I solved a distributed queue problem after 15 years
6 days ago
- #task queues
- #Postgres
- #distributed systems
- RabbitMQ was a critical message broker at Reddit, handling tasks like upvotes before database writes.
- Task queues provided horizontal scalability, flow control, and scheduling capabilities.
- System vulnerabilities included data loss during crashes of databases, caches, or queue processors.
- Durable queues, using persistent stores like Postgres, offer checkpointing to resume failed tasks and prevent data loss.
- Durable queues combine task queues with durable workflows, ensuring reliable orchestration of parallel tasks.
- Workflows in durable queues are checkpointed, allowing recovery from the last completed step after failures.
- Built-in observability in durable queues enables easy monitoring via SQL queries on workflow and task records.
- Durable queues are best for lower volumes of critical tasks, while traditional queues suit high volumes of smaller tasks.
- Examples of durable queue implementations include migrations from Celery to DBOS and genomic data pipelines.