A key part of virtually any web farm is keeping the various nodes of the web farm in sync. This applies to each of the three types of web farm configurations described above.
In addition to the web content, there are various components that make up a web farm's website. They include, but aren't limited to, the IIS configuration, SSL certificates, content, session state, database, components in the Global Assembly Cache (GAC), and COM+ components. Often it is necessary to automatically keep this content in sync between the server nodes.
Various tools and programs exist to support this. Microsoft provides a few options, and there are many third-party vendors that have created extensive applications to take care of content replication. This section covers some of Microsoft's solutions and briefly discusses additional tools.
The two most obvious aspects of a web farm that would use replication are website content and IIS Shared Configuration files. Both are stored at the disk level, so a disk replication tool is necessary to keep them in sync.
You might be asking why replication is necessary when the IIS configuration can point to a UNC share. Without ...