While a Web service is enabled, you can set only the serviceFaultLevel and serviceLoggingLevel properties. To set the other properties, the Web service must be disabled. Any changes to the other properties take effect when the Web service is enabled.
When a Web service is enabled, the WSA begins a startup process that involves establishing the Web service's connection pool. Establishing the Web service's connection pool involves pre-establishing any AppServer connections that will be cached to handle incoming client requests more efficiently.