As part of the 3.0.0, we upgraded the mysql connector that we include to the latest available from the 1.0 line on their website (new version 1.0.9). Unfortunately, it looks like they made some big changes from 1.0.7, and have broke something with connection pooling. We got a report from a customer, and have already replicated it ourselves. I can’t say if the problem occurs all of the time, or only under certain conditions, but for some reason the connector begins to create many many connections, eventually hitting the limit. After it’s hit the limit, all connections are dropped, and the fsql groups error out.
We’ll be looking into this in more depth soon, but I wanted to let you know that we have since reverted back to the 1.0.7 build, which has worked well so far (remember the extra parameters that are posted in various places here). We were prompted to upgrade due to some problems we were having during block group testing, but we were not able to replicate those problems today.
So, until we have a solid answer, I’d recommend downloading the 3.0.1 update available now, which includes the 1.0.7 connector again (in addition to some other fixes).