qmail / relaylock Problem

[Gorgoroth]

Hello everybody!

Using SuSE 9.3 with Plesk 8.2.1 - upon booting the Server, all seems to work normally - shortly (really shortly) afterwards, Ples frontent dies with "too many SQL connections, SQL server unreachable".

On the console, ps -A yields hundreds of "relaylock" processes. They add up by the dozen per second and after a few minutes the server freezes completely.

Disabling qmail in smtp_psa in xinetd.d makes it run stable, mysql works like a dream then as well as any other application.

Does anyone have a clue for me on how to fix that?

Thanks a lot!

 

[jwdick]

A "relaylock" is an ip connection to your mail server. Try limiting ip connections to 1 per ip address. Then the offending sending server must release the first "relaylock" before trying to send again.

 

[Gorgoroth]

Ok, will give that a try... also: why is the server running normally for well over 600 days and suddenly it freezes with this (reproducable) problem?

 

[jwdick]

I'm not convinced that the problem is with your server unless you know for sure that one or two ip addresses is not causing multiple locks. About a month ago, I had 4 ip addresses hitting my server with over 500 connections at any given time from each separate ip. Combine that with the normal connections it almost knocked my server to it's knees. I finally had to block all email connections till I found how to limit connections to 1. My regulars customers were not happy.