XADM: Downloading an NNTP Message with a Large Header May Cause the Information Store to Consume 100% of CPU Time

ID: Q197491

The information in this article applies to:

SYMPTOMS

The Microsoft Exchange information store process (Store.exe) may consume 100 percent of the server's processor time. This is viewed by using the Windows NT Performance Monitor utility, clicking the Object:Process and the Counter:% CPU Utilization. Also, viewing the "% CPU Utilization" of all of the threads being used by the store process (in Performance Monitor, click Object:Thread and Instance:STORE; add all of the instance STORE to the chart) one thread will appear to be consuming 100 percent of the CPU time.


CAUSE

An NNTP client was downloading a NNTP message from a folder in the Public Store, this message had a subject line greater than 20 KB. The buffer being used to hold the subject line was hardcoded at 20 KB. Therefore the code was continually looping trying to read in the contents of the subject line that were past this 20 KB limit. This process resulted in high CPU usage by the information store process.


RESOLUTION

A supported fix that corrects this problem is now available from Microsoft, but has not been fully regression tested and should be applied only to systems experiencing this specific problem. If you are not severely affected by this specific problem, Microsoft recommends that you wait for the next Microsoft Exchange Server version 5.5 service pack that contains this fix.

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 on support costs, please go to the following address on the World Wide Web:

http://support.microsoft.com/support/supportnet/default.asp
The English version of this fix should have the following file attributes or later:
Component: Information Store 

   File Name    Version
   ---------------------
   Gapi32.dll   5.5.2502
   Mdbmsg.dll   5.5.2502
   Store.exe    5.5.2502

NOTE: If you contact Microsoft to obtain this fix, a fee may be charged. This fee is refundable if it is determined that you only require the fix you requested. However, this fee is non-refundable if you request additional technical support, if your no-charge technical support period has expired, or if you are not eligible for standard no-charge technical support.

For more information about eligibility for no-charge technical support, see the following article in the Microsoft Knowledge Base:
Q154871 Determining If Your Product Is Eligible for No-Charge Technical Support


STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 5.5.

Additional query words: crash hang 


Keywords          : 
Version           : WinNT:5.5
Platform          : winnt 
Issue type        : kbbug

Last Reviewed: August 3, 1999