Cluster service leaks memory when the service handles state change notifications in Windows Server 2008 R2 or Windows Server 2008

Consider the following scenario:

• You have a failover cluster node that is running Windows Server 2008 R2 or Windows Server 2008.
• Some cluster-aware clients register for notifications to obtain various state changes.
  
  Note The state changes include online and offline state changes for a resource, registry changes, node additions, and property changes.

In this scenario, the memory usage of the Cluster service may keep increasing. After a while, the available memory is exhausted on the cluster node. Therefore, some applications or services that are running on the cluster node crash or stop responding.

For example, this issue occurs in an environment that has Microsoft System Center Operations Manager 2007 and Microsoft Exchange Server Cluster Continuous Replication (CCR) installed. In this scenario, the MonitoringHost.exe process in System Center Operations Manager 2007 is the cluster-aware client that pulls state change notifications.

This issue occurs because the Cluster service does not manage the server-side threads for state change notifications well.

Cluster-aware clients can register for notifications to obtain various state changes. Dedicated threads are created on the client and on the server (the Cluster service) in the notification port registration process. The client thread pulls notifications from the server thread. If the client thread is terminated, and if the Cluster service is not informed, the Cluster service continues to save these notifications for the nonexistent client thread. Therefore, the memory usage of the Cluster service keeps increasing.

To resolve this issue, install the following hotfix package on the affected failover cluster node that is running Windows Server 2008 R2 or Windows Server 2008.

After you install the following hotfix package, the Cluster service can automatically detect whether the client exists when the service manages the server threads for state change notifications. The server threads automatically return if the Cluster service detects that the client thread does not exist.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft website: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

To apply this hotfix, you must be running one of the following operating systems:

• Windows Server 2008 R2
• Windows Server 2008 R2 Service Pack 1 (SP1)
• Windows Server 2008 Service Pack 2 (SP2)

For more information about how to obtain a Windows Server 2008 R2 service pack, click the following article number to view the article in the Microsoft Knowledge Base:

Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The global version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.

Windows Server 2008 R2 file information notes

Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.

• The files that apply to a specific product, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.
  Collapse this tableExpand this table

  Version	Product	SR_Level	Service branch
  6.1.760 0 . 20xxx	Windows Server 2008 R2	RTM	LDR
  6.1.760 1 . 21xxx	Windows Server 2008 R2	SP1	LDR

• The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For all supported x64-based versions of Windows Server 2008 R2

For all supported IA-64–based versions of Windows Server 2008 R2

For all supported Windows Server 2008 X86

For all supported Windows Server 2008 IA64

For all supported Windows Server 2008 x64

To work around this issue, restart the Cluster service.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: For more information about how to create a notification port, visit the following MSDN website:
For more information about the CreateClusterNotifyPort function, visit the following MSDN website:
For more information about the CloseClusterNotifyPort function, visit the following MSDN website:

Additional file information

Additional file information for Windows Server 2008 R2

Additional files for all supported x64-based versions of Windows Server 2008 R2

Additional files for all supported IA-64–based versions of Windows Server 2008 R2

Additional file information for Windows Server 2008

Additional files for all supported Windows Server 2008 X86

Additional files for all supported Windows Server 2008 IA64

Additional files for all supported Windows Server 2008 x64