Chapter Summary

Public folder replication provides fault tolerance and load balancing through redundancy, and it can be used to optimize communication over the messaging network. Instead of having all users access a single instance somewhere, you can provide a public folder replica locally for faster and more reliable client access. Public folder replication works within an organization. Between organizations, replication is supported by means of the InterOrg Replication utility. Exchange 2000 Server allows you to create or eliminate public folder replicas at any time.

The public folder replication process follows the multimaster model, which means that you can work with the public folder contents from any location. Public folder replication based on e-mail messages guarantees that changes made on one instance are propagated to all other instances to ensure the uniformity of data. The multimaster model allows you to distribute the workload of public folder servers.

Public folder replication is a very complex process that fills new public folders, keeps all replicas up to date, and detects removed public folder instances. In addition, lost replication messages and outdated servers that have been restored from an old backup must be detected, as well as possible replication conflicts. New public folder replicas and outdated servers are synchronized via backfill. Replicas are kept synchronized through replication messages, which contain updated items and their state information. By checking the state information, the most recent items can be detected. Replication conflicts must be resolved manually. The PFRA will send public folder conflict messages, including the conflicting items as attachments, to the users who created the conflict and the public folder owners. Conflict messages are also posted into the public folder and replicated to all other instances.