Concurrency Lock Release [apm]Install

Overview

This node releases a concurrency lock for a specific workflow by deleting a corresponding key in a Redis database. It is useful in scenarios where workflows are limited to run concurrently, and you want to manually or programmatically release the lock to allow new executions. For example, if a workflow execution was interrupted or stuck, this node can clear the lock so that subsequent executions are not blocked.

Properties

Output

The node outputs a JSON object with the following structure:

{
  "workflowId": "<the workflow ID provided>",
  "lastUpdate": null
}

• workflowId: The ID of the workflow for which the lock was released.
• lastUpdate: Always null here, indicating no timestamp is returned after deletion.

No binary data is output by this node.

Dependencies

• Requires a Redis server accessible with credentials (host, port, password).
• The node expects an API key credential or similar authentication to connect to Redis.
• Configuration of Redis credentials must be done in n8n prior to using this node.

Troubleshooting

• Missing Redis Credentials: If Redis credentials are not configured or missing, the node will throw an error stating "Redis credentials are missing". Ensure credentials are properly set up in n8n.
• Empty Workflow ID or Namespace: The node validates that both the workflow ID and namespace are non-empty strings. If either is empty, it throws an error indicating the respective field cannot be empty.
• Connection Issues: If the node cannot connect to Redis (due to network issues, wrong host/port, or authentication failure), it may time out or fail. Verify Redis server availability and credentials.
• Lock Not Found: If the lock key does not exist in Redis, the node still completes successfully since deleting a non-existent key is harmless.

Links and References

• Redis DEL command documentation
• ioredis GitHub repository
• n8n Documentation - Creating Custom Nodes