Another update: Note: I kept dev@roller on CC, which was added by Dave.
After a couple of hours we did run into a memory issue (tenured full, CMS running pauseless). I took a memory dump and increased heap size, because I had already noticed it was a bit tight.
Roller did not start then, because it was blocked/banned by the mysql server for to many connection errors. I flushed the block in the mysql server (and added logging there) and roller did start.
I switched roller back to using the container provided jdbc pool, but based on dbcp, no eviction, no auto reconnect.
Maybe the memory issues and the mysql connection errors are related one or the other way, I didn't yet find the time to check, which of both might have started earlier.
Regards, Rainer