By using the WebSphere Application Server for z/OS support for logging application messages and trace data, you can improve the reliability, availability, and serviceability of any Java application that runs in a WebSphere Application Server for z/OS server. Through this support, your Java application's messages can appear on the MVS master console, in the error log stream, or in the component trace (CTRACE) data set for WebSphere Application Server for z/OS. Your application's trace entries can appear in the same CTRACE data set.