Building resilient IT systems – IIS
Another main component of windows systems is the Internet Information Services aka IIS. This is what runs the web applications which we are so familiar with today.
Previously with IIS 6 and below, there is no easy way to synchronize the IIS metabase between 2 or more servers. The only way to do that is to install the IIS metabase editor and do a copy and paste between the source and destination servers.
With the introduction of IIS 7 and shared configuration, it is now possible to share the configuration between web servers so that the IIS running in all the servers are in sync and have the exact IIS configuration (assuming that the folder structure and user permissions are the same in all the web servers)
You can use the file share method to point the other web servers to the primary web server, however this may mean that in the event that the primary server is down, the other web servers IIS configuration may not reflect correctly as well. One quick way to work around this is to use DFSR to replicate the IIS configuration folder across the servers and have IIS point to a local path instead.
How to build a resilient IIS (7.0 and above)
In order to set up shared configuration, you can refer to this article or this video guide. In fact there are a whole lot of guide which can easily be found, but in general setting up shared configuration is extremely simple.
An alternative to using DFSR can be found here, where they use offline files to ensure the files are always available. Do note that in the comments, there are mentions that using DFSR might be a better option rather than offline files.
Once you have shared configuration up and running, you will have multiple servers hosting the same IIS content. However this is purely hosting, you still need a load balancing appliance/application to perform the load balancing.
To solve this, you can either use Windows network load balancing or a hardware load balancer box such as the likes from F5, NetApp, Radware (in no particular order).
This link explains how to use Microsoft Application Request Routing and in addition, the article provides 2 links somewhere at the end which teaches you how to integrate IIS with a hardware or software load balancer.
The benefits of a load balancer appliance is that generally they offer something known as global load balancing, where you have your servers all over the world and the load balancer has the capability to load balance your requests across these servers