Clustering and failover

The key to any production environment is the enablement of redundancy to account for planned or unplanned outages.

When creating a redundant environment, it's important to understand the terminology and options. Clustering, as enabled by IBM® Domino®, is the ability to replicate IBM® Domino® databases across multiple servers. This is typically utilized with the IBM® Domino® mail databases. IBM Traveler servers can take advantage of mail database clustering. However, IBM Traveler itself cannot take advantage of IBM® Domino® database clustering due to the fact that much of the IBM Traveler server data is not stored in a IBM® Domino® Database.

High Availability (HA) is a general term that implies a high percentage of system availability ensured by a redundant infrastructure. IBM® Domino® Clustering is how IBM® Domino® can provide high availability of mail access. It is now possible to set up multiple IBM Traveler servers using a shared enterprise database. If a server in the pool goes offline, devices can connect to other servers in the pool without loss of data. This pool of IBM Traveler servers in conjunction with mail clustering provides highly available mobile mail access. Although clustering and high availability can be considered synonymous, the term High Availability is used with IBM Traveler to avoid confusing the implementation with that of Domino® clustering. Disaster recovery (DR) typically refers to enabling a backup environment that will only be utilized in the event of a failure of the primary service. A disaster recovery environment may or may not require manual intervention. IBM Traveler, even as a stand alone server, can be setup for disaster recovery.

Which degree of redundancy is implemented will depend on both your availability requirements as well as the infrastructure investment desired.