com.hazelcast.quorum.impl

Class RecentlyActiveQuorumFunction

java.lang.Object

com.hazelcast.quorum.impl.AbstractPingAwareQuorumFunction

com.hazelcast.quorum.impl.RecentlyActiveQuorumFunction

All Implemented Interfaces:

HazelcastInstanceAware, MembershipListener, HeartbeatAware, PingAware, QuorumFunction, EventListener

public class RecentlyActiveQuorumFunction
extends AbstractPingAwareQuorumFunction
implements HeartbeatAware, QuorumFunction, MembershipListener

A quorum function that keeps track of the last heartbeat timestamp per member. For a member to be considered live (for the purpose of determining presence of quorum), a heartbeat must have been received at most heartbeatToleranceMillis milliseconds before current time.

Constructor Summary

Constructors

Constructor and Description
RecentlyActiveQuorumFunction(int quorumSize, int heartbeatToleranceMillis)

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)
int	getHeartbeatToleranceMillis()
int	hashCode()
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, memberAdded, memberAttributeChanged, onPingLost, onPingRestored, setHazelcastInstance

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.hazelcast.core.MembershipListener

memberAdded, memberAttributeChanged

Constructor Detail

RecentlyActiveQuorumFunction

public RecentlyActiveQuorumFunction(int quorumSize,
                                    int heartbeatToleranceMillis)

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. Lite members are excluded and only data members are provided to this method.
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

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

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

Overrides:

memberRemoved in class AbstractPingAwareQuorumFunction

Parameters:

membershipEvent - membership event when an existing member leaves the cluster

getHeartbeatToleranceMillis

public int getHeartbeatToleranceMillis()

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object