N8N Error Handling: Build Bulletproof Workflows

7-Node Production Error Handler

1. Error Trigger
   ↓
2. Function Node: Extract error details
   → Workflow name
   → Error message
   → Failed node
   → Timestamp
   → Input data
   ↓
3. Switch Node: Classify error severity
   → Critical: Payment processing, customer-facing
   → Warning: Internal reports, data sync
   → Info: Non-essential workflows
   ↓
4a. [Critical Path] PagerDuty Alert
   → Immediate page to on-call engineer
   → Include full error context
   ↓
4b. [Warning Path] Slack #alerts channel
   → Detailed error message
   → Link to workflow execution
   ↓
4c. [Info Path] Log to database
   → Error tracking table
   → No immediate alert
   ↓
5. Postgres Node: Log all errors
   → Error history for analysis
   ↓
6. Fallback Workflow (if applicable)
   → Trigger alternate data source
   → Partial success better than total failure
   ↓
7. Email Summary (daily digest)
   → All errors from past 24 hours

// Error Trigger provides this data:
{{
  "execution": {
    "id": "12345",
    "mode": "trigger",
    "startedAt": "2025-01-15T14:23:00.000Z"
  },
  "workflow": {
    "id": "67890",
    "name": "Daily Revenue Report"
  },
  "node": {
    "name": "Stripe API",
    "type": "n8n-nodes-base.stripe"
  },
  "error": {
    "message": "Request failed with status code 429",
    "description": "Rate limit exceeded",
    "context": {
      "httpCode": 429,
      "requestId": "req_abc123"
    }
  }
}}

Slack Node Message Template

🚨 **CRITICAL WORKFLOW FAILURE**

**Workflow:** {{ $json.workflow.name }}
**Failed Node:** {{ $json.node.name }}
**Error:** {{ $json.error.message }}

**Details:**
• Execution ID: {{ $json.execution.id }}
• Time: {{ DateTime.fromISO($json.execution.startedAt).toFormat('yyyy-MM-dd HH:mm:ss') }}
• Error Description: {{ $json.error.description }}

**Action Required:**
1. Check execution logs: https://n8n.yourcompany.com/execution/{{ $json.execution.id }}
2. Review error context above
3. Implement fix or trigger manual recovery

CC: @engineering-oncall

8-Node Exponential Backoff Loop

1. Manual/Webhook Trigger
   ↓
2. Set Node: Initialize retry counter
   retryCount = 0
   maxRetries = 5
   ↓
3. HTTP Request Node (API call)
   • Settings: Continue on Fail = TRUE
   ↓
4. IF Node: Check if succeeded
   → Success? Go to node 8
   → Failed? Continue to node 5
   ↓
5. Function Node: Calculate exponential delay
   const retryCount = $json.retryCount;
   const baseDelay = 1000; // 1 second
   const maxDelay = 32000; // 32 seconds
   const jitter = Math.random() * 0.4 - 0.2; // ±20%

   let delay = Math.min(
     baseDelay * Math.pow(2, retryCount),
     maxDelay
   );
   delay = delay * (1 + jitter);

   return {
     delay: Math.floor(delay),
     retryCount: retryCount + 1
   };
   ↓
6. Wait Node: Dynamic delay
   Time: {{ $json.delay }} ms
   ↓
7. IF Node: Check retry limit
   → retryCount < maxRetries? Loop back to node 3
   → retryCount >= maxRetries? Trigger error workflow
   ↓
8. Success Node: Process result

// Exponential backoff calculation with jitter
const retryCount = $json.retryCount || 0;
const baseDelay = 1000; // 1 second
const maxDelay = 32000; // 32 seconds cap
const maxRetries = 5;

// Exponential calculation: 2^retryCount
let delay = baseDelay * Math.pow(2, retryCount);

// Cap at maximum to prevent excessive waits
delay = Math.min(delay, maxDelay);

// Add jitter (±20% randomness to prevent thundering herd)
const jitterFactor = 1 + (Math.random() * 0.4 - 0.2);
delay = delay * jitterFactor;

// Check if we should retry
const shouldRetry = retryCount < maxRetries;

return {
  delay: Math.floor(delay),
  retryCount: retryCount + 1,
  shouldRetry: shouldRetry,
  message: `Retry ${retryCount + 1}/${maxRetries} after ${Math.floor(delay)}ms`
};

// Delay progression with jitter:
// Retry 1: ~1,000ms (0.8s - 1.2s)
// Retry 2: ~2,000ms (1.6s - 2.4s)
// Retry 3: ~4,000ms (3.2s - 4.8s)
// Retry 4: ~8,000ms (6.4s - 9.6s)
// Retry 5: ~16,000ms (12.8s - 19.2s)