Data Replication Architecture

I'm currently working on an infrastructure challenge on data replication and thought of updating my learning in my blog:

There are several things to consider while working on server farms, where servers are located in multiple sites across the globe.

Peer to peer replication and Transaction Replications are few options that are available and are commonly used. This require not only configuration changes on the server but also require development consideration.

Peer to peer replication are available only in SQL server 2008

The servers on the farm should have identical O/S version, SQL server version, including the patches that are applied.

Database Schema should be identical

Identity column do not work in replication (atleast from SQL 2005)

Primary key with alpha-numeric or composite key will help resolve idenity column