add pubsub command:

[hayksaakian]

See:

http://redis.io/commands/pubsub

In my use case I would use it to count the number of active connections to a channel

PUBSUB NUMSUB $channels

[hagsteel]

The tornado-redis only have one subscriber to a channel and all the subscribers in your application belongs to that.

So redis would say you only have one subscriber.

If you look here:
https://github.com/leporo/tornado-redis/blob/master/tornadoredis/pubsub.py#L26

You see that as a new subscriber is added, it is actually added to a list rather than to redis.

You could count the number of subscribers in the list, however if you run multiple instances (load balancing and using multiple cores etc.) then the number would be inaccurate as you would only count the number of subscribers for that particular instance.

I did a basic online counter by doing a redis increment on a key every time someone connected, and decrement when they disconnected.