[JohnyKid123]

Purpose

Re-dispatch cancellation for workflow instances left in Cancelling after a crash or a lost enqueue. This is the Phase B follow-up to elsa-workflows#9115 and does not change Phase A's mark scope.

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Scope

Select one primary concern:

• Bug fix (behavior change)
• Refactor (no behavior change)
• Documentation update
• Formatting / code cleanup
• Dependency / build update
• New feature

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Description

Problem

Phase A (elsa-workflows#9115, for elsa-workflows#5187) marks a suspended instance Cancelling before dispatch. A crash after that mark and before the cancellation request is enqueued leaves the row Running / Cancelling. Nothing on main looks at that row again. InterruptedRecoveryScanner only restarts Interrupted instances.

Solution

This PR is stacked on fix/workflow-cancellation-5187-phase-a so the review diff is recovery only. It targets the 3.11 milestone, same as elsa-workflows#9115. Phase A stays as it is.

• CancellingRecoveryScanner selects running, non-executing instances in Cancelling whose UpdatedAt is older than RuntimeOptions.CancellingRecoveryThreshold (default 5 minutes, same order of magnitude as InactivityThreshold). TimeSpan.Zero disables the scan. Pages use CancellingRecoveryBatchSize (default 100).
• The scan reads the matching rows first, then claims each one with TryTransitionSubStatusAsync: expected Cancelling plus the stored UpdatedAt, next Cancelling, new stamp from the clock. A concurrent Cancelled commit or restore makes the compare-and-swap fail, and that row is not re-dispatched. Cancelling → Cancelling is now a permitted transition so the claim can refresh the stamp. Entering Cancelling is still Suspended only. Pending and Interrupted stay unmarked.
• After a successful claim, the scan calls IWorkflowCancellationDispatcher with the instance id only. Cancellation is idempotent. The request omits PreviousSubStatus and CancellingAt, so an observed failure of this re-dispatch leaves Cancelling in place for the next scan. The new stamp also makes an older restore compare-and-swap miss the row.
• The scan runs at startup (RecoverCancellingWorkflowsStartupTask) and every 5 minutes (RecoverCancellingWorkflowsTask), both single-node, registered on the runtime feature and the shell feature. InterruptedRecoveryScanner and RestartInterruptedWorkflowsTask are unchanged.
• No Studio UI.

Depends on elsa-workflows#9115. Related to elsa-workflows#5187.

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Verification

net10.0:

• dotnet test core/test/unit/Elsa.Workflows.Runtime.UnitTests/Elsa.Workflows.Runtime.UnitTests.csproj --filter FullyQualifiedName~CancellingRecoveryScannerTests — 6 passed
• dotnet test core/test/unit/Elsa.Workflows.Management.UnitTests/Elsa.Workflows.Management.UnitTests.csproj --filter FullyQualifiedName~MemoryWorkflowInstanceStoreTests — 20 passed

Steps:

1. Leave a running, non-executing instance in Cancelling with UpdatedAt older than the threshold. The scanner claims it (stamp moves, sub-status stays Cancelling) and dispatches cancellation without restore metadata.
2. Move the stamp, finish the instance as Cancelled, or restore it before the claim. The compare-and-swap fails and cancellation is not re-dispatched.
3. A Cancelling row newer than the threshold, an executing Cancelling row, and Suspended, Pending, and Interrupted rows are left alone.

Expected outcome: only stale, idle Cancelling rows are claimed and re-dispatched. Phase A still marks only Suspended instances.

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Screenshots / Recordings (if applicable)

No UI changes.

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Checklist

• The PR is focused on a single concern
• Commit messages follow the recommended convention
• Tests added or updated (if applicable)
• Documentation updated (if applicable)
• No unrelated cleanup included
• All tests pass — the targeted unit tests above. Full CI is the remaining check.

AI assistance

AI assistance was used for implementation and tests. The recovery claim is a Cancelling stamp refresh on the existing TryTransitionSubStatusAsync primitive from elsa-workflows#9115.

  

[cursor]

@greptileai please review this recovery-only follow-up to elsa-workflows#9115. Phase A mark scope is unchanged.