Long running Java process resource consumption monitoring , leak detection and GC tuning
For easily monitoring the JVM metrics there is no better tool than Java VisualVM or its older counterpart JConsole; These two tools comes with the Java JDK. So it is absolutely necessary that you copy a JDK version to some temp directory in which your server runs. {Make sure that you do not install the JDK / put the java executable in the path.} Before going in JVM monitoring, it is essential to understand a little about Java's memory model. Note - This article is written with HotSpot JVM in mind,which is one of the most commonly used one ; implemented by OpenJDK and Oracle - formerly from Sun. This is not the only one , notable being JRockit and others ; and some details would change with a different JVM. When you are running a Java Process in a Server you allocate the Memory for the Java Virtual Machine. This memory is split to process heap { what you give withe the Xmx Xms command}where it is again subdivided on generational basis (Young, Old) and the PermGen -...