I’ll be honest , I’m not 100% sure what this thing is. It appears to be some more intelligent software based application load balancer and workload router for IIS 7 based web servers.
“Microsoft Application Request Routing for IIS7 is a proxy based routing module that forwards HTTP requests to content servers based on HTTP headers and server variables, and load balance algorithms.
Application Request Routing can be used to:
- Increase application availability and scalability.
- Better utilize content server resources.
- Facilitate application deployment including pilot management and A/B testing.
- Lower management costs and create opportunities for shared hosters”
You can learn more here where there are links to documentation. There are x86 and x64 versions that you can download and install. It looks pretty powerful and I’m going to have to find 120 minutes somewhere to read a bit more about it. On the face of it, it looks like a cheaper alternative to pricey hardware based load balancers like the F5 Big-IP or rely on the basic functionality of Windows load balancing (which does work!).