Designing a Highly Available Deployment

High availability implies an agreed minimum “up time” and level of performance for your directory service. Agreed service levels vary from organization to organization. Service levels might depend on factors such as the time of day systems are accessed, whether or not systems can be brought down for maintenance, and the cost of downtime to the organization. Failure, in this context, is defined as anything that prevents the directory service from providing this minimum level of service.

This chapter covers the following topics:

• Availability and Single Points of Failure

• Using Replication and Redundancy for High Availability