org.jgroups.protocols.pbcast

Class GMS.DefaultMembershipPolicy

java.lang.Object

org.jgroups.protocols.pbcast.GMS.DefaultMembershipPolicy

All Implemented Interfaces:

MembershipChangePolicy

Direct Known Subclasses:

LargestWinningPolicy

Enclosing class:

GMS

public static class GMS.DefaultMembershipPolicy
extends Object
implements MembershipChangePolicy

Constructor Summary

Constructors

Constructor and Description
DefaultMembershipPolicy()

Method Summary

Modifier and Type	Method and Description
List<Address>	getNewMembership(Collection<Address> current_members, Collection<Address> joiners, Collection<Address> leavers, Collection<Address> suspects) Takes the existing membership list and removes suspected and left members, then adds new members to the end of the list
List<Address>	getNewMembership(Collection<Collection<Address>> subviews) Default implementation for a merge.
static List<Address>	getNewMembershipOld(Collection<Collection<Address>> subviews) Old default implementation for a merge.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultMembershipPolicy

public DefaultMembershipPolicy()

Method Detail

getNewMembership

public List<Address> getNewMembership(Collection<Address> current_members,
                                      Collection<Address> joiners,
                                      Collection<Address> leavers,
                                      Collection<Address> suspects)

Takes the existing membership list and removes suspected and left members, then adds new members to the end of the list

Specified by:

getNewMembership in interface MembershipChangePolicy

Parameters:

current_members - The list of current members. Guaranteed to be non-null (but may be empty)

joiners - The joining members. Guaranteed to be non-null (but may be empty)

leavers - Members that are leaving. Guaranteed to be non-null (but may be empty)

suspects - Members which are suspected. Guaranteed to be non-null (but may be empty)

Returns:

The new membership. Needs to be non-null and cannot contain duplicates

getNewMembershipOld

public static List<Address> getNewMembershipOld(Collection<Collection<Address>> subviews)

Old default implementation for a merge. Adds all members into a list, sorts the list and returns it

Parameters:

subviews - A list of membership lists, e.g. [{A,B,C}, {M,N,O,P}, {X,Y,Z}]. This is a merge between 3 subviews. Guaranteed to be non-null (but may be empty)

Returns:

The new membership. Needs to be non-null and cannot contain duplicates

getNewMembership

public List<Address> getNewMembership(Collection<Collection<Address>> subviews)

Default implementation for a merge. Picks the new coordinator among the coordinators of the old subviews by getting all coords, sorting them and picking the first. Then the coord is added to the new list, and all subviews are subsequently added.

Tries to minimize coordinatorship moving around between different members

Specified by:

getNewMembership in interface MembershipChangePolicy

Parameters:

subviews - A list of membership lists, e.g. [{A,B,C}, {M,N,O,P}, {X,Y,Z}]. This is a merge between 3 subviews. Guaranteed to be non-null (but may be empty)

Returns:

The new membership. Needs to be non-null and cannot contain duplicates