DOCUMENT:Q241186 11-NOV-2000 [exchange] TITLE :XADM: DirRep Bridgeheads Generate Unnecessary Notifications PRODUCT :Microsoft Exchange PROD/VER:winnt:5.5 OPER/SYS: KEYWORDS:exc55 kbExchange550preSP4fix kbExchange550sp4Fix ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Exchange Server, version 5.5 ------------------------------------------------------------------------------- SYMPTOMS ======== Directory replication may take several hours on a large Exchange Server site that has many servers if this site also has a directory bridgehead server with many downstream sites attached to it. At each replication interval, the bridgehead server can receive updates to (2 X number of sites) directory contexts, which it has to pass on to the other servers within its own site. These intrasite remote procedure call (RPC) updates are serialized and queued. If there are n downstream sites and the bridgehead has y servers in its own site, the bridgehead has up to (n X y X 2) directory replication updates to send to its local site. The issue is that the bridgehead always sends a change notification for all contexts to all servers in its site even if there have been no directory changes in the remote sites. When you multiply the number of updates by the replication pause interval between each update, the whole process can take some time (several hours in extreme cases). CAUSE ===== The speed of directory replication can be affected by many factors; however, in this particular case, the issue is caused by the fact that the notification mechanism on the directory replication bridgehead servers generates notifications for downstream naming contexts regardless of whether there are changes or not. On large Exchange Server systems, this behavior can cause valid directory changes to be queued behind a large number of notifications containing no real information. RESOLUTION ========== To resolve this problem, obtain the latest service pack for Exchange Server 5.5. For additional information, please see the following article in the Microsoft Knowledge Base: Q191014 XGEN: How to Obtain the latest Exchange Server 5.5 Service Pack STATUS ====== Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 5.5 . This problem was first corrected in Exchange Server 5.5 Service Pack 4. Additional query words: ====================================================================== Keywords : exc55 kbExchange550preSP4fix kbExchange550sp4Fix Technology : kbExchangeSearch kbExchange550 kbZNotKeyword2 Version : winnt:5.5 Issue type : kbbug Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2000.