How to implement cache expiration mechanism in Redis?

6 months ago

2 minutes

In Redis, the cache expiration mechanism can be implemented by setting a time to live (TTL). You can use the EXPIRE command to set the expiration time for a specific key, and when the time is reached, Redis will automatically delete that key. For example:

SET mykey "hello"
EXPIRE mykey 60

The above command sets the value of the key “mykey” to “hello” and also sets an expiration time of 60 seconds. After 60 seconds, Redis will automatically delete the key “mykey”.

Additionally, you can use the TTL command to check the remaining expiration time of a specific key. For example:

TTL mykey

This allows you to check the remaining expiration time of the mykey key. If returned -2, it means the key does not exist; if returned -1, it means the key has no expiration time set; other positive integers represent the expiration time in seconds.

By setting appropriate expiration times, it is possible to implement a cache invalidation mechanism to maintain the freshness and validity of cached data.