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Database / REDIS

Which is better and why: Redis Pub/Sub or Redis Streams for event delivery?

The two solve overlapping but genuinely different problems, so "better" depends entirely on whether message durability and replay matter for the use case.

Pub/Sub is the better fit when messages are only meaningful to clients that are connected right now — live dashboards, real-time notifications, chat presence updates — where a message missed by a disconnected client is expected to simply be irrelevant by the time that client reconnects. It's simpler, has lower overhead, and needs no consumer-group bookkeeping.

Streams is the better fit whenever a message must not be silently lost if no one happens to be listening at that exact instant — event sourcing, audit logs, task queues, or any pipeline where a consumer restarting or briefly disconnecting shouldn't mean lost data. Streams' persistence, consumer groups, and per-message acknowledgment give it delivery guarantees Pub/Sub fundamentally doesn't attempt to provide.

The practical rule: reach for Pub/Sub when "only currently-listening clients need this" is actually true and acceptable; reach for Streams the moment reliable delivery, replay, or coordinated processing across multiple consumers becomes a real requirement rather than a nice-to-have.

When is Pub/Sub the better choice over Streams?
What does Streams offer that Pub/Sub fundamentally does not?

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