com.hazelcast.internal.diagnostics

Class MemberHeartbeatPlugin

java.lang.Object

com.hazelcast.internal.diagnostics.DiagnosticsPlugin

com.hazelcast.internal.diagnostics.MemberHeartbeatPlugin

public class MemberHeartbeatPlugin
extends DiagnosticsPlugin

A diagnostics plugin that checks the quality of member/member heartbeats.

Normally, heartbeats are sent at a fixed frequency, but if there is a deviation in this frequency, it could indicate problems.

Field Summary

Fields

Modifier and Type	Field and Description
static HazelcastProperty	MAX_DEVIATION_PERCENTAGE The maximum allowed deviation.
static HazelcastProperty	PERIOD_SECONDS The period in seconds the MemberHeartbeatPlugin runs.

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

logger

Constructor Summary

Constructors

Constructor and Description
MemberHeartbeatPlugin(NodeEngineImpl nodeEngine)

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 the MemberHeartbeatPlugin runs.

This plugin is very cheap to use.

This plugin will only output if there is the max deviation is exceeded.

Setting the value high will lead to not seeing smaller deviations. E.g if this plugin runs every minute, then it will not see a lot of small deviations. The default of 10 seconds is ok since it will not generate too much overhead and noise and in most cases it is the big outliers we are interested in.

If set to 0, the plugin is disabled.

MAX_DEVIATION_PERCENTAGE

public static final HazelcastProperty MAX_DEVIATION_PERCENTAGE

The maximum allowed deviation. E.g. if the interval of member/member heartbeats is 5 seconds, a 100% deviation will be fine with heartbeats arriving up to 5 seconds after they are expected. So a heartbeat arriving at 9 seconds will not be rendered, but a heartbeat received at 11 seconds, will be rendered.

Constructor Detail

MemberHeartbeatPlugin

public MemberHeartbeatPlugin(NodeEngineImpl nodeEngine)

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