You can use Microsoft Office SharePoint Server 2007 (MOSS 2007) caching options to optimize the performance of your sites. MOSS 2007 uses ASP.NET 2.0 caching options as well as caching functionality that the Office team designed specifically for MOSS.
The caching topics describe caching technologies available in MOSS 2007 and how and when to configure caching options to maximize performance and reduce latency. You can customize caching at the page level through output caching; customize caching options for individual objects such as Web Parts, navigation actions, and site map provision through object caching; and control if, how, and when your site uses disk-based caching to reduce latency and improve rendering times for image, sound files, and custom code such as cascading style sheets (.css) and JavaScript (.js) files. The following table shows the types of caching available in MOSS 2007 and what they do.
Output Caching and Cache Profiles
Individual page level
Includes extending caching using VaryByCustomString
Object Caching
Individual Web Part control, field control, and content level
Includes cross-list query caching and navigation caching
Disk-based Caching for Binary Large Objects
Individual binary large object (BLOB) level and caches images, sound, movies, and code
Supports .gif, .jpg, .js, .css, and other image, sound, and code files that are stored as binary large objects
By building cache-aware controls, extending caching in ways appropriate for your site deployment, building navigation providers that always use the object cache, creating content queries that use the Content By Query cache, and creating server controls for your master page and page layouts that minimize database roundtrips, you can vastly improve the performance of your MOSS deployment.
Developers should note that MOSS supplies dedicated caches for navigation nodes and content returned from potentially expensive retrieval operations such as standard WSS queries run by using an SPQuery object and cross-site queries run by using an SPSiteDataQuery object.
Although MOSS 2007 doesn't enable you to use ASP.NET output caching directives in the same way you can in a standard ASP.NET page, it provides a more robust framework to achieve the same results.
If you try to browse to a site with a site collection that has more than 10,000 ACL cache entries, Office SharePoint Server 2007 may disable output caching and you may receive the following error message:
Attempt to release mutex not owned by caller. (Exception from HRESULT: 0x00000120)
To fix this issue, download and install the April 2009 content update as described in Knowledge Base article 968859.