Hi team, cross post our question here https://github.com/PrefectHQ/prefect/issues/17452. We have upgraded to the latest prefect version but

Tasks stuck in AwaitingConcurrencySlot

still happens when deployment concurrency == 1

When tasks are stuck in the "AwaitingConcurrencySlot" state with a concurrency limit set to 1, it generally indicates that the tasks are waiting for a slot to become available to execute. Here are some insights and potential solutions: 1. Slot Decay Configuration: Prefect allows you to configure a slot decay rate, which determines how quickly concurrency slots become available again. By setting a higher

slot_decay_per_second

, slots can refresh more quickly, allowing tasks to run more frequently. This can be configured when creating or updating a concurrency limit. More details can be found here. 2. Known Issues: There are known issues related to tasks being stuck in the "AwaitingConcurrencySlot" state. For instance, tasks may not be picked up even when a slot is free due to certain concurrency policies or deployment configurations. Some users have reported that tasks remain stuck if job variables are changed or if deployment concurrency limits are used with subflows. You can find more details and potential workarounds in the following GitHub issues: - Tasks stuck in AwaitingConcurrencySlot - Runs in AwaitingConcurrencySlot not picked up - Deployment concurrency limit leaves jobs stuck In your case, you might want to review the concurrency settings and consider adjusting the slot decay rate. Additionally, checking the specific configuration of your deployment and any changes in job variables could provide further insights into resolving the issue. If these suggestions don't help, following the discussions and updates in the linked GitHub issues might offer more tailored solutions.