com.hazelcast.internal.cluster

Interface ClusterService

All Superinterfaces:

Cluster, CoreService

All Known Implementing Classes:

ClusterServiceImpl

public interface ClusterService
extends CoreService, Cluster

A service responsible for member related functionality, e.g. members joining, leaving etc.

This API is an internal API; the end user will use the Cluster interface.

Method Summary

Modifier and Type	Method and Description
ClusterClock	getClusterClock() Returns the ClusterClock of the cluster.
String	getClusterId() Returns UUID for the cluster.
Member	getLocalMember() Gets the local member instance.
Address	getMasterAddress() Returns the address of the master member.
MemberImpl	getMember(Address address) Gets the member for the given address.
MemberImpl	getMember(Address address, String uuid) Gets the member with the given UUID and address.
MemberImpl	getMember(String uuid) Gets the member with the given UUID.
Collection<MemberImpl>	getMemberImpls() Gets the collection of members.
int	getMemberListJoinVersion() Returns the member list join version of the local member instance.
int	getMemberListVersion() Returns the current version of member list.
Collection<Member>	getMembers(MemberSelector selector) Returns a collection of the members that satisfy the given MemberSelector.
int	getSize() Gets the current number of members.
int	getSize(MemberSelector selector) Gets the number of members that satisfy the given MemberSelector instance.
Address	getThisAddress() Gets the address of this member.
boolean	isJoined() Returns whether this member joined to a cluster.
boolean	isMaster() Checks if this member is the master.

Methods inherited from interface com.hazelcast.core.Cluster

addMembershipListener, changeClusterState, changeClusterState, changeClusterVersion, changeClusterVersion, getClusterState, getClusterTime, getClusterVersion, getHotRestartService, getMembers, promoteLocalLiteMember, removeMembershipListener, shutdown, shutdown

Method Detail

getMember

MemberImpl getMember(Address address)

Gets the member for the given address.

Parameters:

address - the address of the member to lookup

Returns:

the found member, or null if not found (if the address is null, null is returned)

getMember

MemberImpl getMember(String uuid)

Gets the member with the given UUID.

Parameters:

uuid - the UUID of the member

Returns:

the found member, or null if not found (if the UUID is null, null is returned)

getMember

MemberImpl getMember(Address address,
                     String uuid)

Gets the member with the given UUID and address.

Parameters:

address - the address of the member

uuid - the UUID of the member

Returns:

the found member, or null if not found (if the UUID and/or address is null, null is returned)

getMemberImpls

Collection<MemberImpl> getMemberImpls()

Gets the collection of members.

If we take care of the generics.

Returns:

the collection of member (the returned value will never be null)

getMembers

Collection<Member> getMembers(MemberSelector selector)

Returns a collection of the members that satisfy the given MemberSelector.

Parameters:

selector - MemberSelector instance to filter members to return

Returns:

members that satisfy the given MemberSelector

getMasterAddress

Address getMasterAddress()

Returns the address of the master member.

Returns:

the address of the master member (can be null if the master is not yet known)

isMaster

boolean isMaster()

Checks if this member is the master.

Returns:

true if master, false otherwise

isJoined

boolean isJoined()

Returns whether this member joined to a cluster.

Returns:

true if this member is joined to a cluster, false otherwise

getThisAddress

Address getThisAddress()

Gets the address of this member.

Returns:

the address of this member (the returned value will never be null)

getLocalMember

Member getLocalMember()

Gets the local member instance.

The returned value will never be null, but it may change when local lite member is promoted to a data member via Cluster.promoteLocalLiteMember() or when this member merges to a new cluster after split-brain detected. Returned value should not be cached but instead this method should be called each time when local member is needed.

Specified by:

getLocalMember in interface Cluster

Returns:

the local member instance (the returned value will never be null)

getSize

int getSize()

Gets the current number of members.

Returns:

the current number of members

getSize

int getSize(MemberSelector selector)

Gets the number of members that satisfy the given MemberSelector instance.

Parameters:

selector - MemberSelector instance that filters members to be counted

Returns:

the number of members that satisfy the given MemberSelector instance

getClusterClock

ClusterClock getClusterClock()

Returns the ClusterClock of the cluster.

The returned value will never be null and will never change.

Returns:

the ClusterClock

getClusterId

String getClusterId()

Returns UUID for the cluster.

Returns:

unique UUID for cluster

getMemberListVersion

int getMemberListVersion()

Returns the current version of member list.

Returns:

current version of member list

getMemberListJoinVersion

int getMemberListJoinVersion()

Returns the member list join version of the local member instance.

The join algorithm assigns different member list join versions to each member in the cluster. If two members join at the same time, they will appear on different version of member list.

The uniqueness guarantee of member list join versions is provided except the following scenario: when there is a split-brain issue, if a new node joins to any sub-cluster, it can get a duplicate member list join version, i.e., its member list join version can be assigned to another node in the other sub-cluster(s).

When duplicate member list join version is assigned during network split, the returned value can change to make it unique again. Therefore the caller should call this method repeatedly.

Returns:

the member list join version of the local member instance

Throws:

IllegalStateException - if the local instance is not joined or the cluster just upgraded to 3.10, but local member has not yet learned its join version from the master node.

UnsupportedOperationException - if the cluster version is below 3.10