Topologies for Web Synchronization
You can choose from a variety of Microsoft SQL Server Web synchronization replication topologies. Common ways to configure Web synchronization include:
Multiple Microsoft Internet Information Services (IIS) systems and SQL Server republishing
For information about configuring Web synchronization, see Configuring Web Synchronization.
In the simplest topology, IIS, the SQL Server Publisher, and the SQL Server Distributor all reside on a single server. Subscribers synchronize by connecting to IIS on the Publisher. The Publisher can be located behind a firewall.
This configuration is recommended only for intranet scenarios. For other scenarios, it is recommended that the IIS server and SQL Server Publisher/Distributor be on separate computers.
If you need to support very large numbers of Subscribers that synchronize at the same time, you can partition the work across multiple computers running IIS.
If further load balancing is required on the computer running SQL Server, you can create a republishing hierarchy on multiple computers. The top-level Publisher publishes data to Subscribers, which in turn republish the data, load balancing requests from the Subscribers.
Subscribers can only synchronize with a specific Publisher. For example, a Subscriber to republisher A cannot synchronize with republisher B when A is not available.