How would you troubleshoot a hang issue in a Java application?

How would you troubleshoot a hang issue in a Java application?

If the application appears to be hung and the process appears to be idle, then the first step is to try to get a thread dump. If the application console is available, then press Control+\ (on Oracle Solaris or Linux), or Control+Break (on Windows) to cause the HotSpot VM to print a thread dump.

How do you know if a process is hung?

You can run “strace -p ” command to check if the process is hung or not. If it is running it would issue system calls and based on what system call you can also determine if it is waiting for some IO or trying to read/write a file or waiting for some other child process.

How do you debug a hanging process?

How do you debug a hanging process?

1. Run the program that is freezing or hanging, and that you wish to debug.
2. Run the Debugging Tool for Windows.
3. Click on the File menu, and select Attach to a Process.
4. Find the process for the program which you wish to debug.
5. The command window should automatically open.

How do you kill a hanged process?

Simply type the PID of the process you wish to kill and press enter. It will ask for a Kill signal to send. To kill the process nicely use the default 15 – to kill it right away “Do not pass go, do not collect $200” use 9.

What could be the root cause for the thread dead lock in the application?

A deadlock occurs when two or more threads in the JVM form a cyclic dependency with each other. “The JVM is not nearly as helpful in resolving deadlocks as database servers are. When a set of Java threads deadlock, that’s the end of the game. Depending on what those threads do, the application may stall completely.”

How do I debug a Windows hung process?

To install and use Debugging Tool for Windows

1. Run the program that is freezing or hanging, and that you wish to debug.
2. Run the Debugging Tool for Windows.
3. Click on the File menu, and select Attach to a Process.
4. Find the process for the program which you wish to debug.
5. The command window should automatically open.

What is hung process?

In computing, a hang or freeze occurs when either a process or system ceases to respond to inputs. A typical example is when computer’s graphical user interface (such as Microsoft Windows) no longer responds to the user typing on the keyboard or moving the mouse.

How do you check if a process is killed in Linux?

To verify that the process has been killed, run the pidof command and you will not be able to view the PID. In the above example, the number 9 is the signal number for the SIGKILL signal.

Why do process hang?

In computing, a hang or freeze occurs when either a process or system ceases to respond to inputs. The fundamental reason is typically resource exhaustion: resources necessary for some part of the system to run are not available, due to being in use by other processes or simply insufficient. …

How do I find hung processes in Windows?

Identify the hung or suspended process, the Overview or CPU tab and right-click on it. In the context menu, you will see Analyze Wait Chain. Windows 10/8 now allows you to analyze Wait Chain right from the Windows Task Manager itself, apart from the Resource Monitor.

How do I kill a hanged process in Windows?

Method 1: Via Task Manager

1. Press “Ctrl + Alt + Delete” Key or “Window + X” Key and click the Task Manager option.
2. Click on the “Processes” Tab.
3. Select a process you want to kill, and perform one of the actions below. Press the Delete key. Click on the End task button. Right-click on the process, and click on End task.

What are hanging processes and how to troubleshoot them?

This chapter provides information and guidance on some specific procedures for troubleshooting hanging or looping processes. Problems can occur that involve hanging or looping processes. A hang can occur for many reasons but often stems from a deadlock in application code, API code, or library code.

What should I do if I have a system hang?

So to recap, here are the basic steps to follow regarding a complete system hang: Is this a hard or soft hang? If this is a hard hang, then the odds are that there is an underlying hardware issue, so contact your hardware vendor. Check the Event logs for any events in the System Log at the time of the hang.

How to troubleshoot a hanging process in jstack?

In that case use the jstack utility (see 2.11 jstack Utility ) to obtain a thread dump. Use the jstack -F pid option to force a stack dump of the hung process. This also applies in the case where the application is not accessible or the output is directed to an unknown location.

How to troubleshoot hanging or looping processes in Java?

If the Java process is started with the -XX:+PrintClassHistogram command-line option, then the Ctrl-Break handler will produce a heap histogram. If a thread dump can be obtained, then a good place to start is the thread stacks of the threads that are in the runnable state.