memcached expiration time

Question

Memcached provides a cache expiration time option, which specifies how long objects are retained in the cache. Assuming all writes are through the cache I f

Answer 1

Some data in cache is expensive to create but small (should last a long time) and some is large but relatively cheap (should last a shorter time)

Also, for most applications it is hard to make memcached work as a write through cache. It is difficult to properly invalidate all caches, especially those of rendered pages. Most users will miss a couple.