[SR-Users] authentification issue when nb user increase

Hello, I have a proxy with Kamailio 5.0.6 working since few month without any issue. Around 4500 locations and 5300 contacts This weekend we move a very old proxy (Kamailio 3.3.2 with an old server )to this new one, adding around 14’000 users and 15’000 contacts. Yesterday when calls was starting we get an big issue with this new proxy, lot of phones was disconnected and some calls was rejected. I see that the issue was the authentication (done via a mysql DB with the cluster db module) many phone get a failure and was disconnected, mostly phone connected via TCP or TLS we see less issue with UDP even we have much more . The issue was not the number of TCP/TLS connection as we see the REGISTER and the 401 going back, so connection was correctly done Currently it’s working but I don’t know exactly why ☹, I mean I have done a change but it has really no relation … , during the same time I get another issue, some calls have no voice… We are using rtpengine (on the old proxy we was using rtpproxy) and with the rtproxy we already face a long time ago such case and to solve it we setup multiple rtpproxy (on the same host) So I try to do the same, I setup a second rtpengine on the same host and when I reload the config with : kamcmd rtpengine.reload all registration was working perfectly ... As they is no relation with the registration end the rtpengine I don't know why now it's working. Any idea ? BR Laurent