Sun Java System Web Server 6.1 SP9 Performance Tuning, Sizing, and Scaling Guide

Cache Information

The cache information section provides statistics on how your file cache is being used. The file cache caches static content so that the server handles requests for static content quickly. For tuning information, seeTuning the File Cache.

Following is an example of how the cache statistics are displayed in perfdump:

enabled             yes
CacheEntries        0/1024
Hit Ratio           0/0 (  0.00%)
Maximum Age         30


If the cache is disabled, the rest of this section is not displayed.


The cache is enabled by default. You can disable it by:


The number of current cache entries and the maximum number of cache entries are both displayed. A single cache entry represents a single URI.


You can set the maximum number of cached entries by:

Hit Ratio (CacheHits / CacheLookups)

The hit ratio gives you the number of file cache hits versus cache lookups. Numbers approaching 100% indicate the file cache is operating effectively, while numbers approaching 0% could indicate that the file cache is not serving many requests.

This setting is not tunable.

Maximum Age

This displays the maximum age of a valid cache entry. The parameter controls how long cached information is used after a file has been cached. An entry older than the maximum age is replaced by a new entry for the same file.


If your web site’s content changes infrequently, you may want to increase this value for improved performance. You can set the maximum age by: