Skip to main contentWhiskyPay Workers
WhiskyPay Workers is a background job processing system that handles asynchronous tasks related to payment processing. Built with BullMQ and Redis, it ensures reliable execution of critical post-payment operations.
Purpose
The Workers system serves two primary purposes:
- Webhook Delivery: Reliably notifying merchants about successful payments through webhook callbacks
- Email Notifications: Sending confirmation emails to both buyers and merchants
By handling these operations asynchronously, the main payment flow remains fast and responsive, while ensuring that notifications are delivered reliably even in the case of temporary failures.
Key Features
- Queue-based Architecture: Uses Redis and BullMQ for durable message queuing
- Automatic Retries: Failed jobs are automatically retried with exponential backoff
- Error Handling: Comprehensive error logging and notification
- Separate Queues: Different queues for webhook callbacks and emails
- Scalable Design: Can be scaled horizontally for high-volume processing
System Components
1. Queue Management
The worker system uses BullMQ, a Redis-based queue for Node.js, to manage job processing:
callbackQueue: For webhook notifications to merchantsemailQueue: For sending email confirmations
2. Job Processors
Each queue has a dedicated worker that processes jobs:
- Callback Worker: Makes HTTP requests to merchant-defined endpoints
- Email Worker: Sends formatted emails using nodemailer
3. Infrastructure
The system relies on:
- Redis: For storing and managing job queues
- Node.js: Runtime environment for job processing
- nodemailer: For handling email delivery
Job Flow
- Job Creation: When a payment is successfully verified, the Payment Gateway adds jobs to the appropriate queues
- Job Queuing: Jobs are stored in Redis with metadata about the task
- Worker Processing: Background workers pick up jobs from their respective queues
- Task Execution: The worker executes the task (HTTP request or email sending)
- Result Handling: Success is logged, or the job is retried on failure
Benefits
- Reliability: Ensures notifications are delivered even if the first attempt fails
- Scalability: Handles any volume of notifications without impacting core payment processing
- Durability: Jobs persist even if workers crash or restart
- Monitoring: Provides insights into notification delivery and failures
Use Cases
Webhook Notifications
- SaaS applications update user subscription status
- E-commerce systems update order status
- CRM systems track customer purchases
- Analytics platforms record payment events
Email Notifications
- Send purchase receipts to customers
- Notify merchants of new sales
- Send welcome emails for new subscriptions
- Provide payment confirmations with details
Next Steps
