redis cache clearing strategy

1. volatile-lru: Use LRU algorithm to remove keys, only for keys with expiration time set

2. allkeys-lru: use LRU algorithm to remove keys

3. volatile-random: remove random keys from the expired set, only for keys with an expiration time set

4. allkeys-random: remove random keys

5. volitile-ttl: remove the keys with the smallest ttl value, that is, those keys that will expire recently

6. noevicate: do not remove, only return error information for write operations