Server That Runs Windows SharePoint Services May Run Low on Memory Resources (826803)


The information in this article applies to:

  • Microsoft Windows SharePoint Services

SYMPTOMS

A server that is running Microsoft Windows SharePoint Services may occasionally run low on memory. As a result, the server may stop responding (hang).

CAUSE

This behavior may occur if all the following conditions are true:
  • You have more than one virtual server configured on the server that runs Windows SharePoint Services.

    -and-
  • You use Web part components in the Windows SharePoint Services Web sites.

    -and-
  • The server suddenly uses too much memory. For example, this may occur if you upload a large document to the server.
This behavior occurs because on a server where more than one virtual server is configured, the ASP.Net cache may be configured to use more memory than what is available. Because the Microsoft Office 2003 Web part framework uses this cache, the server may run with low memory. If the server is configured with a static virtual memory size, virtual memory may become exhausted, and the server may stop responding.

RESOLUTION

To resolve this behavior, manually configure the ASP.NET memory usage so that it is not greater than the available physical (not virtual) memory on the server. To do this, follow these steps:
  1. Click Start, point to Administrative Tools, and then click Internet Information Services (IIS) Manager.
  2. Expand Application Pools.
  3. Right-click an application pool (for example, right-click DefaultAppPool), and then click Properties.
  4. On the Recycling tab, click to select the Maximum used memory (in megabytes) check box, and then type a value that is less than the physical memory in the server.

    Microsoft recommends a value that is approximately 60 percent of the physical memory. For example, on a server with 512 MB of physical memory, type 310. If you are configuring two application pools, set each value to approximately 30 percent of the physical memory. Additionally, do not configure the maximum used memory value greater than 800 MB when you use a 2-gigabyte (GB) address space. If the server's memory address space is 3 GB, you can configure a maximum memory limit for the worker process of up to 1,800 MB.
  5. Click Apply, and then click OK.
  6. Follow steps 3 through 5 to configure ASP.NET memory usage for each application pool.

WORKAROUND

To work around this issue, run the IISreset command from a command prompt to restart Microsoft Internet Information Services. This releases memory resources on the server.

MORE INFORMATION

The ASP.NET cache reduces the number of items in the cache when physical memory becomes low. It uses the following two metrics:
  • The physical memory available.

    If this number falls below 10 percent, the cache removes items aggressively. This value should be greater than the limit where the operating system starts paging data to the hard disk.
  • The per-process private memory bytes used.

    This setting prevents ASP.NET worker processes from restarting when it is used in Windows 2000. To use this in Windows Server 2003, you must configure the Maximum used memory (in megabytes) and not the Maximum virtual memory (in megabytes) option.
The cache usage is based on the maximum allocated memory setting for the IIS application pool. Stress testing has indicated that a setting of about 60 percent total physical memory provides optimum performance. If you have two processes, assign each process about 30 percent of physical memory. If you do not assign sufficient memory for the caching requirements, you must add additional physical memory to the server.

For more information about how to deploy, configure, and administer SharePoint Portal Server and Windows SharePoint Services, see the Microsoft Office SharePoint Portal Server 2003 Administration Guide. The Microsoft Office SharePoint Portal Server 2003 Administration Guide (Administrator's Help.chm) is located in the Docs folder in the root folder of the SharePoint Portal Server 2003 CD.

For more information about SharePoint Portal Server and Windows SharePoint Services, visit the following Microsoft Web site:

http://www.microsoft.com/sharepoint/default.asp

Modification Type:MinorLast Reviewed:1/9/2006
Keywords:kbprb KB826803 kbAudITPRO
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