How is Redis used in Trello?

Question

I understand that, roughly speaking, Trello uses Redis for a transient data store.

Is anyone able to elaborate further on the part it plays in the application?

Answer 1

Trello uses Redis with Socket.IO (RedisStore) for scaling, with the following two features:

• key-value store, to set and get values for a connected client
• as a pub-sub service

Resources:

Look at the code for RedisStore in Socket.IO here: https://github.com/LearnBoost/socket.io/blob/master/lib/stores/redis.js

Example of Socket.IO with RedisStore: http://www.ranu.com.ar/2011/11/redisstore-and-rooms-with-socketio.html