Don't know Redis? Think Memcache, with support for for lists, and disk-based storage. You can use Redis as a database, queue, cache server or all of those combined. Let's see how you can use this power in your PHP apps. About those disks. Well, Redis keeps the entire dataset in memory, so it's still crazy fast: 110000 SETs/second, 81000 GETs/second. Good enough for to you? "..and from time to time