com.hazelcast.internal.diagnostics

Class EventQueuePlugin

java.lang.Object

com.hazelcast.internal.diagnostics.DiagnosticsPlugin

com.hazelcast.internal.diagnostics.EventQueuePlugin

public class EventQueuePlugin
extends DiagnosticsPlugin

The EventQueuePlugin checks the event queue and samples the event types if the size is above a certain threshold.

This is very useful to figure out why the event queue is running full.

Field Summary

Fields

Modifier and Type	Field and Description
static HazelcastProperty	PERIOD_SECONDS The period in seconds this plugin runs.
static HazelcastProperty	SAMPLES The number of samples to take from the event queue.
static HazelcastProperty	THRESHOLD The minimum number of events in the queue before it is being sampled.

Fields inherited from class com.hazelcast.internal.diagnostics.DiagnosticsPlugin

logger

Constructor Summary

Constructors

Constructor and Description
EventQueuePlugin(ILogger logger, StripedExecutor eventExecutor, HazelcastProperties props)
EventQueuePlugin(NodeEngineImpl nodeEngine, StripedExecutor eventExecutor)

Method Summary

Modifier and Type	Method and Description
long	getPeriodMillis() Returns the period of executing the monitor in millis.
void	onStart()
void	run(DiagnosticsLogWriter writer)

Methods inherited from class java.lang.Object

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

Field Detail

PERIOD_SECONDS

public static final HazelcastProperty PERIOD_SECONDS

The period in seconds this plugin runs.

With the EventQueuePlugin one can see what is going on inside the event queue. It makes use of sampling to give some impression of the content.

If set to 0, the plugin is disabled.

THRESHOLD

public static final HazelcastProperty THRESHOLD

The minimum number of events in the queue before it is being sampled.

SAMPLES

public static final HazelcastProperty SAMPLES

The number of samples to take from the event queue. Increasing the number of samples gives more accuracy of the content, but it will come at greater price.

Constructor Detail

EventQueuePlugin

public EventQueuePlugin(NodeEngineImpl nodeEngine,
                        StripedExecutor eventExecutor)

EventQueuePlugin

public EventQueuePlugin(ILogger logger,
                        StripedExecutor eventExecutor,
                        HazelcastProperties props)

Method Detail

getPeriodMillis

public long getPeriodMillis()

Description copied from class: DiagnosticsPlugin

Returns the period of executing the monitor in millis.

If a monitor is disabled, 0 is returned.

If a monitor should run only once, a negative value is returned. This is useful for 'static' monitors like the SystemPropertiesPlugin that run at the beginning of a log file but their contents will not change.

Specified by:

getPeriodMillis in class DiagnosticsPlugin

Returns:

the period in millis.

onStart

public void onStart()

Specified by:

onStart in class DiagnosticsPlugin

run

public void run(DiagnosticsLogWriter writer)

Specified by:

run in class DiagnosticsPlugin