ParameterDescription

Default Value

SyntaxInteger

ExamplensDS5ReplicaPort:389

2.3.8.16 nsDS5ReplicaPriority

This attribute assigns a priority to replication agreements, controlling their rate of updates relative to peer agreements.

Prioritizing agreements is useful for a set of replicas that need to be updated in a particular order. For example, a replication topology might include a primary master replica with replication agreements configured for two replicas:

A geographically distant backup master replica connected by WAN, intended for disaster recovery

A local consumer replica that is accessed by client applications.

By default, or if equal priorities are assigned to the two replication agreements, the backup master replica and the consumer replica receive updates from the primary master concurrently. The relatively slower WAN connection to the backup master replica may eventually cause its update to fall behind relative to the consumer replica's update. If the primary master replica fails while the backup master update is behind, then some downtime for reinitialization would be required before the backup master replica could take over the role of the primary master replica.

To avoid this undesirable situation, you can use the replication agreement attribute nsds5ReplicaPriority to control the flow of updates so that the backup master replica is always equally or more updated than the consumer replica. Assigning a higher priority to the backup master relative to the consumer replica causes the agreement to the consumer to pause before sending any update that has not yet been sent to the backup master replica. When the pending updates are successfully sent to the backup master, the agreement to the consumer continues where it left off.

You can configure replication agreements in a priority hierarchy. An agreement with priority 0 transmits updates at an unlimited rate. An agreement with priority 1 depends on the progress of any agreement with priority 0; the priority 1 agreement pauses transmission whenever a priority 0 agreement update falls behind. Likewise, an agreement with priority 2 depends on the progress of all agreements with priority 0 and 1.

NOTE:

When assigning priority values, remember that the highest priority is 0, while lower priority values are any integers greater than 0 and up to 2147483647.

Parameter

Description

Entry DN

cn=ReplicationAgreementName, cn=replica, cn=suffixDN, cn=mapping tree, cn=config

 

 

Valid Range

0 to maximum 32-bit integer (2147483647)

 

 

Default Value

0, which means the agreement does not pause to wait for other agreements

 

 

Syntax

Integer

 

 

Example

nsDS5ReplicaPriority: 1

 

 

2.3.8.17 nsDS5ReplicaReapActive

This read-only attribute specifies whether the background task that removes old tombstones (deleted entries) from the database is active. See “nsDS5ReplicaTombstonePurgeInterval” for

86 Core server configuration reference