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Request Cancel for an Activity

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Request Cancel asks an Activity Execution to close gracefully, giving your code a chance to clean up.

When to Request Cancel​

  • A Standalone Activity is no longer needed, and you want it to stop at a safe point rather than be killed mid-attempt.
  • A job was submitted in error, and you want the Activity to release the resources it has already acquired.

A Workflow Activity can't be canceled directly. It receives a cancellation request when its Workflow is canceled, and from that point behaves the same way a Standalone Activity does.

What happens when you Request Cancel an Activity​

The Activity Execution transitions to CancelRequested.

  • If no attempt is running, the execution closes immediately. This doesn't depend on the Activity Heartbeating.
  • If an attempt is running, the request reaches your code through the Activity's Heartbeat. A Cancellation error is raised when the next Heartbeat response is received, and the Activity transitions to canceled status if your code lets that error propagate.
  • If the Activity doesn't Heartbeat, it isn't interrupted mid-attempt. The request takes effect at the next attempt boundary, for example when the Start-To-Close Timeout elapses.

See Cancellation for how your Activity code accepts or ignores a Cancellation.

CLI usage​

temporal activity cancel \
  --activity-id my-activity \
  --reason "No longer needed"

See the CLI reference for temporal activity cancel for all options.

Important considerations​

  • A successful response means the request was accepted, not that the Activity stopped. Your code may complete or fail non-retryably instead of honoring the request.
  • Cancellation can be requested only once. Repeating the request doesn't deliver a second Cancellation.
  • Request Cancel takes precedence over Reset and Pause. See Successive operations.