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	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 Description

LongJVMPauseDetector(IgniteLogger log)

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	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

Class LongJVMPauseDetector

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_JVM_PAUSE_DETECTOR_THRESHOLD

DFLT_JVM_PAUSE_DETECTOR_PRECISION

DFLT_JVM_PAUSE_DETECTOR_LAST_EVENTS_COUNT

Constructor Detail

LongJVMPauseDetector

Method Detail

start

stop

enabled

getLastWakeUpTime

getLastLongPause

toString