BE-038 — Implement Background Job Scheduler & Worker System
📚 Overview
The Background Job Scheduler & Worker System is responsible for executing asynchronous tasks across the TruthBounty backend. Rather than performing long-running operations during API requests, jobs are queued and processed independently by dedicated workers.
This service forms the execution backbone for notifications, event processing, analytics aggregation, cache warming, report generation, blockchain synchronisation, retry mechanisms, scheduled maintenance, and future AI workloads.
The scheduler must be horizontally scalable, fault tolerant, observable, and capable of processing thousands of concurrent jobs.
🧠 Background
Many backend operations should not execute during an HTTP request because they:
- take several seconds
- depend on external services
- may fail temporarily
- require retries
- are CPU intensive
- involve large datasets
Examples include:
- email delivery
- notification dispatch
- webhook retries
- blockchain indexing
- analytics aggregation
- cache rebuilding
- reputation recalculation
- report generation
Without a dedicated job processing system, API latency increases dramatically while overall system reliability decreases.
The Worker System enables asynchronous execution while maintaining high API responsiveness.
🎯 Objectives
Implement a distributed background processing platform that:
- schedules delayed jobs
- processes queued jobs
- retries failed jobs
- supports recurring tasks
- scales horizontally
- guarantees job durability
- provides monitoring
- supports prioritisation
🧩 Technical Scope
1. Queue Infrastructure
Implement queue support using Redis.
Support:
- multiple queues
- persistent jobs
- delayed jobs
- scheduled jobs
- recurring jobs
- priority queues
2. Worker Processes
Implement dedicated workers for:
- Notifications
- Webhooks
- Blockchain Events
- Analytics
- Reports
- Cache Management
- Reputation Updates
- AI Processing
- Scheduled Maintenance
Workers must run independently from the API.
3. Job Priorities
Support priority levels:
Higher-priority jobs must execute before lower-priority jobs.
4. Retry Policies
Implement automatic retries with:
- exponential backoff
- retry limits
- configurable delays
- retry logging
- dead-letter queue
5. Scheduled Jobs
Support cron-based execution for:
- cache cleanup
- report generation
- analytics aggregation
- health checks
- leaderboard rebuilding
- governance maintenance
- blockchain reconciliation
6. Dead Letter Queue
Failed jobs exceeding retry limits should be moved into a Dead Letter Queue (DLQ).
Support:
- inspection
- replay
- deletion
- diagnostics
- failure categorisation
7. Job Monitoring
Track:
- queued jobs
- active jobs
- completed jobs
- failed jobs
- retry count
- execution duration
- queue depth
- worker utilisation
8. Worker Scaling
Support:
- multiple worker instances
- horizontal scaling
- graceful shutdown
- automatic recovery
- workload balancing
9. Administrative APIs
Provide APIs for:
- queue inspection
- job lookup
- replay failed jobs
- cancel jobs
- retry jobs
- worker status
- scheduler status
10. Future Extensibility
Design the scheduler to support:
- distributed orchestration
- workflow pipelines
- AI task execution
- event-driven processing
- cross-service job routing
- cloud-native schedulers
✅ Acceptance Criteria
- Jobs execute asynchronously.
- Scheduled jobs run correctly.
- Retry logic functions.
- Dead Letter Queue operates correctly.
- Worker scaling is supported.
- Monitoring metrics are available.
- Administrative APIs function correctly.
- Integration tests pass.
🧪 Testing Requirements
Implement tests covering:
- queue operations
- delayed jobs
- recurring jobs
- retries
- worker failures
- dead-letter queue
- concurrent execution
- worker scaling
- monitoring
Coverage target: 90%+
📚 Documentation
Update:
- Backend Architecture
- Operations Manual
- Queue Configuration Guide
- Scheduler Documentation
- API Documentation
- Deployment Guide
🔗 Dependencies
Depends on:
- BE-021 — Implement Redis Cache & Distributed Session Management
- BE-025 — Implement Webhook Management Service
- BE-027 — Implement API Usage Analytics Service
Blocks:
- Notification Service
- Blockchain Indexer
- Analytics Pipeline
- AI Processing
- Scheduled Maintenance
- Report Generation
🏷 Labels
- backend
- infrastructure
- architecture
- scalability
- complexity-high
- stellar-wave
📊 Complexity
High
This service underpins nearly every asynchronous workflow in TruthBounty. It must provide reliable execution, fault tolerance, observability, and scalability while ensuring no critical background tasks are lost.
⏱ Estimated Effort
6–8 days
🚀 Definition of Done
- Queue infrastructure implemented.
- Worker processes operational.
- Priority scheduling functioning.
- Retry mechanisms implemented.
- Dead Letter Queue operational.
- Scheduled jobs supported.
- Monitoring metrics available.
- Administrative APIs completed.
- Tests passing.
- Documentation updated.
- Ready for integration with Notification Service, Blockchain Indexer, Analytics Pipeline, AI Processing, Scheduled Maintenance, and Report Generation.
BE-038 — Implement Background Job Scheduler & Worker System
📚 Overview
The Background Job Scheduler & Worker System is responsible for executing asynchronous tasks across the TruthBounty backend. Rather than performing long-running operations during API requests, jobs are queued and processed independently by dedicated workers.
This service forms the execution backbone for notifications, event processing, analytics aggregation, cache warming, report generation, blockchain synchronisation, retry mechanisms, scheduled maintenance, and future AI workloads.
The scheduler must be horizontally scalable, fault tolerant, observable, and capable of processing thousands of concurrent jobs.
🧠 Background
Many backend operations should not execute during an HTTP request because they:
Examples include:
Without a dedicated job processing system, API latency increases dramatically while overall system reliability decreases.
The Worker System enables asynchronous execution while maintaining high API responsiveness.
🎯 Objectives
Implement a distributed background processing platform that:
🧩 Technical Scope
1. Queue Infrastructure
Implement queue support using Redis.
Support:
2. Worker Processes
Implement dedicated workers for:
Workers must run independently from the API.
3. Job Priorities
Support priority levels:
Higher-priority jobs must execute before lower-priority jobs.
4. Retry Policies
Implement automatic retries with:
5. Scheduled Jobs
Support cron-based execution for:
6. Dead Letter Queue
Failed jobs exceeding retry limits should be moved into a Dead Letter Queue (DLQ).
Support:
7. Job Monitoring
Track:
8. Worker Scaling
Support:
9. Administrative APIs
Provide APIs for:
10. Future Extensibility
Design the scheduler to support:
✅ Acceptance Criteria
🧪 Testing Requirements
Implement tests covering:
Coverage target: 90%+
📚 Documentation
Update:
🔗 Dependencies
Depends on:
Blocks:
🏷 Labels
📊 Complexity
High
This service underpins nearly every asynchronous workflow in TruthBounty. It must provide reliable execution, fault tolerance, observability, and scalability while ensuring no critical background tasks are lost.
⏱ Estimated Effort
6–8 days
🚀 Definition of Done