Closing traffic gracefully

close site to new traffic but let current finsh up

[paulsebring]

Let's say that I have an Apache webserver, and I have 100 concurrent users right this very second; 50 on one server and 50 on another (let's say I'm load balanced).
By what method could I prevent new traffic going to one particular server so that I could eventually take the server offline for whatever reason.
The caveat is, I'd like to allow the current active sessions on that particular server to terminate gracefully - allowing those users to finish buying or whatever they're doing.
Does someone have an example of a product or OpenSource app that will allow me to integrate this functionality?
Any input on this would be most appreciated!

[proper_bo]

What are you using to load balance at present?
By that I mean how do you currently split users between the two servers?

[sja65]

Depends on your load balancer. If you use IPVS, it is done by setting the weight of a machine to 0. It will then get no new connections, but continue serving existing connections. You can also set timeouts so that existing ip addresses or blocks will continue to go to the same server for a period of time.

This is the only load balancer I am familiar with, so I don't know what else is available.

[paulsebring]

Ah, thanks guys, this is very helpful!
I don't have a load balanced solution at present. But now I know that the solution to the issue lies within the HW load balancer itself.
Thanks for this.
I'll look into IPVS too!

Cheers