The data eviction policy of a database controls what happens when new data exceeds the memory size of a database. Typically, such situations require evicting (or deleting) data previously added to the database.

To control this behavior, change the Data eviction policy setting for a database.

Available policies

For each database, you can choose from these data eviction policies:

Available policies Description
allkeys-lru Keeps most recently used keys; removes least recently used (LRU) keys
allkeys-lfu Keeps frequently used keys; removes least frequently used (LFU) keys
allkeys-random Randomly removes keys
volatile-lru Removes least recently used keys with expire field set to true (Default)
volatile-lfu Removes least frequently used keys with expire field set to true
volatile-random Randomly removes keys with expire field set to true
volatile-ttl Removes least frequently used keys with expire field set to true and the shortest remaining time-to-live (TTL) value
no eviction New values aren’t saved when memory limit is reached

When a database uses replication, this applies to the primary database

Redis Cloud supports Redis on Flash (RoF) to prevent data eviction but maintain high performance.

RoF can extend your database across RAM and Flash Memory and intelligently manage “hot” (active) data in RAM and “cold” (less active) data in Flash memory (SSD).

Note:
Active-Active databases always operates in noeviction mode.