com.palantir.opensource.sysmon.linux
Class LinuxEntropyLevelJMXWrapper

java.lang.Object
  java.lang.Thread
      com.palantir.opensource.sysmon.linux.LinuxEntropyLevelJMXWrapper

All Implemented Interfaces:

Monitor, Runnable

public class LinuxEntropyLevelJMXWrapper
extends Thread
implements Monitor

Monitors entropy pools that feed secure random number generation.

Entropy pool size is reported in bytes and is read out of the /proc filesystem on a configurable period.

JMX Data Path

sysmon.linux.beanpath:type=EntropyLevel

Configuration parameters

Note that any value not set in the config file will use the default value.

Config Key	Description	Default Value	Constant
sysmon.linux.entropyLevel.period	Period, in seconds, between checks of the entropy pool	10	CONFIG_KEY_ENTROPY_LEVEL_PERIOD

See Also:

Lifecycle documentation, the random(4) man page for more information on entropy pools

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

static String	CONFIG_KEY_ENTROPY_LEVEL_PERIOD Set this value in the configuration file to set how often (in seconds) the entropy levels are checked.
static int	DEFAULT_ENTROPY_LEVEL_PERIOD Default value for how often (in seconds) the entropy levels are checked.
static String	OBJECT_NAME Path where this bean publishes its values.

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

LinuxEntropyLevelJMXWrapper(Properties config)
Constructs a new LinuxEntropyLevel object.

Method Summary

void	run()
void	startMonitoring() Start background thread to monitor entropy levels.
void	stopMonitoring() Signals for the background thread to shutdown and waits for its execution to finish.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Field Detail

CONFIG_KEY_ENTROPY_LEVEL_PERIOD

public static final String CONFIG_KEY_ENTROPY_LEVEL_PERIOD

Set this value in the configuration file to set how often (in seconds) the entropy levels are checked. Key: "sysmon.linux.entropyLevel.period"

See Also:

for default value for the configuration parameter., Constant Field Values

DEFAULT_ENTROPY_LEVEL_PERIOD

public static final int DEFAULT_ENTROPY_LEVEL_PERIOD

Default value for how often (in seconds) the entropy levels are checked. Default: 10

See Also:

for instructions on overriding the default value., Constant Field Values

OBJECT_NAME

public static final String OBJECT_NAME

Path where this bean publishes its values. Path: ":type=EntropyLevel"

See Also:

Constant Field Values

Constructor Detail

LinuxEntropyLevelJMXWrapper

public LinuxEntropyLevelJMXWrapper(Properties config)
                            throws LinuxMonitoringException

Constructs a new LinuxEntropyLevel object. You must call startMonitoring() to start the background thread that will continually update the entropy pool values. Note that the constructor will do a single read of the entropy to verify that everything will work in the background thread. Therefore, constructing one of these object is a valid way to take a one-time reading of the entropy pool size.

Parameters:

config - configuration for this JMX wrapper. Passing null or an empty Properties object will just use the default config values.

Throws:

LinuxMonitoringException - on configuration or data read error.

Method Detail

startMonitoring

public void startMonitoring()

Start background thread to monitor entropy levels.

Specified by:

startMonitoring in interface Monitor

Throws:

LinuxMonitoringException

stopMonitoring

public void stopMonitoring()
                    throws InterruptedException

Signals for the background thread to shutdown and waits for its execution to finish.

Specified by:

stopMonitoring in interface Monitor

Throws:

InterruptedException - if the calling thread is interrupted while waiting for the background thread to Thread.join().

run

public void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread