[thelist] aol, session tracking, and load-balacing

Brian Cummiskey brian at hondaswap.com
Wed Jan 9 00:27:36 CST 2008

Jeff Wilhelm - TheList wrote:
> What type of load balancer is it? In our CoyotePoints we were able to get
> around this (I believe) by increasing the values of the client timeout and
> server timeout variables. 

I'm not sure what brand/make it is.  I can check with out infrastructure 
guys.   It is a hardware unit though.

Anthony Baratta wrote:
 > Are you 100% sure that the AOL clients are switching IPs during the 

I'm not exactly sure what is happening, but it seems to only be 
effecting AOL users.  No one else seems to be reporting problems.  All 
of the complaints that have come into customer service have been from 
@aol.com addresses.

 > What you are probably seeing is the load balancer switching web 
servers and the client is losing the session. Try setting the load 
balancer to "bind" the browser IP to a specific web server for a 
specific time. This way they always hit the same web server and the 
cookie / session info should not be lost.

Isn't this the inherit problem though?

David Dorward wrote:
 > AOL is known to use rotating proxy servers.

That's my understanding too.  AOL changes the IP of the client, thus the 
balancer doesn't have a current session for the new IP, and puts them 
randomly on one of 3 servers.

Anthony Baratta wrote:
 > The other way is to move to DB sessions, so you can hit either web 
server and get the proper session info from the Database.

I'm not sure we're ready to do that.  From a load perspective, that 
would add literally 5 million update/select queries a day.  We're 
running pretty hot as it is, and this spans multiple clients on multiple 
websites on multiple hardware in multiple datacenters.   It's really a 
last-resort effort that I really don't want to look at if there's a 
better way.

If I had it my way, I'd just put a "you use aol, get off the internet" 
banner on the top of the site and call it a day.  Unfortunately, I don't 
work for burger king.  lol

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