Package org.apache.hadoop.util

Enum SignalLogger

java.lang.Object

java.lang.Enum<SignalLogger>

org.apache.hadoop.util.SignalLogger

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<SignalLogger>

@Private
@Unstable
public enum SignalLogger
extends java.lang.Enum<SignalLogger>

This class logs a message whenever we're about to exit on a UNIX signal. This is helpful for determining the root cause of a process' exit. For example, if the process exited because the system administrator ran a standard "kill," you would see 'EXITING ON SIGNAL SIGTERM' in the log.

Enum Constant Summary

Enum Constants

Enum Constant	Description
INSTANCE

Method Summary

Modifier and Type	Method	Description
void	register(org.slf4j.Logger log)	Register some signal handlers.
static SignalLogger	valueOf(java.lang.String name)	Returns the enum constant of this type with the specified name.
static SignalLogger[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

INSTANCE

public static final SignalLogger INSTANCE

Method Detail

values

public static SignalLogger[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (SignalLogger c : SignalLogger.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static SignalLogger valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null

register

public void register(org.slf4j.Logger log)

Register some signal handlers.

Parameters:

log - The log4j logfile to use in the signal handlers.