HP UX Red Hat Direry Server Software manual Configuring Cascading Replication, 298

Chapter 8. Managing Replication

These two attributes may be present in the nsds5ReplicationAgreement object class, which is used to describe replication agreements. Set the attributes at any time by using changetype:modify with the replace operation. The change takes effect for the next update session if one is already in progress.

NOTE

If either attribute is set to a negative value, Directory Server sends the client a message and an LDAP_UNWILLING_TO_PERFORM error code.

The two attributes are designed so that the nsds5ReplicaSessionPauseTime interval will always be at least one second longer than the interval specified for nsds5ReplicaBusyWaitTime. The longer interval gives waiting suppliers a better chance to gain consumer access before the previous supplier can re-access the consumer.

•If either attribute is specified but not both, nsds5ReplicaSessionPauseTime is set automatically to 1 second more than nsds5ReplicaBusyWaitTime.

•If both attributes are specified, but nsds5ReplicaSessionPauseTime is less than or equal to nsds5ReplicaBusyWaitTime, nsds5ReplicaSessionPauseTime is set automatically to 1 second more than nsds5ReplicaBusyWaitTime.

If Directory Server has to automatically reset the value of nsds5ReplicaSessionPauseTime, the value is changed internally only. The change is not visible to clients, and it not saved to the configuration file. From an external viewpoint, the attribute value appears as originally set.

Replica busy errors are not logged by default because they are usually benign. To see the errors, turn on the replication error logging, log level 8192. The log levels are described in more detail in the Directory Server Configuration, Command, and File Reference.

6. Configuring Cascading Replication

This section provides information on setting up cascading replication. The steps described in this section provide a high-level overview of the procedure, and cross-references to the detailed task descriptions are provided at each step.

Setting up cascading replication, as shown in Figure 8.4, “Cascading Replication”, has three major steps, for each server in the scenario, the supplier on server A, which holds a read-write replica; the consumer/supplier on hub server B, which holds a read-only replica; and the consumer on server C, which holds a read-only replica:

•Section 6.1, “Configuring the Read-Write Replica on the Supplier Server”

•Section 6.2, “Configuring the Read-Only Replica on the Consumer Server”

298