Article ID: 924047 - View products that this article applies to.
When you use a Microsoft Outlook client computer to connect to a front-end server that is running Microsoft Exchange Server 2003, you experience slow response times. Alternatively, you cannot connect to the Exchange 2003 server. These symptoms occur when you use one of the following protocols:
%SYSTEMROOT%\System32\LogFiles\HTTPERR\Log_Name.logNote For more information about how HTTP error log files are named, see the "More Information" section.
This problem occurs if the Microsoft Windows Server 2003-based computer that is running Exchange Server 2003 runs out of available nonpaged pool memory.
HTTP.sys is a kernel-mode driver that uses nonpaged pool memory for every RPC over HTTP connection. HTTP.sys stops accepting new connections when the available nonpaged pool memory drops under 20 megabytes (MB).
In 32-bit versions of Windows Server 2003, the size of the kernel nonpaged pool memory is fixed at 250 MB. Additionally, the maximum size of the kernel nonpaged pool memory is reduced to 128 MB when you use the /3GB switch in the Boot.ini file. Therefore, the nonpaged pool memory that is available to HTTP.sys is limited.
To support more RPC over HTTP connections, use one of the following methods:
For more information about RPC over HTTP, click the following link to view the document on the Microsoft MSDN Web site:
http://msdn.microsoft.com/en-us/library/aa378698.aspxFor more information about x64-based versions of Windows Server 2003, click the following link to view the document on the Microsoft Web site:
Microsoft has confirmed that this problem is caused by a limitation of 32-bit architecture. This problem affects the Microsoft products that are listed in the "Applies to" section.
Monitor nonpaged pool memoryYou can use the Memory Pool Monitor (Poolmon.exe) utility and the Gflags tool to monitor the usage of kernel nonpaged pool memory. Both these tools are available in the following folder of the Windows Server 2003 CD:
\Support\ToolsFor more information, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/177415/ )How to use Memory Pool Monitor (Poolmon.exe) to troubleshoot kernel mode memory leaks
HTTP error log file namesHTTP error log files are named according to whether the rollover is based on size, on date, or on time. The following table lists the naming conventions for the HTTP error log files:
For more information about HTTP error logging, click the following link to view the document on the Microsoft MSDN Web site:
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For more information about RPC over HTTP scalability, click the following link to view the document on the Microsoft Technet Web site: