Streaming¶

Redis Streams give consumer groups, persistence, and approximate ordering per shard. Astra uses them for task dispatch and worker events. Compare to Kafka when you need longer retention, replay-by-offset, and cross-datacenter replication — Redis wins for low-latency work queues with modest retention.

At-least-once: consumers must idempotent handlers or dedupe by message ID. Task execution uses DB state to reject duplicate completes.