Microsoft Application Request Routing (ARR) for IIS 7.0 is a proxy-based routing module that forwards HTTP requests to application servers based on HTTP headers, server variables, and load balance algorithms.  

ARR Version 2 Beta 2 is an incremental release that includes all of the features from Version 1, and adds support for disk-based cache. More specifically, this feature allows IIS to compete as a cache proxy in a whole new market place:

Download ARRv2 beta 2 from:

· Microsoft Application Request Routing Version 2 for IIS7 Beta 2 (x86)

· Microsoft Application Request Routing Version 2 for IIS7 Beta 2 (x64)

What’s new in ARRv2 beta 2:

  • Disk-based caching (Improved in Beta 2)
    In addition to the kernel memory cache in ARR Version 1, Version 2 Beta 2 adds support for disk-based cache.  This feature is improved in Beta 2 with an introduction to secondary cache concept.
  • Cache hierarchy management
    Define and manage relationships between cache nodes, including support for the Cache Array Routing Protocol (CARP).  
  • Cache proxy node in CDN/ECN environment   (Improved in Beta 2)
    Because ARR is a proxy-based HTTP request routing module with support for disk cache and CARP, ARR can be used as a cache proxy in a CDN/ECN environment. This feature is improved in Beta 2 with support for more advanced routing rules, such as being able to set host headers to route requests accordingly.
  • Caching compressed objects
    Disk-based cache stores compressed objects so that the objects do not have to be compressed in real time for every request.  
  • Browse cached contents using IIS manager (New in Beta 2)
    Browse through cached contents across multiple drives in one consolidated graphical view in IIS manager.
  • Intelligent live request support (New in Beta 2)
    ARR is designed to work with Live Smooth Streaming to support live content requests without over-loading the live streaming server.
  • Caching while serving response
    Caching large content, such as a movie clip, may take some time. ARR Version 2 Beta 2 is capable of caching the content while serving the response immediately.


· Support for the beta release is available only on the forum.