org.apache.ignite.internal

Class LongJVMPauseDetector

java.lang.Object

org.apache.ignite.internal.LongJVMPauseDetector

public class LongJVMPauseDetector
extends Object

Class for detection of long JVM pauses. It has a worker thread, which wakes up in cycle every PRECISION (default is 50) milliseconds, and monitors a time values between awakenings. If worker pause exceeds the expected value more than THRESHOLD default is 500), the difference is considered as JVM pause, most likely STW, and event of long JVM pause is registered. The values of PRECISION, THRESHOLD and EVT_CNT (event window size, default is 20) can be configured in system or environment properties IGNITE_JVM_PAUSE_DETECTOR_PRECISION, IGNITE_JVM_PAUSE_DETECTOR_THRESHOLD and IGNITE_JVM_PAUSE_DETECTOR_LAST_EVENTS_COUNT accordingly.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_JVM_PAUSE_DETECTOR_THRESHOLD Ignite JVM pause detector threshold default value.
static int	DFLT_JVM_PAUSE_DETECTOR_LAST_EVENTS_COUNT
static int	DFLT_JVM_PAUSE_DETECTOR_PRECISION

Constructor Summary

Constructors

Constructor and Description
LongJVMPauseDetector(IgniteLogger log)

Method Summary

Modifier and Type	Method and Description
static boolean	enabled()
@Nullable IgniteBiTuple<Long,Long>	getLastLongPause()
long	getLastWakeUpTime()
void	start() Starts worker if not started yet.
void	stop() Stops the worker if one is created and running.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_JVM_PAUSE_DETECTOR_THRESHOLD

public static final int DEFAULT_JVM_PAUSE_DETECTOR_THRESHOLD

Ignite JVM pause detector threshold default value.

See Also:

Constant Field Values

DFLT_JVM_PAUSE_DETECTOR_PRECISION

public static final int DFLT_JVM_PAUSE_DETECTOR_PRECISION

See Also:

IgniteSystemProperties.IGNITE_JVM_PAUSE_DETECTOR_PRECISION, Constant Field Values

DFLT_JVM_PAUSE_DETECTOR_LAST_EVENTS_COUNT

public static final int DFLT_JVM_PAUSE_DETECTOR_LAST_EVENTS_COUNT

See Also:

IgniteSystemProperties.IGNITE_JVM_PAUSE_DETECTOR_LAST_EVENTS_COUNT, Constant Field Values

Constructor Detail

LongJVMPauseDetector

public LongJVMPauseDetector(IgniteLogger log)

Parameters:

log - Logger.

Method Detail

start

public void start()

Starts worker if not started yet.

stop

public void stop()

Stops the worker if one is created and running.

enabled

public static boolean enabled()

Returns:

false if IgniteSystemProperties.IGNITE_JVM_PAUSE_DETECTOR_DISABLED set to true, and true otherwise.

getLastWakeUpTime

public long getLastWakeUpTime()

Returns:

Last checker's wake up time.

getLastLongPause

@Nullable
public @Nullable IgniteBiTuple<Long,Long> getLastLongPause()

Returns:

Pair (last long pause event time, pause time duration) or null, if long pause wasn't occurred.

toString

public String toString()

Overrides:

toString in class Object