Exchmem Heaps Indicating Performance Issue

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at https://go.microsoft.com/fwlink/?linkid=34707.]  

Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool has analyzed the Exchmem Heap performance counters under the MSExchangeIS performance object to determine whether performance on the Exchange server has decreased. The Exchange Server Analyzer Tool reports on the Exchmem counters as follows:

• If the number of Exchmem: Number of heaps with memory errors is more than zero, the Exchange Server Analyzer reports a warning. If this value is more than five, the Exchange Server Analyzer reports an error.

• If the number of Exchmem: Number of memory errors is more than 500, the Exchange Server Analyzer reports an error.

• If the number of Exchmem: Number Additional Heaps is more than three, the Exchange Server Analyzer reports an error.

The Store.exe process uses its own heap allocation mechanism and structures. These are called Exchmem. At startup, the Store.exe process creates several Exchmem heaps. Store.exe does not increase the number of heaps unless the existing number is either fully used or is fragmented to a point where an allocation cannot find enough contiguous memory to succeed.

If there is a memory utilization problem or internal fragmentation (that is, fragmentation in the Exchmem heaps, which reside inside the Exchange store's virtual memory space), the Store.exe process creates new Exchmem heaps.

Generally, if the Store.exe process must repeatedly create additional heaps, the overall Exchange store virtual memory becomes fragmented or depleted. By tracking the counters that are listed above, you can determine whether the Exchmem heaps are a source of the problem or if they decrease in performance as the heaps become fragmented.

To correct the warning or error

• Download and install the latest Exchange store updates.

  • For the latest Exchange Server 2003 downloads, see the Downloads for Exchange Server 2003 Web site (https://go.microsoft.com/fwlink/?LinkId=25097).

  • For the latest Exchange 2000 Server downloads, see the Downloads for Exchange 2000 Server Web site (https://go.microsoft.com/fwlink/?LinkId=33457).

• Download and install the latest updates for all applications that are running in the Store.exe process. Sometimes third-party applications that are running in the Store.exe process can cause heap fragmentation.

• Consider moving user mailboxes from the affected server to another server to reduce server load. For more information, see Move User Mailboxes to Another Server.

• Until you have identified the cause of the problem, you can restart as necessary to reset memory.