org.apache.catalina.tribes.membership
Class Membership

java.lang.Object
  org.apache.catalina.tribes.membership.Membership

All Implemented Interfaces:

Cloneable

public class Membership
extends Object
implements Cloneable

A membership implementation using simple multicast. This is the representation of a multicast membership. This class is responsible for maintaining a list of active cluster nodes in the cluster. If a node fails to send out a heartbeat, the node will be dismissed.

Version:

$Id: Membership.java 1043153 2010-12-07 18:05:31Z markt $

Author:

Filip Hanik, Peter Rossbach

Nested Class Summary

protected static class

Membership.MbrEntry Inner class that represents a member entry

Field Summary

protected static MemberImpl[]	EMPTY_MEMBERS
protected MemberImpl	local The name of this membership, has to be the same as the name for the local member
protected HashMap<MemberImpl,Membership.MbrEntry>	map A map of all the members in the cluster.
protected Comparator<Member>	memberComparator sort members by alive time
protected MemberImpl[]	members A list of all the members in the cluster.

Constructor Summary

Membership(MemberImpl local)

Membership(MemberImpl local, boolean includeLocal)
Constructs a new membership

Membership(MemberImpl local, Comparator<Member> comp)

Membership(MemberImpl local, Comparator<Member> comp, boolean includeLocal)

Method Summary

Membership.MbrEntry	addMember(MemberImpl member) Add a member to this component and sort array with memberComparator
Object	clone()
boolean	contains(Member mbr)
MemberImpl[]	expire(long maxtime) Runs a refresh cycle and returns a list of members that has expired.
MemberImpl	getMember(Member mbr)
protected Membership.MbrEntry[]	getMemberEntries() get a copy from all member entries
MemberImpl[]	getMembers() Returning a list of all the members in the membership We not need a copy: add and remove generate new arrays.
boolean	hasMembers() Returning that service has members or not
boolean	memberAlive(MemberImpl member) Notify the membership that this member has announced itself.
void	removeMember(MemberImpl member) Remove a member from this component.
void	reset() Reset the membership and start over fresh.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_MEMBERS

protected static final MemberImpl[] EMPTY_MEMBERS

local

protected MemberImpl local

The name of this membership, has to be the same as the name for the local member

map

protected HashMap<MemberImpl,Membership.MbrEntry> map

A map of all the members in the cluster.

members

protected MemberImpl[] members

A list of all the members in the cluster.

memberComparator

protected Comparator<Member> memberComparator

sort members by alive time

Constructor Detail

Membership

public Membership(MemberImpl local,
                  boolean includeLocal)

Constructs a new membership

Parameters:

local - - has to be the name of the local member. Used to filter the local member from the cluster membership

includeLocal - - TBA

Membership

public Membership(MemberImpl local)

Membership

public Membership(MemberImpl local,
                  Comparator<Member> comp)

Membership

public Membership(MemberImpl local,
                  Comparator<Member> comp,
                  boolean includeLocal)

Method Detail

clone

public Object clone()

Overrides:

clone in class Object

reset

public void reset()

Reset the membership and start over fresh. Ie, delete all the members and wait for them to ping again and join this membership

memberAlive

public boolean memberAlive(MemberImpl member)

Notify the membership that this member has announced itself.

Parameters:

member - - the member that just pinged us

Returns:

- true if this member is new to the cluster, false otherwise.
- false if this member is the local member or updated.

addMember

public Membership.MbrEntry addMember(MemberImpl member)

Add a member to this component and sort array with memberComparator

Parameters:

member - The member to add

removeMember

public void removeMember(MemberImpl member)

Remove a member from this component.

Parameters:

member - The member to remove

expire

public MemberImpl[] expire(long maxtime)

Runs a refresh cycle and returns a list of members that has expired. This also removes the members from the membership, in such a way that getMembers() = getMembers() - expire()

Parameters:

maxtime - - the max time a member can remain unannounced before it is considered dead.

Returns:

the list of expired members

hasMembers

public boolean hasMembers()

Returning that service has members or not

getMember

public MemberImpl getMember(Member mbr)

contains

public boolean contains(Member mbr)

getMembers

public MemberImpl[] getMembers()

Returning a list of all the members in the membership We not need a copy: add and remove generate new arrays.

getMemberEntries

protected Membership.MbrEntry[] getMemberEntries()

get a copy from all member entries