Redis-cli - list of running queues command? - redis

Question

I want to see the List of queues in the Redis server using Redis-cli. I am using this command to just monitor the queue.
redis-cli MONITOR | grep queuename
Please tell me if we have the any cli comamnd which meet my requirement.

Answer 1

I don't seem to have enough reputation to clarify in a comment how you have implemented your queue, so I'll provide a few thoughts below assuming you have your queue implemented as a FIFO queue using RPUSH and LPOP to add and remove items from your queue.
> RPUSH queue-1 "task-a"
(integer) 1
>LPOP queue-1
"task-a"
If you use a standard naming convention for your lists that represent queues, you could get them by name from the KEYS command with something like KEYS queue-*. A couple of notes on this approach. First, this has some performance concerns if you have a large number of keys in your production instance the best use is for ad-hoc troubleshooting when the rest of your team is aware there may be some performance hit to your redis instance. Second, this will only show keys where the list contains elements. If you have drained a queue it will not appear in the returned values.
An alternative using sorted sets to hold the keys for the lists used as queues, and modifying the score associated with the queue to give you an idea of the queue size. When adding or removing a message to a queue, you would also use ZADD to increment the score by the number of elements added or returned. This would allow you to quickly get the set of lists used as queues by decreasing queue size with ZREVRANGE at any point.
> RPUSH queue-1 "task-a"
(integer) 1
> ZADD queues INCR 1 queue-1
"1"
> RPUSH queue-1 "task-b"
(integer) 2
> ZADD queues INCR 1 queue-1
"2"
> RPUSH queue-2 "message-a"
(integer) 1
> ZADD queues INCR 1 queue-2
"1"
> RPUSH queue-2 "message-b"
(integer) 2
> ZADD queues INCR 1 queue-2
"2"
> LPOP queue-2
"message-a"
> ZADD queues INCR -1 queue-2
"1"
> ZREVRANGE queues 0 -1 WITHSCORES
1) "queue-1"
2) "2"
3) "queue-2"
4) "1"