XADM: Directory Store Stops While Calculating Hierarchy Table

• Microsoft Exchange Server, version 4.0

SYMPTOMS

The Microsoft Exchange Server directory store (DS) may stop responding while calculating the hierarchy table. Through replication, the bad hierarchy may be copied to all other computers running Microsoft Exchange Server, causing them to come down also.

CAUSE

The DS incorrectly searches memory that was not allocated when it looks for the non-existent parent of an orphaned entry in the hierarchy table. The search loop looking for the parent object decrements and dereferences a pointer over and over, eventually getting to non-allocated memory. If this hierarchy table is replicated with orphaned objects, the problem is replicated with it.

WORKAROUND

To work around this problem, obtain the hotfix mentioned below. With the hotfix, the search loop is now checked at each iteration against the record count. If the pointer is invalid, the object is marked as having no parent.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 4.0. This problem was corrected in the latest Microsoft Exchange 4.0 U.S. Service Pack. For information on obtaining the service pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K

Keywords          : kbbug4.00 kbfix4.00.sp4 XADM kbusage
Version           : 4.0
Platform          : WINDOWS
Issue type        : kbbug
Solution Type     : kbfix