNoticesForTest. Tests: a worker
whose notices are dropped (G = 60 s, so its own fail-fast cannot end it) is
killed KilledUnresponsive after the 1.5 s ceiling and the run is released
(with the check disabled the test times out); positive control: 20 queued
150 ms runs behind one thread under a 1 s ceiling are all answered.
Joseph Doherty
3f5fdd1d90