IIS network load balancing

Question

I have a clustered server with 4 nodes running Win server 2008 r2 with IIS 7. Fail over kicks in when one of nodes fails but is there a way to have it round robin distribute incoming calls to different server? This happens when incoming requests come from different client but our investigation shows that if there is one client that is making many requests, they all go to the same server. I would like to the server to round robin request so that node 1 receives first request, node 2 receives second request and so on. Each request could take a long time and having all requests go to the same node when I have 3 others idling is causing us perf issue. Thanks

Answer 1

Round Robin Load Balancing will not distribute traffic coming from one destination. You will need to configure your load balancer to 'Least Connections'

Basically the NLB passes a new connection to the pool member or node that has the least number of active connections.

Answer 2

NLB port rules have a couple of properties that control how requests are routed. The relevant properties seem to be:

• Filtering mode - specifies whether a single host or multiple hosts in the cluster handle traffic for the given port
• Affinity - controls how traffic is routed to hosts in the cluster

It is likely you need to set the Affinity value to none, which allows requests to be routed to multiple hosts within the cluster. The docs do not state whether round-robin or another algorithm is used for load balancing.

For more on Filtering Mode and Affinity: Network Load Balancing Manager Properties

How to: Edit a Network Load Balancing Port Rule