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Oracle Directory Server Enterprise Edition Administration Guide 11g Release 1 (11.1.1.5.0) |
Part I Directory Server Administration
2. Directory Server Instances and Suffixes
3. Directory Server Configuration
6. Directory Server Access Control
7. Directory Server Password Policy
8. Directory Server Backup and Restore
9. Directory Server Groups, Roles, and CoS
10. Directory Server Replication
Planning Your Replication Deployment
Recommended Interface for Configuring and Managing Replication
Summary of Steps for Configuring Replication
Summary of Steps for Configuring Replication
Enabling Replication on a Dedicated Consumer
To Create a Suffix for a Consumer Replica
To Perform Advanced Consumer Configuration
To Create a Suffix for a Hub Replica
To Modify Change Log Settings on a Hub Replica
Enabling Replication on a Master Replica
To Create a Suffix for a Master Replica
To Modify Change Log Settings on a Master Replica
Configuring the Replication Manager
Using a Non-Default Replication Manager
To Set A Non-Default Replication Manager
To Change the Default Replication Manager Password
Creating and Changing Replication Agreements
To Create a Replication Agreement
To Change the Destination of a Replication Agreement
Considerations for Fractional Replication
To Configure Fractional Replication
To Configure Replication Priority
To Initialize a Replicated Suffix from a Remote (Supplier) Server
Replica Initialization From LDIF
To Initialize a Replicated Suffix From LDIF
To Export a Replicated Suffix to LDIF
Filtering an LDIF File for Fractional Replication
Initializing a Replicated Suffix by Using Binary Copy
Restrictions for Using Binary Copy With Replication
Making a Binary Copy for Initializing a Server
Initializing Replicas in Cascading Replication
To Initialize Replicas in Cascading Replication
Incrementally Adding Many Entries to Large Replicated Suffixes
To Add Many Entries to Large Replicated Suffixes
Replication and Referential Integrity
To Configure Replication Operations for SSL
To Configure Client Authentication Based Replication for SSL
Configuring Network Parameters
Scheduling Replication Activity
To Schedule Replication Activity
Modifying the Replication Topology
Changing the Replication Manager
Managing Replication Agreements
Disabling a Replication Agreement
Enabling a Replication Agreement
Deleting a Replication Agreement
Promoting or Demoting Replicas
To Promote or Demote a Replica
To Disable a Replicated Suffix
Keeping Replicated Suffixes Synchronized
Moving a Master Replica to a New Machine
To Remove a Master From an Existing Replication Topology
To Add a Master to an Existing Replication Topology
Replication With Releases Prior to Directory Server 11g Release 1 (11.1.1.5.0)
Replicating Between Directory Server 11g Release 1 (11.1.1.5.0) and Directory Server 6 or 5.2
To Enable the Retro Change Log
To Configure the Retro Change Log to Record Updates for Specified Suffixes
To Configure the Retro Change Log to Record Attributes of a Deleted Entry
Access Control and the Retro Change Log
Getting Replication Status in DSCC
Getting Replication Status by Using the Command Line
Solving Common Replication Conflicts
Solving Replication Conflicts by Using DSCC
Solving Replication Conflicts by Using the Command Line
To Rename a Conflicting Entry That has a Multivalued Naming Attribute
To Rename a Conflicting Entry With a Single-Valued Naming Attribute
Solving Orphan Entry Conflicts
Solving Potential Interoperability Problems
13. Directory Server Attribute Value Uniqueness
15. Directory Server Monitoring
Part II Directory Proxy Server Administration
16. Directory Proxy Server Tools
17. Directory Proxy Server Instances
19. Directory Proxy Server Certificates
20. Directory Proxy Server Load Balancing and Client Affinity
21. Directory Proxy Server Distribution
22. Directory Proxy Server Virtualization
23. Virtual Data Transformations
24. Connections Between Directory Proxy Server and Back-End LDAP Servers
25. Connections Between Clients and Directory Proxy Server
26. Directory Proxy Server Client Authentication
27. Directory Proxy Server Logging
28. Directory Proxy Server Monitoring and Alerts
Part III Directory Service Control Center Administration
Directory Server enables you to perform all forms of replication including multimaster replication between machines connected through a wide area network (WAN). This replication allows supplier servers to initialize and update consumers by making optimal use of the bandwidth over networks with higher latency and lower bandwidth.
Note - When deploying or troubleshooting a replication topology that replicates over a WAN, you must check network speed, latency, and packet loss. Network problems in any of these areas might cause replication delay.
In addition, replication data transfer rates will always be less than what the available physical medium allows in terms of bandwidth. If the update volume between replicas cannot physically be made to fit into the available bandwidth, tuning will not prevent your replicas from diverging under heavy update load. Replication delay and update performance are dependent on many factors, including but not limited to: modification rate, entry size, server hardware, error rates, average latency, and average bandwidth.
If you have questions about replication in your environment, contact your Sun Service Provider.
Internal parameters of the replication mechanism are optimized by default for WANs. However, if you experience slow replication due to the factors mentioned previously, you might want to empirically adjust the window size and group size parameters. You might also be able to schedule your replication to avoid peak network times, thus improving your overall network usage. Finally, Directory Server supports the compression of replication data to optimize bandwidth usage.
The window and group network parameters determine how the replication mechanism groups entries to send them more efficiently over the network. These parameters affect how suppliers and consumers exchange replication update messages and acknowledgments. The parameters are configurable in every replication agreement, which allows you to tailor the replication performance according to the specific network conditions of each consumer.
Monitor the effects of any modifications that you make and adjust the parameters accordingly. Refer to Getting Replication Status for instructions. You do not need to interrupt replication to modify the window size and group size parameters.
The window size (default value 10) represents the maximum number of update messages that can be sent without immediate acknowledgment from the consumer.
It is more efficient to send many messages in quick succession instead of waiting for an acknowledgment after each message. Using the appropriate window size, you can eliminate the time replicas spend waiting for replication updates or acknowledgments to arrive.
If your consumer replica is lagging behind the supplier, increase the window size to a higher value than the default, such as 100, and check replication performance again before making further adjustments. When the replication update rate is high and the time between updates is therefore small, even replicas connected by a local area network (LAN) can benefit from a higher window size.
You can use DSCC to perform this task. For information, see Directory Service Control Center Interface and the DSCC online help.
$ dsconf set-repl-agmt-prop -h host -p port suffix-DN consumer-host:consumer-port\ transport-window-size:value
For example:
$ dsconf set-repl-agmt-prop -h host2 -p 1389 dc=example,dc=com host1:1389 \ transport-window-size:20
The group size (default value 1) represents the maximum number of data modifications that can be bundled into a single update message. If the network connection appears to be impeding replication, increase the group size to a higher value than the default, such as 10, and recheck replication performance.
When increasing the group size, make sure that the following are true:
The window size is set significantly higher than the group size.
The window size divided by the group size is much greater than the value for nsslapd-maxThreadsPerConn under cn=config on the consumer (typically twice as large).
When the group size is set higher than 1, the supplier does not wait to fill a group before sending updates to the consumer.
You can use DSCC to perform this task. For information, see Directory Service Control Center Interface and the DSCC online help.
$ dsconf set-repl-agmt-prop -h host -p port suffix-DN \ consumer-host:consumer-port transport-group-size:value
For example:
$ dsconf set-repl-agmt-prop -h host2 -p 1389 dc=example,dc=com host1:1389 \ transport-group-size:10
If immediate synchronization between your replicas is not critical, you can schedule replication during periods of low network usage. Replication of data should complete significantly faster when the network is more available.
You can schedule replication to start and end at a certain time of day, on a daily or weekly basis. You can do this independently for every consumer through its replication agreement. The new schedule will take effect immediately, causing the next replication of data for the corresponding consumer to be delayed until first allowed by the schedule.
You can use DSCC to perform this task. For information, see Directory Service Control Center Interface and the DSCC online help.
$ dsconf set-repl-agmt-prop -h host -p port suffix-DN \ host:port repl-schedule:value
For example, if you want to set replication to occur between 2:00 and 4:00 every night, type:
$ dsconf set-repl-agmt-prop -h host2 -p 1389 dc=example,dc=com host1:1389 \ repl-schedule:"0200-0400 0123456"
where 0123456 indicate the days of the week, with 0 representing Sunday, 1 representing Monday, and so on.
To reduce the bandwidth used by replication, you may configure replication to compress the data that is sent when updating consumers. The replication mechanism uses the Zlib compression library. Both supplier and consumer must be running on a Solaris or Linux platform to enable compression.
You should empirically test and select the compression level that gives you best results for your expected replication usage in your WAN environment. Do not set this parameter in a LAN where there is wide network bandwidth because the compression and decompression computations will slow down replication.
You cannot use DSCC to perform this task. Use the command line, as described in this procedure.
$ dsconf set-repl-agmt-prop -h host -p port suffix-DN \ consumer-host:consumer-port transport-compression:level
where level can be high, medium, low, or none.
For example, to use the fastest compression when sending replication updates to the consumer on host1:1389, type:
$ dsconf set-repl-agmt-prop -h host2 -p 1389 dc=example,dc=com host1:1389 \ transport-compression:high
For more information about setting the compression level, see Oracle Directory Server Enterprise Edition Reference.