Redis到期通知和烧瓶

Question

I'm trying to implement a heartbeat mechanism in Flask via redis (since I'm already using it for a bunch of other stuff already).

When a GET request is received, my Flask app sets an expirable redis variable A. Multiple GET requests resets the expiration time of A. When A truly expires, I need to modify a whole bunch of other redis variables.

Do I need to setup another redis client acting as a SUB running in the background to detect the expirations? Is there a way to do this directly in the same Flask webapp client?

Answer 1

You will need another client in background listening to the key expiration notifications. Also note that this feature is only present in Redis 2.8. So if you are using a previous version you will need to handle the notification yourself. There is a lengthy explanation about the alternatives in this StackOverflow post .