I am experiencing a very strange case happen in production with redis, a large amount of redis keys are evicted unexpectedly even though memory not reach max configuration.
Current redis setting is max mem = 7GB, volatile-ttl. Most of the keys are set a TTL when store to Redis.
Below graph showing a large drop in redis key eventhough memory at the time was only 3.5GB (<< 7GB)
According to my understanding, Redis would evict keys only when memory reach max-mem. And even when it does, it will only drop keys gradually according to the need for inserting new keys.
Thank you very much!