Course/Chapter 9/1. Reading Execution Logs
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    Chapter 9: Troubleshooting & Debugging

    1. Reading Execution Logs

    Navigate the execution history to find issues.

    15m Lesson 1 of 5

    The execution log is your primary debugging tool. Every workflow run is recorded with full input/output data at each node.

    Key Information

    • - Execution status: Success, Error, or Running
    • - Node-level data: Input and output for each node
    • - Error details: Error message, stack trace, and failed node
    • - Timing: How long each node took to execute

    Navigating the Execution Log

    1. Open the Executions tab in the sidebar
    2. Filter by status: All, Success, Error, Running
    3. Click an execution to see the full node-by-node breakdown
    4. Click any node to inspect its input and output data
    5. Use the timeline view to see execution order and duration

    Debugging Workflow

    1. Find the failed execution in the log
    2. Click the red node (the one that failed)
    3. Read the error message — it usually tells you exactly what went wrong
    4. Check the input data — is the node receiving what you expect?
    5. Fix the issue and re-execute

    Code Examples

    Common Execution Log Patterns
    text
    ✅ SUCCESS — All nodes green
   → Workflow completed normally

❌ ERROR at "HTTP Request" — 401 Unauthorized
   → Check credentials, API key may have expired

❌ ERROR at "Set" — Cannot read property 'email' of undefined
   → Previous node returned empty/unexpected data

⚠️ SUCCESS with warnings — Some items failed
   → "Continue on Fail" caught errors, check error output

🔄 RUNNING (stuck) — Execution hasn't completed
   → Check for infinite loops or hung API calls

    Pro Tips

    • 💡Click on any node in a failed execution to see exactly what data it received and what went wrong
    • 💡Use the execution filter to quickly find recent failures
    • 💡Enable "Save Successful Executions" during development to debug data flow issues

    Comprehension Quiz

    Answer 2 of 2 correctly to unlock lesson completion.

    1. What is the primary debugging tool in n8n?

    2. What should you check first when a node fails?

    Pass the quiz above to unlock lesson completion
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    All lessons in this chapter

    1. Reading Execution Logs15m2. Common Errors & Fixes15m3. Advanced Error Handling15m4. Monitoring & Alerting15m5. Performance Optimization15m