----- Forwarded message from Stephen Satchell ----- > Marius Gologan: >> I'm running a stress test against Postfix, running smtp-source command with >> 1.000 parallel connections from one source IP. >> When postscreen is active, at about 400-460 connections I get "421 4.3.2 All >> server ports are busy". > > Please do not blame the messenger of the bad news. > > POSTSCREEN tries to hand off of connections to SMTPD. You are running > into the condition where all SMTPD ports are busy. > > No amount of POSTSCREEN tweaking will prevent that.
Also, the problem may not be in PostFix. You may need to tune your underlying host to handle high connection loads. If you look for how to tune a server to accept massive WWW loads, the same techniques can be used to increase the number of open sockets and ephemeral port numbers available. I won't repeat what dozens of HOWTO pages would tell you. ----- End of forwarded message from Stephen Satchell -----
