fix(core): Reduce risk of race condition during workflow activation loop #13186
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ivov
commented
Feb 11, 2025
| @@ -90,7 +90,6 @@ export class ActiveWorkflowManager { | |||
| await this.addActiveWorkflows('init'); | |||
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| await this.externalHooks.run('activeWorkflows.initialized'); | |||
| await this.webhookService.populateCache(); | |||
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We are already populating the cache immediately after adding the webhooks for every activated workflow.
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Not related to this PR, but noticed this: Combined with #13191, we actually now query all webhooks multiple time and add them to the cache multiple times. Shouldn't we only add that one specific WFs webhooks in the addWebhooks?
n8n-assistant
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tomi
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Feb 11, 2025
tomi
requested changes
Feb 11, 2025
tomi
approved these changes
Feb 13, 2025
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| Project |
n8n
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| Branch Review |
cat-637
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| Run status |
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| Run duration | 04m 37s |
| Commit |
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| Committer | Tomi Turtiainen |
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5
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436
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| View all changes introduced in this branch ↗︎ | |
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✅ All Cypress E2E specs passed |
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Summary
Since the first commit, to activate workflows we retrieve all workflows persisted as active and loop over them to activate their webhooks, triggers and pollers, registering them as active in memory if having triggers or pollers. Later we added also populating the webhook cache if having webhooks.
Since workflow activation happens after we stand up the server, we have a race condition between user edits to a workflow's active state and the activation loop. As a result, a user-deactivated workflow can end up active when later processed by the loop. The window for this to happen is longer the more workflows the instance has to activate.
To reduce (but not eliminate) this risk, this PR skips activation of workflows that were deactivated between the start of the loop and the exact time when they are about to be activated. To eliminate this risk, we'd have to move away from the bulk activation loop entirely, which will be a larger effort.
Related Linear tickets, Github issues, and Community forum posts
https://linear.app/n8n/issue/CAT-637
Review / Merge checklist
release/backport(if the PR is an urgent fix that needs to be backported)