Affinity or Sticky Sessions
July 24th, 2009
So what is Affinity? It is sticky sessions.. 
Then what is this “sticky session” thing you speak of?
Well when you connect to a website with NLB you are being passed from one server to the next depending on how many nodes or hosts you have. Every time you click a link it will essentially open a new connection which means if you were using Server1 and it is now server2’s turn to server a request then you will be moved to server2.
OK, so whats the big deal?
Well once it opens a new connection it will not save any info because it sees it as a new connection… This is a HUGE issue if you have to login to an app that is using NLB and you are sent to another server… you will have to re-login. So what sticky sessions does is allow you to use the same connection for all requests until you close the browser or leave the site.
Categories: NLB
[...] you will want to select “Multiple Hosts” and under “Affinity” select Single (This allows “sticky sessions”) Once you are finished here click “OK” and then “Next” on the “Port [...]