Is there a way to increase ttl in redis?

Question

我知道有几种方法可以为键设置特定的 ttl，但是有没有办法为具有倒计时 ttl 的键添加一些额外的时间？

Answer 1

There's no built-in way to extend TTL. You need to get the current TTL, and then add some more TTL to it.

Wrap these two steps into a Lua script:

-- extend 300 seconds
eval 'local ttl = redis.call("TTL", "key") + 300; redis.call("EXPIRE", "key", ttl)' 0

Answer 2

1. Good question
2. there is no such command
3. I think it is a bad idea to have a command like that, you have to be careful when you use it.
4. Probably end up adding more time to the ttl than we expect. If you set it like 5 mins, the actual expire time will be close to 5 mins even if setting it multiple times in that request. But if you add multiple 5 mins to it, then we can`t be sure of the actual expire time