I have an NLB configured for two web servers. The NLB is a software NLB configured on Windows Server 2008 R2. The web servers are IIS servers. For a request of 5000 users, all my requests are going to one web server. So when does NLB send requests to other server. Also how do I configure NLB for sticky sessions ?
NLB configuration
nlb
Best Answer
NLB will distribute the load according to the chosen filtering mode & affinity settings for your NLB cluster. If you've set "Single" filtering mode, all traffic will go to a single server. If you've selected "Multiple host", the affinity decides which host will receive the traffic of recurring users. If you've chosen Single/Class C affinity, all users from the same IP / IP class C range will hit the same server (beware proxies & internal network topologies in this case).
Furthermore, even in multiple host mode, you can choose a distribution factor under the port rules so one server may be at 100% while the other is at 0%.
I've got a short video on my blog on how to setup a simple NLB cluster that shows the filtering mode & affinity settings: http://improve.dk/blog/2008/03/08/using-network-load-balancing-for-availability-and-scalability