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

DNS Cache Information

The DNS cache caches IP addresses and DNS names. Your server’s DNS cache is disabled by default. Statistics are displayed in the DNS Statistics for Process ID page under Monitor in the Server Manager.


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


By default, the DNS cache is off. You can enable DNS caching by:

CacheEntries (CurrentCacheEntries / MaxCacheEntries)

The number of current cache entries and the maximum number of cache entries. A single cache entry represents a single IP address or DNS name lookup. The cache should be as large as the maximum number of clients that will access your web site concurrently. Note that setting the cache size too high will waste memory and degrade performance.


You can set the maximum size of the DNS cache by:

HitRatio (CacheHits / CacheLookups)

The hit ratio displays the number of cache hits versus the number of cache lookups.

This setting is not tunable.