That has been false for 4 years.
https://github.com/resque/resque-scheduler/blob/master/lib/r...
https://github.com/resque/resque-scheduler/blob/master/lib/r...
Resque will scan for set value with key prefix like "timestamps:" or "delayed:", for every five seconds, if there's any task queued it will be fired.
There's many pros/cons with this approach, e.g. in Redis SADD, SMEMBERS are O(N) operations while in theory dedicated cron algorithm could make O(log(n)).
https://en.wikipedia.org/wiki/Cron#Multi-user_capability
This is is important if you have many short lived, timestamp based events need to handle. My use case is design item cool down for a mobile/web game using server side push, with millions of users. While resque could in theory solve this problem, but it's no different from a per 5 minute crontab command.
So anyway, what I hope is a native clock in Redis handling all this.
Specifically about "cron" capability, resque-scheduler does a pretty good job for Resque in general. Resque Bus uses it for exponential-backoff retry.
It uses the scheduling capability for the "Heartbeat" described in the README. I'll write more about that later if people are interested. Quickly, it's an automated way to add events every minute. We use this like a global (shared across applications and servers) cron clock.
Currently all redis-based background job implementations does not support scheduled jobs.
Redis is not only a memcache replacement, but also a good data structure server, as central hub I hope it add more time-sturcture functions.