cache full

Hello,
lately after a few days the redis cache “stop” working. the backend became extremely slow. It’s seem like the cache memory is full. The flush button disappear
https://tinyurl.com/y2j867l5
After running the command: redis-cli FLUSHALL, everything’s back to normal

How can I solve this? Increase the buffer or flush the redis cache automatedly every 2-3 days (maybe with cron job)?

Thanks
Ricky