Neohapsis is currently accepting applications for employment. For more information, please visit our website www.neohapsis.com or email email@example.com
From: Gary Smith (gary.smithholdstead.com)
Date: Mon Apr 26 2010 - 17:45:54 CDT
I'm working on load balancing some sqlgrey servers using ipvsadm (non of the other bells and whistles, just the director itself). Anyway, at first glimps things look like they are running well until I find that I have a lot of connections in ESTABLISHED mode running on the sqlgrey real servers. Looking at the director there are corresponding active connections, and finally, looking at postfix, there are only a few active connections. I have worked with the ipvsadm group to ensure arp routing and other items are taken care of as per their recommendations.
What I am seeing is that postfix seems to be sending the close request down the pipe to the load balancer and the director isn't responding (properly?), postfix is then marking the connection as FIN_WAIT, and finally, the connection is being dropped by the postfix server. The problem appears to be that the director isn't either passing the request forward or isn't acknowledging it at all.
Now, when I swing the postfix directly to the IP of one of the real nodes, no problem. So, I was thinking maybe persistence. So I change director to be sticky for 15 minutes, but no go.
Has anyone seen this behavior before on a load balanced policy server?
Anyone have any ipvsadm scripts for a policy server they would like to share? I'm using wlc nat'ed connections currently.