Hello, I started do use WeBWorK this semester. It is wonderful tool.
However, as I understand, there are problems with server load during quizzes. Is it possible to implement some caching? And does it help? I once developed webpage which needed many computations (Mathematical Assistant on Web, was quite popular in my country, but does not exist aymore). I used the database where I stored md5 sum of a request and the answer. Thus it was possible to start the computation only if there was not a corresponding item in the database. This reduced the server load a lot.
Using the cache it should be possible to render the problems for each student a day before the quizzes start and this could help to reduce the server load during exam. However, I am not sure, if the bottleneck is the time required to render the problem from pg to html or something else.