Tuning
Youcan set the maximum size of the DNS cache in the Admin Console in the Maximum Cache
Sizeeld on the conguration's Performance tab ⇒DNS sub tab, under DNS Cache Settings.
Toset it using the command-line-interface, use wadm set-dns-cache-prop and set the
max-entriesproperty. The default cache size is 1024. The value range is 2-32768.

HitRatio (Cache Hits / Cache Lookups)

Thehit ratio in perfdump displays the number of cache hits compared to the number of cache
lookups.You can compute this number using the statistics in the Admin Console by dividing
theTotal Cache Hits by the sum of the Total Cache Hits and the Total Cache Misses.
Thissetting is not tunable.

AsyncDNS Enabled/Disabled

AsyncDNS enabled/disabled displays whether the server uses its own asynchronous DNS
resolverinstead of the operating system's synchronous resolver. By default, Async DNS is
disabled.If it is disabled, this section does not appear in perfdump. To enable it using the Admin
Console,on the conguration's Performance tab ⇒DNS tab, under DNS Lookup Settings,
selectAsynchronous DNS. To enable it using the command-line interface, use wadm
set-dns-propand set the async property to true.
JavaVirtual Machine (JVM) Information
JVMstatistics are displayed through the Admin Console, the CLI, and stats-xml only. They
arenot shown in perfdump.
Thefollowing table shows an example of the JVM statistics displayed in the Admin Console:
TABLE2–7 JavaVirtual Machine( JVM) Statistics
VirtualMachine Name JavaHotSpotTM Server VM
VirtualMachine Vendor SunMicrosystems Inc.
VirtualMachine Version 1.5.0_06-b05
HeapMemory Size 5884856
ElapsedGarbage Collection Time (milli seconds) 51
PresentNumber of Classes Loaded 1795
TotalNumber of Classes Loaded 1795
UsingMonitoringData to TuneYour Server
SunJavaSystem Web Server 7.0 Update 1 Performance Tuning,Sizing, and Scaling Guide •70