As soon as the GWES is installed, it is possible to query a number of things using its web interface. However, it must be made sure to protect these pages from unauthorized use, e.g. by setting a user/password combination in tomcat-users.xml, or by other means. Then it is possible to find the interface at http://host:port/gwes/servlet/GWESOverviewServlet. Here you can
upload new workflow documents (in GridWorkflowDL format);
get a list of all workflows currently in memory or database;
see the details of a specific workflow with statistical and status information (warnings and errors that led to unsuccessful termination of the workflow will appear here);
see a graph of the workflow, even animated when it is executing (c.f. figure 2 below)
test if the GWES is alive and
get documentation.
Furthermore, there are the Tomcat logs where GWES will log its messages, too. Depending on the settings in webapps/gwes/WEB-INF/classes/log4j.properties (e.g. set log4j.logger.net.kwfgrid.gwes.wsactivity to DEBUG for debug logging of Web Service jobs) one can find useful debugging information when something did not work as expected. See the file logs/catalina.out in Tomcat's installation folder.
figure 2: graph of the workflow displayed by GWES' web interface