TestingWorld

How to Capture Thread Dump in JVM Let’s see how to capture thread dump of application in java. We can capture it with or without Console. Method to generate Thread dump with Console: 1. On Windows: ·          Press Ctrl-Break in the command console you used to start the IDE  If the console isn't opened (in case you started the IDE using the default desktop icon): launch the IDE using a console window  -Start Command Prompt -go to {netbeans-install-dir}/bin -type nb.exe configure the desktop shortcut to launch the nb.exe instead of netbeans.exe (default) NB7 and higher - just run netbeans.exe from console. If NB is started by shortcut use "--console new" option to open console (netbeans.exe --console new). ·          The thread dump is printed into the command console. 2. Console on Unix, Linux, Mac OS X ·    ...

Thread Dump is another good way to analyse about application behaviour. What is Thread dump? Thread dump is list of threads which are currently active in Virtual machine. Thread dump is very useful when it comes to know below things: 1.        How many threads are active 2.       Total no of threads used in one work flow 3.       Which thread is doing what in application In short we can also define thread dump as a snapshot of state of all threads in a process of application.

                              How to analyse heap dump I have already discussed about heap dump in one of the post. Please refer the link below to read it: http://professionalcurve.blogspot.com/2014/03/heap-dump-how-to-generate-heap-dump.html Now we will see about how to analyze them. There are various tools for reading heap dump. I prefer MAT (Eclipse Memory Analyzer Tool). It is powerful and free tool which can read, parse and analyze them. Before opening heap dump in MAT, let’s focus on some basic things related to it: -          Shallow Size : T he sum of the sizes of all contained primitive data types, as well as the size of the references to other objects -          Retained Heap : The total size of all objects being kept alive by...

Heap dump is important when it’s come to performance testing. Let’s start with what is heap in an application. Heap: Heap is dynamically collective amount of data /memory in partially binary sorted tree structure. But we need to loop up on heap in term of memory. Heap is part of memory where memory for objects assigned dynamically. Heap dump : Heap Dump is snapshot of memory at certain point which contains below mentioned information: -information of java objects -information of java classes or we can define as A heap dump is a textual or binary representation of the Java heap which is usually written to a file.   Heap dump is always helpful to analyze memory leak or high usage of memory of java application. There are various tools which help us to generate the heap dump. We can also generate heap dump without using tools. What we require is JVM (Java Virtual Machine)on system. There are various vendors for JVM but let’s concentrate on Sun JVM. ...