XCON: MTA Performs Excessive Context Switching During Heavy Message Traffic

ID: Q237187

The information in this article applies to:

Microsoft Exchange Server, version 5.5

SYMPTOMS

During heavy X.400 message traffic, the message transfer agent (MTA) may perform excessive context switching, which causes X.400 messages to be delivered more slowly through the Exchange Server computer. Context switching can be monitored using the following Performance Monitor counter:

Object: System
Counter: Context Switches/sec.

RESOLUTION

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

Q191014 XGEN: How to Obtain the Latest Exchange Server 5.5 Service Pack

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 5.5. This problem was first corrected in Exchange Server 5.5 Service Pack 3. When you apply the fix, the following registry key is created:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Messaging Subsystem\Applications\EMSMTA

The following registry value is created under the above key:

Value Name: UseMHEAPMgr
Data Type: REG_DWORD
Value: 1

Additional query words: throughput slow performance exchmem

Keywords : exc55 EXC55SP3Fix
Version : winnt:5.5
Platform : winnt
Issue type : kbbug