Fix non-atomic async operation creation#619
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nicoloboschi merged 2 commits intomainfrom Mar 19, 2026
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Previously the method performed two separate database round-trips: 1. INSERT into async_operations with no task_payload (null) 2. submit_task → UPDATE to set task_payload A process crash or network error between steps 1 and 2 left a row with task_payload IS NULL permanently. The worker's claim query requires task_payload IS NOT NULL, so these orphaned rows could never be picked up and the queue appeared degraded indefinitely. Fix: build full_payload before the INSERT and include task_payload in the same INSERT statement, making operation creation atomic. submit_task is still called afterwards — for SyncTaskBackend it executes the task immediately (unchanged behaviour); for BrokerTaskBackend it becomes an idempotent UPDATE (payload already set) kept for symmetry.
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Problem
_submit_async_operationcreated database rows in two separate, non-atomic steps:INSERTintoasync_operationswithtask_payload = NULLsubmit_task→ separateUPDATEto settask_payloadA process crash or network error between steps 1 and 2 left a permanently unclaimable row. The worker's claim query requires
task_payload IS NOT NULL, so these orphaned rows would remainpendingforever. Failures of this kind have been observed during periods of high load or API restarts.Fix
Build
full_payloadbefore theINSERTand includetask_payloadin the sameINSERTstatement, making operation creation atomic in a single database round-trip.submit_taskis still called afterwards:SyncTaskBackend: executes the task immediately — unchanged behaviourBrokerTaskBackend: performs an idempotentUPDATE(payload already set by theINSERT), kept for symmetryResult
No more null-payload ghost rows can be created. Existing null-payload rows from prior deployments can be cleaned up by marking them failed (they cannot be claimed regardless).