Replication Concepts - Netscape DIRECTORY SERVER 6.2 - DEPLOYMENT Deployment Manual

Introduction to Replication
Replication enables you to provide a highly available directory service, and to
geographically distribute your data. In practical terms, replication brings the
following benefits:
• Fault tolerance/Failover—By replicating directory trees to multiple servers,
you can ensure your directory is available even if some hardware, software, or
network problem prevents your directory client applications from accessing
a particular Directory Server. Your clients are referred to another Directory
Server for read and write operations. Note that to support write failover
you must have a multi-master replication environment.
• Load balancing—By replicating your directory tree across servers, you can
reduce the access load on any given machine, thereby improving server
response time.
• Higher performance and reduced response times—By replicating directory
entries to a location close to your users, you can vastly improve directory
response times.
• Local data management—Replication allows you to own and manage data
locally while sharing it with other Directory Servers across your enterprise.
Before defining a replication strategy for your directory information, you should
understand how replication works. This section describes:
•

Replication Concepts

• Data Consistency
Replication Concepts
When you consider replication, you always start by making the following
fundamental decisions:
• What information you want to replicate.
• Which server (or servers) hold the master copy, or read-write replica, of that
information.
• Which server or servers hold the read-only copy, or read-only replica, of the
information.
• What should happen when a read-only replica receives an update request, that
is, which server should it refer the request to.
108 Netscape Directory Server Deployment Guide • December 2003