Review follow-ups for the next-free-GPU dispatcher.
Ambiguous acceptance: the worker transport now raises a typed
AmbiguousDispatchError when the request may have reached the worker but no
acknowledgement came back (websocket closed or timed out before the ack,
unreadable /prompt acknowledgement, request failure after it could have
been received). A connection refusal or an error status stays a definite
failure. The dispatcher no longer restores such a run to the master queue:
it is held as unresolved, claimable by nobody, until the worker delivers,
is seen busy (accepted: collected as usual) or is seen idle without
delivering (never accepted: the original prompt goes back in its place).
While the worker is unreachable the run stays on hold. The immediate
dispatch path does the same and still reports the error to the caller.
Cancellation during a hand-off: the dispatcher hooks the master queue's
wipe_queue and delete_queue_item so a clear or delete reaches runs that
are out of the queue for a hand-off. Preparation and submission are now
separate steps; a run cancelled before submission is dropped together with
its result queues and never sent, while work a worker already accepted
stays owned until its result arrives or the worker is seen done, and is
then discarded instead of reappearing. A Collector that fails or is
interrupted while waiting for its assignment cancels its run the same way,
so the preallocated result queue is removed and an in-flight dispatch
stops before submission. Discarded job ids are remembered so a late
worker cannot recreate their result queue through /distributed/prepare_job.
Also updates the frozen Collector load_balance tooltip in the v1 node
contract fixture.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
