Memory fragmentation isn't an issue with memcached like it is for Redis. Given enough uptime and object churn, redis will use all the memory on a server and tri

Memory fragmentation isn't an issue with memcached like it is for Redis. Given enough uptime and object churn, redis will use all the memory on a server and trigger OOM's. This is because redis counts the total amount of memory used to store objects for its "max memory" limit. With enough object churn, boom. Memcached uses its max memory configuration parameter to decide how much memory to allocate, and that's it. System memory usage never budges. Basically it boils down to fragmentation vs slab allocator model, and I'll take slabs for stability.