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Measures reported by MossPubTest
Object caching
Office SharePoint Server 2007 supports caching of certain page items, such as navigation data and data accessed through cross-list queries. Caching page items reduces the requirement to retrieve field data from the database every time a page is rendered. The caching system also caches complete field data for a page, excluding data for any Web Part controls on the page.
Object cache tuning:
The size of the object caching is set at 100 MB per site collection by default. However, you can edit this setting for each site collection to fit the characteristics of the Web site. You can use a set of performance counters to tune the size of the object cache. The name of the performance counter object is SharePoint Publishing Cache Object. Based on the cache hit ratio and the change in object discard counters, you can set the object cache size accordingly.
Start with a low value (for example, 200 MB) and monitor the cache hit ratio and object discard counter. A hit ratio greater than 90% and a low object discard rate are generally good signs that the current size is satisfactory. However, you should also measure user response time for key operations to adjust this setting.
If you set the size too large, you might waste valuable memory for the other caches, such as the ASP.NET output cache if it is used. Certain Web Parts, such as the Content Query Web Part, stores their XSLT stylesheets in the output cache. If the object cache size is set too large, ASP.NET might flush output cache memory to make room for it. CPU usage might increase after the flushing. This is especially important for a system that is running on a 32-bit operating system because each worker process is limited to 2 GB application memory space. If you set the object cache size limit too large, the IIS worker process (w3wp) can run out of memory.
The measures
made by this test are as
follows:
| Measurement |
Description |
Measurement
Unit |
Interpretation |
| Publishing_cache_hit_ratio |
Indicates the ratio of hits that are missed on the publishing cache.
|
Percentage |
|
| Total_object_discards |
Indicates the total number of items that have been removed from the publishing cache for the last measurement period due to cache compaction.
|
Number |
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