Over the last few weeks I have been doing some work on improving
the concurrency performance of PBXT. The last Alpha version (1.0.03) has
quite a few problems in this area.
Most of the problems have been with r/w lock and mutex contention but, I soon discovered that MySQL has some serious problems of it's own. In fact, I had to remove some of the bottlenecks in MySQL in order to continue the optimization of PBXT.
The result for simple SELECT performance is shown in the graph below.