As per: http://opensips.org/pipermail/users/2011-June/018238.html I am opening a bug report. We need to use db_mode =3 as when using others there ends up being issues with our mysql master/master replication.
Maybe it is a configuration issues, so I have some questions for you:
- how much private mem have you set ?
- how many records do you have in usrloc ?
Also, you may try using multiple pinger processes in nathelper:
this will reduce the mem usage per timer process.