One of the great difficulties of Facebook application development is the difficulty in running large-scale tests due to the large number of Facebook accounts required, and the Facebook Terms of Use which does not allow automated systems to access the Facebook servers. These issues are explained in depth in Load testing Facebook apps (Part 1) and Load testing Facebook apps (Part 2). FriendRunner acts as a drop-in replacement for the Facebook servers, and so allows you to run your tests with as many users as you'd like. Furthermore, FriendRunner's automated test system runs the entire test for you once you create a test script to define the actions for a single user.
Have you ever wondered how optimized your Memcached installation is? There is a common misconception that one doesn't have to think too deeply about Memcached performance, but that is not true. If your setup is inefficient, you could:
* Burn Memory
* Waste Network Round-Trips
* Store Keys That Never Get Retrieved
* Have a Low Cache Hit Ratio (i.e. query MySQL too much)
* Suffer a fate too horrible to contemplate.Percona does a lot of consulting around Memcached, so we try to take a quantitative, scientific approach to measuring memcached performance, just like everything else we do.
