Request Lifecycle

Detailed visualization of how API requests are processed through Appizer's system.infrastructure.

Complete Request Flow

Request Phases

1. Authentication

Every request must include a valid API key:

headers: {
  'Authorization': 'Bearer sk_live_abc123...',
  'Content-Type': 'application/json'
}

2. Validation

Request payload is validated against schema:

Checks performed:

• Required fields present
• Data types correct
• Values within allowed ranges
• Payload size within limits

// Validation rules
{
  event: { type: 'string', required: true, maxLength: 100 },
  userId: { type: 'string', required: false, maxLength: 255 },
  properties: { type: 'object', required: false, maxSize: 10000 }
}

3. Rate Limiting

Requests are checked against rate limits:

Default limits:

• 1000 requests per minute
• 10,000 events per hour
• Burst capacity: 100 requests

4. Queueing

Valid requests are queued for async processing:

// Queue message format
{
  id: 'msg_abc123',
  timestamp: '2024-01-15T10:30:00Z',
  payload: {
    event: 'purchase_completed',
    userId: 'user_123',
    properties: { amount: 99.99 }
  },
  metadata: {
    apiKey: 'sk_***',
    ip: '192.168.1.1',
    userAgent: 'Mozilla/5.0...'
  }
}

5. Processing

Events are processed asynchronously:

6. Response

Client receives immediate acknowledgment:

{
  "success": true,
  "eventId": "evt_abc123",
  "timestamp": "2024-01-15T10:30:00Z"
}

Error Handling Flow

Performance Characteristics

Latency Breakdown

Throughput

• Single event: 1,000 requests/sec
• Batch events: 25,000 events/sec
• Peak capacity: 100,000 events/sec

Retry Logic

Failed requests are automatically retried:

Retry configuration:

• Max retries: 4
• Initial delay: 1 second
• Backoff multiplier: 2x
• Max delay: 60 seconds
• Jitter: ±20%

Monitoring

Track request lifecycle metrics:

// Metrics collected
{
  requestId: 'req_abc123',
  phases: {
    authentication: { duration: 8, status: 'success' },
    validation: { duration: 3, status: 'success' },
    rateLimiting: { duration: 1, status: 'success' },
    queueing: { duration: 7, status: 'success' },
    processing: { duration: 85, status: 'success' }
  },
  totalDuration: 104,
  status: 'completed'
}

Best Practices

Client-Side

1. Implement timeouts: Don't wait indefinitely
2. Handle 202 responses: Request accepted, processing async
3. Retry on failures: Use exponential backoff
4. Batch when possible: Reduce request overhead

Server-Side

1. Validate before sending: Catch errors early
2. Use idempotency keys: Prevent duplicates
3. Monitor latency: Track performance
4. Log request IDs: Aid debugging

Next Steps