Error Handling System with PostgreSQL Logging and Rate-Limited Notifications

This n8n workflow provides a robust system for handling errors that occur in other workflows. It logs detailed error information to a PostgreSQL database and then conditionally sends notifications, potentially with rate limiting, to prevent alert fatigue.

What it does

This workflow is designed to be triggered by errors from other n8n workflows and perform the following actions:

1. Captures Error Details: Listens for error events from any workflow configured to use this as an error workflow.
2. Logs to PostgreSQL: Inserts the captured error details (workflow name, node, error message, execution ID, etc.) into a PostgreSQL database table for persistent storage and analysis.
3. Conditional Notification: Evaluates the error to decide if a notification should be sent. This can be based on criteria such as error type, frequency, or specific keywords.
4. Rate-Limited Notifications (Implicit): Although not explicitly shown in the provided JSON, the presence of an If node and Pushover suggests the capability to implement rate-limiting logic (e.g., only notify if the same error hasn't occurred within a certain timeframe, or if the error count exceeds a threshold).
5. Sends Pushover Notification: If the conditions are met, sends a notification via Pushover to alert relevant personnel.
6. Sends Email Notification: Can also send an email notification as an alternative or additional alert mechanism.
7. Sub-workflow Execution: Includes an Execute Sub-workflow node, indicating that it can delegate certain error handling tasks to another specialized sub-workflow.

Prerequisites/Requirements

To use this workflow, you will need:

• n8n Instance: A running n8n instance.
• PostgreSQL Database: Access to a PostgreSQL database to store error logs. You'll need to configure a credential for this.
• Pushover Account: A Pushover account and API token/user key for sending mobile notifications. You'll need to configure a credential for this.
• SMTP Server (for Email): Access to an SMTP server for sending email notifications. You'll need to configure a credential for this.
• Error Workflows: Other n8n workflows configured to trigger this workflow upon failure.

Setup/Usage

1. Import the Workflow: Import this JSON into your n8n instance.
2. Configure Credentials:
   • Set up a Postgres credential with your database connection details.
   • Set up a Pushover credential with your application token and user key.
   • Set up an Email Send (SMTP) credential with your email server details.
3. Configure PostgreSQL Node (ID: 30):
   • Select your PostgreSQL credential.
   • Configure the SQL query to INSERT error details into your desired table. The error data will be available from the Error Trigger node.
     • Example table structure: errors (id SERIAL PRIMARY KEY, workflow_name VARCHAR(255), node_name VARCHAR(255), error_message TEXT, execution_id VARCHAR(255), timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP);
     • Example SQL: INSERT INTO errors (workflow_name, node_name, error_message, execution_id) VALUES ('{{ $json.workflow.name }}', '{{ $json.node.name }}', '{{ $json.error.message }}', '{{ $json.execution.id }}');
4. Configure If Node (ID: 20):
   • Define the conditions under which you want to send notifications (e.g., {{ $json.error.message }} contains "critical error", or {{ $json.error.code }} is 500).
5. Configure Pushover Node (ID: 383):
   • Select your Pushover credential.
   • Set the User Key and Message using data from the Error Trigger node (e.g., Workflow '{{ $json.workflow.name }}' failed at node '{{ $json.node.name }}' with error: {{ $json.error.message }}).
6. Configure Send Email Node (ID: 11):
   • Select your Email Send credential.
   • Set the To, Subject, and Body using data from the Error Trigger node.
7. Configure Error Workflows: In any workflow you want to monitor, go to the workflow settings and set this workflow as the "Error Workflow".
8. Activate the Workflow: Ensure this error handling workflow is active.

This setup will ensure that whenever an error occurs in a monitored workflow, the details are logged to your database, and you receive notifications based on your defined conditions. The Execute Sub-workflow node (ID: 111) and When Executed by Another Workflow trigger (ID: 837) are present, suggesting the capability to chain error handling logic into more specialized sub-workflows if needed.