Hi guys, I was wondering if memcached frees up unused ram after it expires or if it just keeps using the ram in there but invalidates the key.
Im hearing from people that it does free up the ram when caches expire, but the behavior that we see on our site is this. Here's the pattern I've been seeing with the memcached. Memcached for us doesnt seem to release memory, it just keeps growing until eventually slowness shows up on our site and then we are required restart the memcached instances and mongrels afterwards because newrelic starts showing that memcached reads are slow. The reason I think that memcached doesnt release memory for us is that it takes us about a week before the 1GB memcached on a slice gets full and our longest expire is 6 hours... When we start up our memcached servers and leave them running, they dont get full right away. It takes them about 1 week to eventually get full and run out of RAM. Our highest expiry is 6 hours, so memcached should free space up after that. So, since the memcached doesnt gets full within 6 hours it seems like memcached isnt freeing up the expired caches.. If it did get full within 6 hours, then obviously we need to allocate more RAM. Thanks in advance for any responses, Tung
