When Microsoft BizTalk Server 2004 is installed, the BizTalk Service may appear to stop responding. Additionally, you may receive out-of-memory error messages. This problem may occur even though you have sufficient available memory for the BizTalk Server 2004 process when you review process memory in Windows Performance Monitor or in Windows Task Manager.

This out-of-memory problem is caused by memory fragmentation.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. 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 Web site: 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

You must have BizTalk Server 2004 installed to apply this hotfix.

Restart requirement

You do not have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.Microsoft BizTalk Server 2004, x86Note Because of file dependencies, the most recent hotfix that contains these files may also contain additional files.

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

To enable this hotfix, the operating system that is installed on the computer must support the Low Fragmentation Heap algorithm. Microsoft Windows XP and Microsoft Windows Server 2003 support the Low Fragmentation Heap algorithm.

Heap fragmentation occurs when available memory is broken into small, noncontiguous blocks. When this behavior occurs, memory allocation can fail even though sufficient memory is in the heap to satisfy the request. This problem occurs because no one block of memory is large enough to satisfy the allocation request.

For applications that have a low memory usage, the standard heap is sufficient. Allocations will not fail because of heap fragmentation. However, if the application allocates memory frequently and uses a variety of allocation sizes, memory allocation can fail because of heap fragmentation. Low fragmentation heap (LFH) is built on the existing heap. However, as the name implies, LFH reduces fragmentation of the heap.

To enable LFH in operating systems that support the Heap API, you must call the supporting HeapSetInformation API function that this change in BizTalk Server enables. For more information, visit the following Microsoft Developer Network (MSDN) Web site: Heap fragmentation may occur under many different circumstances in BizTalk Server. The number and the size of the documents that BizTalk Server may process is not the determining factor when you evaluate if this change will work in a particular environment. Heap fragmentation occurs in a process that is based on the allocation patterns of the process in a specific heap.

When you test BizTalk Server after fragmentation has occurred, the two heaps that typically show the most fragmentation are the Microsoft Data Access Components (MDAC) heaps and the default heap. For the default BizTalk Server heap, LFH is only enabled for this heap. No other heaps are affected. Therefore, an LFH heap may not make a change in every situation.

For more information about the Low Fragmentation Heap algorithm in Windows 2000, click the following article number to view the article in the Microsoft Knowledge Base: For more information, click the following article number to view the article in the Microsoft Knowledge Base: