com.hazelcast.quorum.impl

Class ProbabilisticQuorumFunction

java.lang.Object

com.hazelcast.quorum.impl.AbstractPingAwareQuorumFunction

com.hazelcast.quorum.impl.ProbabilisticQuorumFunction

All Implemented Interfaces:

HazelcastInstanceAware, MembershipListener, HeartbeatAware, PingAware, QuorumFunction, EventListener

public class ProbabilisticQuorumFunction
extends AbstractPingAwareQuorumFunction
implements HeartbeatAware, QuorumFunction, MembershipListener

Field Summary

Fields inherited from class com.hazelcast.quorum.impl.AbstractPingAwareQuorumFunction

cluster, pingFailureDetector, pingFDEnabled

Constructor Summary

Constructors

Constructor and Description
ProbabilisticQuorumFunction(int quorumSize, long heartbeatIntervalMillis, long acceptableHeartbeatPauseMillis, int maxSampleSize, long minStdDeviationMillis, double suspicionThreshold)

Method Summary

Modifier and Type	Method and Description
boolean	apply(Collection<Member> members) Determines if quorum is present based on the current list of members in the cluster.
boolean	equals(Object o)
long	getAcceptableHeartbeatPauseMillis()
long	getHeartbeatIntervalMillis()
int	getMaxSampleSize()
long	getMinStdDeviationMillis()
double	getSuspicionThreshold()
int	hashCode()
void	memberAdded(MembershipEvent membershipEvent) Invoked when a new member is added to the cluster.
void	memberAttributeChanged(MemberAttributeEvent memberAttributeEvent) Invoked when an attribute of a member was changed.
void	memberRemoved(MembershipEvent membershipEvent) Invoked when an existing member leaves the cluster.
void	onHeartbeat(Member member, long timestamp) Notifies of a received heartbeat.

Methods inherited from class com.hazelcast.quorum.impl.AbstractPingAwareQuorumFunction

isAlivePerIcmp, onPingLost, onPingRestored, setHazelcastInstance

Methods inherited from class java.lang.Object

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

Constructor Detail

ProbabilisticQuorumFunction

public ProbabilisticQuorumFunction(int quorumSize,
                                   long heartbeatIntervalMillis,
                                   long acceptableHeartbeatPauseMillis,
                                   int maxSampleSize,
                                   long minStdDeviationMillis,
                                   double suspicionThreshold)

Method Detail

apply

public boolean apply(Collection<Member> members)

Description copied from interface: QuorumFunction

Determines if quorum is present based on the current list of members in the cluster.
This method should not block nor execute time-consuming operations, otherwise it may stall other quorum function invocations.

Specified by:

apply in interface QuorumFunction

Parameters:

members - snapshot of current member list

Returns:

boolean presence/absence of quorum

memberAdded

public void memberAdded(MembershipEvent membershipEvent)

Description copied from interface: MembershipListener

Invoked when a new member is added to the cluster.

Specified by:

memberAdded in interface MembershipListener

Parameters:

membershipEvent - membership event

memberRemoved

public void memberRemoved(MembershipEvent membershipEvent)

Description copied from interface: MembershipListener

Invoked when an existing member leaves the cluster.

Specified by:

memberRemoved in interface MembershipListener

Parameters:

membershipEvent - membership event when an existing member leaves the cluster

memberAttributeChanged

public void memberAttributeChanged(MemberAttributeEvent memberAttributeEvent)

Description copied from interface: MembershipListener

Invoked when an attribute of a member was changed.

Specified by:

memberAttributeChanged in interface MembershipListener

Parameters:

memberAttributeEvent - member attribute event when an attribute of a member was changed

onHeartbeat

public void onHeartbeat(Member member,
                        long timestamp)

Description copied from interface: HeartbeatAware

Notifies of a received heartbeat. This method is always invoked before QuorumFunction.apply(Collection) so the QuorumFunction can update its internal state before deciding on quorum presence.

Specified by:

onHeartbeat in interface HeartbeatAware

Parameters:

member - member from which heartbeat was received

timestamp - timestmap on which heartbeat was received

getSuspicionThreshold

public double getSuspicionThreshold()

getMaxSampleSize

public int getMaxSampleSize()

getMinStdDeviationMillis

public long getMinStdDeviationMillis()

getAcceptableHeartbeatPauseMillis

public long getAcceptableHeartbeatPauseMillis()

getHeartbeatIntervalMillis

public long getHeartbeatIntervalMillis()

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object