This event indicates that the Microsoft Exchange Server 2010 Mailbox Assistants are using a large amount of RAM. This alert may indicate that a memory bottleneck or a memory leak exists.

In this scenario, the Exchange 2010 mailbox server may be slow to respond to user requests. All activities performed by the Mailbox Assistants may take longer to process or may experience intermittent failures.

The Assistants Infrastructure is part of the hosting application installation on servers that host the Mailbox server role. The Assistants Infrastructure is the component in Exchange 2010 that separates message processing business logic from the information store. The separation of business logic from the store has the advantage of reducing the load on the store and makes it easier to implement changes in business logic design and testing. This business logic includes the following features:

• E-mail retention
  
  
• Resource scheduling
  
  
• Automated out-of-office messages
  
  
• Automated calendaring features
  
  

To handle business logic processing, the Assistants Infrastructure makes use of event-based assistants known as Mailbox Assistants. Event-based assistants process tasks based on events from the information store, and time-based assistants process tasks based on schedules. If insufficient memory is available, the assistants may be unable to run.

To resolve this problem, do one or more of the following:

• Review the Application log and System log on your Exchange 2010 servers for related events. For example, events that occur immediately before and after this event may provide more information about the root cause of this error.
  
  
• To review detailed information about the cause of this alert, use the Operations Console in Operations Manager. For more information, see the "Introduction" section to this topic.
  
  
• Examine the event log entries for each Assistants Infrastructure and for each corresponding Assistant to determine whether any exceptions exist. You may have to increase diagnostics logging to generate additional events. Any event that is generated in the Application includes the exception type. You can use the information to help determine the cause of the excessive CPU usage.
  
  
• Collect performance information for all the Assistant Infrastructure counters by using the MSExchange Assistants object. Also, collect performance data for each Assistant object. There is one instance for every hosting application per database on the server. The instance name contains the service name of the hosting application's service together with the database name. Additionally, there is a total instance for each hosting application. The "total" captures consolidated values for every counter for all assistants that are hosted by the application.
  
  
• If the Mailbox server is overloaded, add additional Mailbox servers, as required.
  
  
• Resolve your issue by using self-support options, assisted support options, and other resources. You can access these resources from the Exchange Server Solutions Center. From this page, click Self-Support Options in the navigation pane to use self-help options. Self-help options include searching the Microsoft Knowledge Base, posting a question at the Exchange Server forums, and others. Alternatively, in the navigation pane, you can click Assisted Support Options to contact a Microsoft support professional. Because your organization may have a specific procedure for directly contacting Microsoft Technical Support, be sure to review your organization's guidelines first.
  
  

If you are not already doing so, consider running the Exchange tools created to help you analyze and troubleshoot your Exchange environment. These tools can help make sure that your configuration aligns with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. To run these tools, go to the Toolbox node of the Exchange Management Console. To learn more about these tools, see Managing Tools in the Toolbox.