Basic server monitoring
JMeter comes with an out-of-the-box monitoring controller. This allows you to monitor the general health of the application or web server. These include light-weight web containers such as Jetty, Apache Tomcat, Resin, or fully-stacked, heavier ones such as WebSphere, Weblogic, JBoss, Geronimo, and Oracle OCJ4. Metrics such as active threads, memory, health, and load are gathered and reported in a graphical form. Having such metrics makes it easier to see the relationship between server performance and response time on the clients. Multiple servers can be monitored using a single monitor controller. Although originally designed to work with the Apache Tomcat server (http://tomcat.apache.org/), any servlet container (http://en.wikipedia.org/wiki/Servlet_container) supporting JMX (Java Management Extension) can port the Tomcat status servlet to provide the same information. Providing such ports for other servers goes beyond the scope of this book, so we will stick to...