Choose the GitHub Actions pending-queue behavior before serializing deployments

One-at-a-time execution and keeping every waiting release are separate concurrency decisions.

Source facts

GitHub Actions permits one running job or workflow per concurrency group. With the default single pending queue, a newly queued run replaces the prior pending run. The optional queue: max setting allows multiple pending runs, up to the documented limit. It cannot be combined with cancel-in-progress: true. Group names are case-insensitive, and ordering follows when jobs begin waiting rather than original dispatch time.

Source: GitHub — Control the concurrency of workflows and jobs.

Applicability

This describes Actions concurrency groups, not an application transaction or rollback mechanism. Current workflow syntax and service limits must be reviewed for the intended deployment design.

DSE recommendation

DSE recommends deciding whether an obsolete waiting release should be replaced or every release must be processed. Name groups deliberately so unrelated workflows cannot collide. Treat cancellation of an executing deployment as a separate decision with a recovery procedure. Document which release identity the deployment should accept after a queue delay and recheck its approval and artifact before making changes. State whether every waiting release is required or only the latest desired state should deploy. Keep that choice with the concurrency group and cancellation setting, and ask the release owner to define how an older approved artifact should be handled after waiting.

Verification

Proposed verification: run several harmless deployment simulations in one group and inspect running, pending, canceled and completed states. Compare the chosen queue behavior with the approved release policy. Exercise a safe cancellation scenario separately and retain the exact group configuration and observed sequence, including any ordering difference from dispatch times.

Official reference

GitHub — Control the concurrency of workflows and jobs. Reviewed October 20, 2026.