XCLN: Factors affecting Directory Replication speed

• Microsoft Exchange Server, versions 4.0, 5.0, 5.5

SUMMARY

This article describes some of the reasons why Microsoft Exchange Server Directory Replication can take longer than expected.

MORE INFORMATION

The following are factors that could affect the speed of Directory Replication within Microsoft Exchange Sites as well between Sites.

1. Check the Microsoft Exchange Server Message Transfer Agent(MTA) queues to make sure that messages are flowing out of the queues at a reasonable rate. Directory Replication between Sites is message based and if messages are not flowing, Directory Replication will not take place. If the MTA is bogged down with messages, this maybe be due to excessive processor load, insufficient hardware, or insufficient memory, among other reasons.



2. Check the load on the sending and receiving Microsoft Exchange Servers. This can be done using the Windows NT Performance Monitor and looking at the %Processor Time counter of the Processor Object. If the %Processor Time is consistently high (above 80%) determine which process is useing most of the CPU cycles.
   
   If possible, stop the CPU intensive processes until the Directory Replication is complete. Make sure that you are not running CPU intensive programs, like an OpenGL screen saver (like Pipes), that may unnecessarily take up CPU cycles.
   
   It is beneficial to run Performance Monitor from a computer other than the one you are monitoring. This will allow you to catch screen saver processes running on the Microsoft Exchange Server computer.



3. If the number of addresses being replicated is very large, do not repeatedly manually request an update of all entries in the Global Address List.



4. Check the replication schedule. For the purpose of getting the replication done as soon as possible, it may be advisable to set the replication schedule to Always.



5. Check the topology of your Microsoft Exchange Organization. It may be possible that changes made to the Directory take a while to propagate to all parts of the Organization, if the number of intermediate hops is large.
   
   For more information on this issue, please refer to the following Microsoft Knowledge Base article:

   Q148381 XADM: Directory Replication Takes Too Long

Additional query words:

Keywords : XADM exc4 exc5 exc55
Version : winnt:4.0,5.0,5.5
Platform : winnt
Issue type :