Sun Java System Web Server 7.0 Update 7 Performance Tuning, Sizing, and Scaling Guide

Async DNS Enabled/Disabled

Async DNS enabled/disabled displays whether the server uses its own asynchronous DNS resolver instead 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 configuration's Performance tab ⇒ DNS tab, under DNS Lookup Settings, select Asynchronous DNS. To enable it using the command-line interface, use wadm set-dns-prop and set the async property to true.