After a quick look to db_mysql module I spotted and issue when handling urls with groups.
A char wwas replaced with 0 inside the url, which could be the reason to get more
connection, as another check with same url won't match it.
I pushed a patch to master branch, if you test and all is ok, you can go ahead and
backport.
---
Reply to this email directly or view it on GitHub:
https://github.com/kamailio/kamailio/issues/58#issuecomment-72176732