Which is faster/better for caching, File System or Memcached?

Question

I don\'t think it\'s clear to me yet, is it faster to read things from a file or from memcached? Why?

Answer 1

"Faster" can not be used without context. For example, accessing data in memcached on remote server can be "slower" due to network latency. In the other hand, reading data from remote server memory via 10Gb network can be "faster" than reading same data from local disk.

The main difference between caching on the filesystem and using memcached is that memcached is a complete caching solution. So there is LRU lists, expiration concept (data freshness), some high-level operations, like cas/inc/dec/append/prepend/replace.

Memcached is easy to deploy and monitor (how can we distinguish "cache" workload on filesystem from, let's say kernel? Can we calculate total amount of cached data? Data distribution? Capacity planning? And so on).

There are also some hybrid systems, like cachelot Basically, it's memcached that can be embedded right into the application, so the cache would be accessible without any syscalls or network IO.