RecoverStaleAcquiredTriggers currently only updates TRIGGERS from ACQUIRED→WAITING before deleting the fired trigger record. ReleaseAcquiredTrigger updates from both ACQUIRED and BLOCKED (to cover cases where the trigger state has transitioned) before deleting the FIRED_TRIGGERS row. To avoid leaving a trigger stuck if it is in BLOCKED state, mirror ReleaseAcquiredTrigger by also calling UpdateTriggerStateFromOtherState(..., StateWaiting, StateBlocked) before DeleteFiredTrigger (or otherwise ensure BLOCKED is handled).

HasStaleAcquiredTriggers is described as a “lightweight check”, but it calls SelectInstancesFiredTriggerRecords and iterates all fired trigger records for the instance, which can be sizable under load (lots of EXECUTING records). It also duplicates the same query/scan done again in RecoverStaleAcquiredTriggers after the lock is obtained (two full reads when stale triggers are present). Consider either adjusting the wording, or refactoring to avoid the extra full-table read (e.g., perform the scan only once under lock, or add a cheaper delegate query if feasible).

RecoverStaleAcquiredTriggers determines staleness using rec.FireTimestamp (acquisition time). Since Quartz acquires triggers up to now + IdleWaitTime (and IdleWaitTime is configurable via quartz.scheduler.idleWaitTime), a trigger can legitimately remain in ACQUIRED state longer than the 2-minute floor while the scheduler thread is simply waiting for its scheduled fire time. This can cause premature recovery (flip back to WAITING + delete fired record) and trigger acquisition thrash. Consider basing the cutoff on rec.ScheduleTimestamp (scheduled fire time) instead of acquisition time, or otherwise incorporating the scheduler's acquisition window (IdleWaitTime/batch window) into the threshold.

HasStaleAcquiredTriggers uses rec.FireTimestamp for the stale cutoff as well, which has the same false-positive risk when IdleWaitTime is configured > 2 minutes (or otherwise exceeds the staleness threshold). Align this pre-check with the recovery logic you intend (e.g., compare against rec.ScheduleTimestamp / scheduled fire time).

RecoverStaleAcquiredTriggers catches and logs exceptions per record while running inside the surrounding DoRecoverMisfires transaction. If one of the steps succeeds (e.g., state update) but a later step fails (e.g., DeleteFiredTrigger), the transaction can still be committed, leaving an inconsistent combination like trigger state WAITING with a lingering ACQUIRED fired-trigger row. Consider letting the exception propagate (so the outer logic rolls back and retries later) or otherwise ensuring the recovery of a record is atomic (all-or-nothing) within the transaction.

FiredTriggerRecord.TriggerKey and FireInstanceId are nullable, but this recovery path dereferences them via rec.TriggerKey! / rec.FireInstanceId!. If a delegate ever returns a partial/invalid record (or data is corrupted), this will throw and prevent recovery of other stale records. Consider adding an explicit null check (and skipping/logging the bad record) instead of relying on null-forgiving here.

Catching and swallowing exceptions inside RecoverStaleAcquiredTriggers can lead to committing partial updates (e.g., trigger moved back to WAITING but fired-trigger row not deleted due to a transient error). That can leave inconsistent data and still require later cleanup. Consider letting exceptions propagate (so the outer DoRecoverMisfires rolls back and the misfire handler retries), or otherwise ensuring the state updates + fired-trigger delete happen atomically per record.

When there are no misfires (misfireCount == 0), HasStaleAcquiredTriggers still loads all fired-trigger records for the instance every misfire-handler cycle. On busy schedulers this can be a sizable result set and adds steady-state DB load even when nothing is stale. Consider throttling this check (e.g., only every N cycles / time window) or otherwise reducing the query frequency/size so idle systems don’t pay this cost each scan.

This test validates the ACQUIRED→WAITING transition, but the production code also updates from BLOCKED→WAITING to mirror ReleaseAcquiredTrigger. Adding an assertion that UpdateTriggerStateFromOtherState(..., StateWaiting, StateBlocked, ...) was called would better lock in the intended behavior.

Similar to the earlier test, this one asserts the ACQUIRED→WAITING update but doesn’t assert the BLOCKED→WAITING update that the implementation performs. Adding that assertion would ensure the recovery logic continues to mirror ReleaseAcquiredTrigger for DisallowConcurrentExecution scenarios.

There are now several identical try/catch wrappers around JobStore.ReleaseAcquiredTrigger(...) in this file. Consider extracting a small helper (e.g., SafeReleaseAcquiredTrigger(trigger, contextMessage)) to avoid duplicated logging/error-handling logic and reduce the chance of future call sites missing the protective catch block.

The XML doc for StaleAcquiredTriggerThreshold hard-codes "idleWaitTime ~30s" as an upper bound for normal acquisition, but QuartzSchedulerThread.IdleWaitTime is configurable and can be much larger than 30s. Consider rewording this to avoid implying a fixed/default value, or refer to the configured IdleWaitTime instead of ~30s.

HasStaleAcquiredTriggers calls SelectInstancesFiredTriggerRecords, which (in StdAdoDelegate) issues a "SELECT *" for all FIRED_TRIGGERS rows for this instance, even though only ACQUIRED rows older than the cutoff are needed. If an instance has a high number of in-flight jobs, consider a more selective query (state + timestamp filter) to keep the misfire scan overhead low.