[Building Sakai] performance issues

[Hedrick Charles]

We're now in our period of peak usage. Response is somewhat slow in some areas, though the system itself is OK. The issue seems to be primarily for the main page in assignments at the moment, but Samigo's main page has also been a problem. 

I understand why it's nice to give the user a summary of their assignments or tests, but these summary pages are a bit load issue. They get data and check permission for each object. With hundreds of people trying to bring these pages up at the same time, it's just too much. I'd like to see some work done on just those two pages, to optimize them.

Our database server is currently processing a bit over 100 queries at any given time right  now, at least half of which are permission checks (i.e. checks on the realm table). A fairly small number of queries represents a very large part of the total. This sound like a job for more intelligent caching, or even memcached.