Microsoft KB Archive/813814

= Exchange networking performance is very slow =

Article ID: 813814

Article Last Modified on 2/21/2007

-

APPLIES TO


 * Microsoft Exchange 2000 Server Standard Edition

-





SYMPTOMS
The amount of mail that passes through your Exchange server may substantially decrease, and all network-related functions on your Exchange server may also slow down. Also, the network utilization percentage in Task Manager may be as high as 99 percent.



CAUSE
This problem may occur in Exchange environments that include a large number of Active Directory directory service domains in a single Exchange 2000 Server organization. Additionally, this problem may occur in a highly distributed environment that has a large number of administrative groups.

Note A &quot;large&quot; number of domains or administrative groups is more than 100 domains or administrative groups.

For each domain that participates in an Exchange organization, the Exchange Recipient Update Service (RUS) must add Access Control Entries (ACEs) to the Access Control Lists (ACLs) of several Active Directory objects. As the number of ACEs increases, the size of the ACL for an object grows. If the total size of an Active Directory object's attributes including the ACL exceeds 32,768 bytes, the Exchange DsAccess component cannot cache that attribute.

Note DsAccess provides a shared memory caching warehouse of directory information to be used by several Exchange components. This reduces the number of queries that go directly to the Windows 2000 Active Directory, and reduces the cost overhead that is associated with direct access to the Active Directory.

If the DsAccess component cannot cache the object's attributes, the Exchange server must now contact a domain controller or a global catalog server to retrieve the attributes. This causes a great deal of network utilization that can be further increased when the data is requested frequently, as is the case with public folder data or when routing e-mail.



Cumulative Rollup Information
To resolve this problem, obtain the September 2003 Exchange 2000 Server Post-Service Pack 3 (SP3) Rollup. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

824282 September 2003 Exchange 2000 Server Post-Service Pack 3 Rollup

Hotfix Information
A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next Microsoft Exchange 2000 Server service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question. Component:

The English version of this fix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

  Date         Time   Version           Size     File name ---  05-Feb-2003  18:49  6.0.6413.0        577,536  Dsaccess.dll 05-Feb-2003 17:58  6.0.6413.0        184,320  Dscmsg.dll 01-Aug-2002 06:37  6.0.6300.1         84,480  Spuninst.exe After you install this hotfix, the following event is logged in the Event Viewer Application log if this issue exists on your server: Event ID:2112

Event Type: Warning

Event Source: MSExchangeDSAccess

Description: An attribute on  is too large to be cached. Requested size was, maximum cacheable is. Performance may be degraded. For more information, click http://search.support.microsoft.com/search/?adv=1.

This event is only logged if DsAccess logging has been configured to maximum. To configure DsAccess logging:
 * 1) Click Start, point to Programs, point to Microsoft Exchange, and then click System Manager.
 * 2) Expand your organization name, expand Administrative Groups, expand your administrative group, and then expand Servers.
 * 3) Right-click your Exchange 2000 Server computer, and then click Properties.
 * 4) Click Diagnostics Logging.
 * 5) In the left pane, click MSExchangeDSAccess Service, and then click Cache in the right pane.
 * 6) Under Logging Level, click Maximum, and then click OK.

STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.



MORE INFORMATION
When this issue occurs, Exchange servers may start losing connectivity to domain controllers. And, the Exchange servers may receive incorrect topology information from DSAccess. The following events may be logged in the event log: Event Type: Information

Event Source: MSExchangeDSAccess

Event Category: Topology

Event ID : 2080

Computer: SERVERNAME

Description: Process EMSMTA.EXE (PID=4232). DSAccess has discovered the following servers with the following characteristics: (Server name | Roles | Reachability | Synchronized | GC capable | PDC | SACL right | Critical Data | Netlogon | OS Version) In-site: DC-Server003. .COM CDG 7 7 1 0 1 1 7 1 DC-Server002. .COM --G 1 7 1 0 1 1 7 1 DC-Server001. .COM --- 0 0 0 0 0 0 0 0 DC-Server001. .COM --- 0 0 0 0 0 0 0 0 DC-Server003. .COM --G 1 7 1 0 1 1 7 1 DC-Server004. .COM --G 1 7 1 0 1 1 7 1 DC-Server006. .COM --G 1 7 1 0 1 1 7 1 DC-Server007. .COM --G 1 7 1 0 1 1 7 1 DC-Server004. .COM --G 1 7 1 0 1 1 7 1 DC-Server008. .COM --G 1 7 1 0 1 1 7 1

Out-of-site:

Child-DC-Server002.child. .COM --- 0 0 0 0 0 0 0 0 Child-DC-Server001.child. .COM --G 1 7 1 0 1 1 7 1 Child-DC-Server005.child. .COM --G 1 7 1 0 1 1 7 1 Child-DC-Server003.child. .COM --G 1 7 1 0 1 1 7 1

Event ID: 2070

Category: Topology

Source: MSExchangeDSAccess

Type: Information

Machine: SERVERNAME

Message: Process EMSMTA.EXE (PID=3888). DSAccess lost contact with domain controller DCNAME.DOMAIN.COM. Error was 80040933 (000021A8: LdapErr: DSID-0C060529, comment: The server is sending data faster than the client has been receiving. Subsequent requests will fail until the client catches up, data 0, vece). DSAccess will attempt to reconnect with this domain controller when it is reachable.

These symptoms may appear to be network connectivity issues. However, these symptoms may occur if the ACL sizes exceed 32 KB. Sometimes, the domain controllers and the network may not appear to be overused.

To work around this issue, reduce the ACL sizes on the Exchange Configuration objects.

Additional query words: kbExchange2000preSP4septbarFix

Keywords: kbhotfixserver kbqfe kbenv kbqfe kbfix kbexchange2000presp4fix kbbug KB813814

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.