If your site is under heavy load, you can adjust settings to improve performance. The settings are located in the <ATGdir>\Search2008.1\SearchEngine\operating_system\bin\AESoapWaspConfig.xml file.
hts:reuseCount—Number of times to reuse a "keep-alive" connection. This should always be set to 0 to avoid engine thread starvation.
rwTimeout—Length of time in seconds to wait before a read or write operation times out on an active connection. Default is 10.
maxSpareThreads—Number of threads to use in the engine. The default is 10. Increase this setting if you are running Search on a multi-core system and CPU usage is low.
