com.espertech.esper.metrics.codahale_metrics.metrics.util
Class DeathRattleExceptionHandler

java.lang.Object
  com.espertech.esper.metrics.codahale_metrics.metrics.util.DeathRattleExceptionHandler

All Implemented Interfaces:

java.lang.Thread.UncaughtExceptionHandler

public class DeathRattleExceptionHandler
extends java.lang.Object
implements java.lang.Thread.UncaughtExceptionHandler

When a thread throws an Exception that was not caught, a DeathRattleExceptionHandler will increment a counter signalling a thread has died and print out the name and stack trace of the thread.

This makes it easy to build alerts on unexpected Thread deaths and fine grained used quickens debugging in production.

You can also set a DeathRattleExceptionHandler as the default exception handler on all threads, allowing you to get information on Threads you do not have direct control over.

Usage is straightforward:

 final Counter c = Metrics.newCounter(MyRunnable.class, "thread-deaths");
 Thread.UncaughtExceptionHandler exHandler = new DeathRattleExceptionHandler(c);
 final Thread myThread = new Thread(myRunnable, "MyRunnable");
 myThread.setUncaughtExceptionHandler(exHandler);
 

Setting the global default exception handler should be done first, like so:

 final Counter c = Metrics.newCounter(MyMainClass.class, "unhandled-thread-deaths");
 Thread.UncaughtExceptionHandler ohNoIDidntKnowAboutThis = new DeathRattleExceptionHandler(c);
 Thread.setDefaultUncaughtExceptionHandler(ohNoIDidntKnowAboutThis);
 

Constructor Summary

DeathRattleExceptionHandler(Counter counter)
Creates a new DeathRattleExceptionHandler with the given Counter.

Method Summary

void	uncaughtException(java.lang.Thread t, java.lang.Throwable e)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DeathRattleExceptionHandler

public DeathRattleExceptionHandler(Counter counter)

Creates a new DeathRattleExceptionHandler with the given Counter.

Parameters:

counter - the Counter which will be used to record the number of uncaught exceptions

Method Detail

uncaughtException

public void uncaughtException(java.lang.Thread t,
                              java.lang.Throwable e)

Specified by:

uncaughtException in interface java.lang.Thread.UncaughtExceptionHandler