redis 數據淘汰策略
volatile-lru:從已設置過期的數據集中挑選最近最少使用的淘汰
volatile-ttr:從已設置過期的數據集中挑選將要過期的數據淘汰
volatile-random:從已設置過期的數據集中任意挑選數據淘汰
allkeys-lru:從數據集中挑選最近最少使用的數據淘汰
allkeys-random:從數據集中任意挑選數據淘汰
noenviction:禁止淘汰數據
redis淘汰數據時還會同步到aof中、從機
配置文件
# maxmemory <bytes>
# volatile-lru -> remove the key with an expire set using an LRU algorithm
# allkeys-lru -> remove any key according to the LRU algorithm
# volatile-random -> remove a random key with an expire set
# allkeys-random -> remove a random key, any key
# volatile-ttl -> remove the key with the nearest expire time (minor TTL)
# noeviction -> don't expire at all, just return an error on write operations
# The default is:
# maxmemory-policy noeviction
我們可以設置maxmemory <bytes>，當數據達到限定大小后，會選擇配置的策略淘汰數據