[Catalyst] Sharing session and login data

[Perrin Harkins]

On 2/28/07, Jeffrey Ng <jeffreyn at gmail.com> wrote:
> we have just improved our session implementation. instead of storing
> our session table in mysql database, we stored them in memcache.

Memcached does things like silently drop your data when it runs out of
room.  If the daemon stops for any reason, all of your sessions are
instantly gone (unlike a database where they are safely on disk and
you can restart it).  It is designed to be unreliable storage, since
it's a cache and not a database.

Some sites can get away with it, because they just don't care if they
use all their users' sessions.  Just be sure that your site is one of
those before your start putting your sessions into lossy storage.

- Perrin