XADM: High CPU Utilization in STORE Process Due to Categorized Views

The Microsoft Exchange Server information store (Store.exe) process may appear to hang and/or consume a high percentage of the systems processor utilization. Using Windows NT performance monitor to view the "% Processor Time" of all the threads being used by the Store.exe process will reveal one thread using the majority of the processor time.

A categorized view is defined as a view set on a folder in which its contents are sorted or grouped by in some manner (for example, sorted by the From: field). This sorting or grouping can be in ascending or descending order. When a client sets this type of view on a folder, the information store creates a new table in the Exchange database that contains the data needed to display this view.

In this case, when the information store built the Exchange database table, the contents were being sorted in a descending order. The Exchange database engine needs to detect a terminator to know it is has processed all the data, and in this case, the Exchange database engine was searching for the wrong terminator. Because this terminator did not exist, the same portion of the code was being executed repeatedly causing the information store process to utilize high percentages of the system processor and causing the appearance of a hung client for the user who was trying to enter this folder.

To resolve this problem, obtain the latest service pack for Exchange Server version 5.5. For more information, please see the following article in the Microsoft Knowledge Base:

Microsoft has confirmed this to be a problem in Microsoft Exchange Server versions 5.0 and 5.5

A supported fix is now available, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next service pack that contains this fix. Contact Microsoft Technical Support for more information.