I'm in the planning stages for a new 2013 farm and documenting out my topology etc...came to a question of Load Balancing and since this is the first farm I've built with the use of it I'm wondering if there is a need to set affinity balance on the WFE's in my 2013 farm. I plan to have two initially, the reason I ask is because in my review of the Web App Farm planning guide it mentioned the need for those to use affinity. I am planning to use a hardware balancer.
With SharePoint 2013 there is no need to configure sticky sessions (affinity) anymore, at least not for authentication. This is because login tokens are now cached in the new distributed cache service so every web server has them in memory:
However, it's probably not a bad idea to still use sticky sessions with SharePoint 2013 because of operational reasons like simpler logging and troubleshooting. A somewhat older but stil valid article on why to configure sticky sessions is this one: