On: Salvatore Sanfilippo talks Redis design and internals

[SebMueller]

How can I scale redis Pub/Sub system when I need more messages/second?

[antirez → SebMueller]

Pub/Sub is receiver-intensive, not publish-intensive, so basically if you have many subscribers the best thing you can do is to setup a few slaves.

PUBLISH commands are propagated on slaves. So you can attach your subscribers in a random slave.

Another approach is, if you don't have any pattern matching subscriber, to shard based on the hash of the key.