[Users] CDR capturing

Hello, I was wondering if users out there would be willing to share what mechanism they have found success with in regards to capturing cdrs at a high rate. We recently ran into some problems writing CDRs to a postgres database. Openser threads seemed to block which led to incoming messages not being processed in a timely manner. Flatstore solved the problem but created others, primarily how to stream the data off box for real time processing. We are considering Mysql but first wanted to ask the community to weigh in on what is considered 'best practice' for cdr/transaction record capturing. Our goal is to handle 500 CPS without lost records or process blocking. Thanks. Tim