User manual REDHAT DIRECTORY SERVER 8.0 ADMINISTRATION

[. . . ] Directory Server 8. 0 Administration Guide A Guide for Using and Maintaining Red Hat Directory Server Publication date: January 15, 2008, updated on February 11, 2010 Ella Deon Lackey Administration Guide Directory Server 8. 0 Administration Guide A Guide for Using and Maintaining Red Hat Directory Server Edition 8. 0. 19 Author Ella Deon Lackey Copyright © 2008, 2009 Red Hat, Inc. The text of and illustrations in this document are licensed by Red Hat under a Creative Commons Attribution­Share Alike 3. 0 Unported license ("CC-BY-SA"). An explanation of CC-BY-SA is available at http://creativecommons. org/licenses/by-sa/3. 0/. In accordance with CC-BY-SA, if you distribute this document or an adaptation of it, you must provide the URL for the original version. [. . . ] Figure 8. 1, "Single-Master Replication" shows an example of single-master replication. 230 Multi-Master Replication Figure 8. 1. Single-Master Replication In this particular configuration, the ou=people, dc=example, dc=com suffix receives a large number of search requests. Therefore, to distribute the load, this tree, which is mastered on Server A, is replicated to two read-only replicas located on Server B and Server C. For information on setting up a single-master replication environment, see Section 8. 4, "Configuring Single-Master Replication". 8. 2. 2. Multi-Master Replication Directory Server also supports complex replication scenarios in which the same suffix (database) can be mastered on many servers. This suffix is held in a read-write replica on each server. This means that each server maintains a changelog for the read-write replica. This type of configuration can work with any number of consumer servers. Each consumer server holds a read-only replica. The consumers can receive updates from all the suppliers. The consumers also have referrals defined for all the suppliers to forward any update requests that the consumers receive. Such scenarios are called multi-master configurations. Figure 8. 2, "Multi-Master Replication (Two Masters)" shows an example of multi-master replication scenario with two supplier servers and two consumer servers. 231 Chapter 8. Multi-Master Replication (Two Masters) Figure 8. 3, "Multi-Master Replication (Four Masters)" shows a sample of multi-master replication scenario with four supplier servers and eight consumer servers. In this sample setup, each supplier server is configured with ten replication agreements to feed data to two other supplier servers and all eight consumer servers. 232 Cascading Replication Figure 8. 3. Multi-Master Replication (Four Masters) Multi-master configurations have the following advantages: · Automatic write failover when one supplier is inaccessible. · Updates are made on a local supplier in a geographically distributed environment. NOTE The speed that replication proceeds depends on the speed of the network. Plan changes and directory configuration accordingly, and realize that changes to one directory may not be quickly replicated to other directories over slow links, such as wide-area networks, in geographically-distributed environments. For the procedure to set up multi-master replication, see Section 8. 5, "Configuring Multi-Master Replication". 8. 2. 3. Cascading Replication In a cascading replication scenario, one server, a hub, acts both as a consumer and a supplier. It holds a read-only replica and maintains a changelog, so it receives updates from the supplier server that holds the master copy of the data and, in turn, supplies those updates to the consumer. Managing Replication replication is very useful for balancing heavy traffic loads or to keep master servers based locally in geographically-distributed environments. [. . . ] Encryption that uses the same key for both encrypting and decrypting. DES is an example of a symmetric encryption algorithm. Cannot be deleted or modified as it is essential to Directory Server operations. standard index sub suffix subagent substring index suffix superuser supplier supplier server supplier-initiated replication symmetric encryption system index T target target entry TCP/IP template entry time/date format TLS In the context of access control, the target identifies the directory information to which a particular ACI applies. Transmission Control Protocol/Internet Protocol. [. . . ]