| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| package org.apache.axis2.clustering.tribes; |
| |
| import org.apache.axis2.clustering.ClusteringConstants; |
| import org.apache.axis2.clustering.LoadBalanceEventHandler; |
| import org.apache.axis2.clustering.control.wka.MemberJoinedCommand; |
| import org.apache.axis2.clustering.control.wka.MemberListCommand; |
| import org.apache.axis2.context.ConfigurationContext; |
| import org.apache.catalina.tribes.Channel; |
| import org.apache.catalina.tribes.Member; |
| import org.apache.catalina.tribes.RemoteProcessException; |
| import org.apache.catalina.tribes.group.Response; |
| import org.apache.catalina.tribes.group.RpcChannel; |
| import org.apache.catalina.tribes.group.interceptors.StaticMembershipInterceptor; |
| import org.apache.catalina.tribes.membership.MemberImpl; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Random; |
| |
| /** |
| * Responsible for managing the membership. Handles membership changes. |
| */ |
| public class MembershipManager { |
| |
| private static final Log log = LogFactory.getLog(MembershipManager.class); |
| |
| private RpcChannel rpcMembershipChannel; |
| private StaticMembershipInterceptor staticMembershipInterceptor; |
| |
| /** |
| * The domain corresponding to the membership handled by this MembershipManager |
| */ |
| private byte[] domain; |
| private LoadBalanceEventHandler loadBalanceEventHandler; |
| private ConfigurationContext configContext; |
| |
| public MembershipManager(ConfigurationContext configContext) { |
| this.configContext = configContext; |
| } |
| |
| public MembershipManager() { |
| } |
| |
| public void setRpcMembershipChannel(RpcChannel rpcMembershipChannel) { |
| this.rpcMembershipChannel = rpcMembershipChannel; |
| } |
| |
| public RpcChannel getRpcMembershipChannel() { |
| return rpcMembershipChannel; |
| } |
| |
| public void setStaticMembershipInterceptor( |
| StaticMembershipInterceptor staticMembershipInterceptor) { |
| this.staticMembershipInterceptor = staticMembershipInterceptor; |
| } |
| |
| public void setLoadBalanceEventHandler(LoadBalanceEventHandler loadBalanceEventHandler) { |
| this.loadBalanceEventHandler = loadBalanceEventHandler; |
| } |
| |
| public void setDomain(byte[] domain) { |
| this.domain = domain; |
| } |
| |
| public byte[] getDomain() { |
| return domain; |
| } |
| |
| /** |
| * List of current members in the cluster. Only the members who are alive will be in this |
| * list |
| */ |
| private final List<Member> members = new ArrayList<Member>(); |
| |
| /** |
| * List of Well-Known members. These members may or may not be alive at a given moment. |
| */ |
| private List<Member> wkaMembers = new ArrayList<Member>(); |
| |
| /** |
| * The member representing this node |
| */ |
| private Member localMember; |
| |
| public Member getLocalMember() { |
| return localMember; |
| } |
| |
| public void setLocalMember(Member localMember) { |
| this.localMember = localMember; |
| } |
| |
| public void addWellKnownMember(Member wkaMember) { |
| wkaMembers.add(wkaMember); |
| } |
| |
| public void removeWellKnownMember(Member wkaMember) { |
| wkaMembers.remove(wkaMember); |
| } |
| |
| /** |
| * A new member is added |
| * |
| * @param member The new member that joined the cluster |
| * @return true If the member was added to the <code>members</code> array; false, otherwise. |
| */ |
| public synchronized boolean memberAdded(Member member) { |
| |
| if(log.isDebugEnabled()){ |
| log.debug("members.contains(member) =" + members.contains(member) ); |
| log.debug("Is in my domain: " + TribesUtil.isInDomain(member, domain)); |
| } |
| |
| // If this member already exists or if the member belongs to another domain, |
| // there is no need to add it |
| if (members.contains(member) || !TribesUtil.isInDomain(member, domain)) { |
| return false; |
| } |
| |
| if (staticMembershipInterceptor != null) { // this interceptor is null when multicast based scheme is used |
| staticMembershipInterceptor.addStaticMember(member); |
| if (log.isDebugEnabled()) { |
| log.debug("Added static member " + TribesUtil.getName(member)); |
| } |
| } |
| |
| boolean shouldAddMember = localMember == null || |
| TribesUtil.areInSameDomain(localMember, member); |
| |
| // If this member is a load balancer, notify the respective load balance event handler? |
| if (loadBalanceEventHandler != null) { |
| log.info("Application member " + TribesUtil.getName(member) + " joined group " + |
| new String(member.getDomain())); |
| loadBalanceEventHandler.applicationMemberAdded(TribesUtil.toAxis2Member(member)); |
| } |
| |
| if (shouldAddMember) { |
| if (rpcMembershipChannel != null && isLocalMemberInitialized() && |
| wkaMembers.contains(member)) { // if it is a well-known member |
| |
| log.info("A WKA member " + TribesUtil.getName(member) + |
| " just joined the group. Sending MEMBER_LIST message."); |
| // send the member list to it |
| MemberListCommand memListCmd; |
| try { |
| memListCmd = new MemberListCommand(); |
| List<Member> members = new ArrayList<Member>(this.members); |
| members.add(localMember); // Need to set the local member too |
| memListCmd.setMembers(members.toArray(new Member[members.size()])); |
| |
| Response[] responses = |
| rpcMembershipChannel.send(new Member[]{member}, memListCmd, |
| RpcChannel.ALL_REPLY, |
| Channel.SEND_OPTIONS_ASYNCHRONOUS | |
| TribesConstants.MEMBERSHIP_MSG_OPTION, 10000); |
| |
| // Once a response is received from the WKA member to the MEMBER_LIST message, |
| // if it does not belong to this domain, simply remove it from the members |
| if(responses != null && responses.length > 0 && responses[0] != null){ |
| Member source = responses[0].getSource(); |
| if(!TribesUtil.areInSameDomain(source, member)){ |
| if(log.isDebugEnabled()){ |
| log.debug("WKA Member " + TribesUtil.getName(source) + |
| " does not belong to local domain " + new String(domain)+ |
| ". Hence removing it from the list."); |
| } |
| members.remove(member); |
| return false; |
| } |
| } |
| } catch (Exception e) { |
| String errMsg = "Could not send MEMBER_LIST to well-known member " + |
| TribesUtil.getName(member); |
| log.error(errMsg, e); |
| throw new RemoteProcessException(errMsg, e); |
| } |
| } |
| members.add(member); |
| if (log.isDebugEnabled()) { |
| log.debug("Added group member " + TribesUtil.getName(member) + " to domain " + |
| new String(member.getDomain())); |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Send the list of members to the <code>member</code> |
| * |
| * @param member The member to whom the member list has to be sent |
| */ |
| public void sendMemberList(Member member) { |
| try { |
| MemberListCommand memListCmd = new MemberListCommand(); |
| List<Member> members = new ArrayList<Member>(this.members); |
| memListCmd.setMembers(members.toArray(new Member[members.size()])); |
| rpcMembershipChannel.send(new Member[]{member}, memListCmd, RpcChannel.ALL_REPLY, |
| Channel.SEND_OPTIONS_ASYNCHRONOUS | |
| TribesConstants.MEMBERSHIP_MSG_OPTION, 10000); |
| if (log.isDebugEnabled()) { |
| log.debug("Sent MEMBER_LIST to " + TribesUtil.getName(member)); |
| } |
| } catch (Exception e) { |
| String errMsg = "Could not send MEMBER_LIST to member " + TribesUtil.getName(member); |
| log.error(errMsg, e); |
| throw new RemoteProcessException(errMsg, e); |
| } |
| } |
| |
| /** |
| * Inform all members that a particular member just joined |
| * |
| * @param member The member who just joined |
| */ |
| public void sendMemberJoinedToAll(Member member) { |
| try { |
| |
| MemberJoinedCommand cmd = new MemberJoinedCommand(); |
| cmd.setMember(member); |
| ArrayList<Member> membersToSend = (ArrayList<Member>) (((ArrayList) members).clone()); |
| membersToSend.remove(member); // Do not send MEMBER_JOINED to the new member who just joined |
| |
| if (membersToSend.size() > 0) { |
| rpcMembershipChannel.send(membersToSend.toArray(new Member[membersToSend.size()]), cmd, |
| RpcChannel.ALL_REPLY, |
| Channel.SEND_OPTIONS_ASYNCHRONOUS | |
| TribesConstants.MEMBERSHIP_MSG_OPTION, |
| 10000); |
| if (log.isDebugEnabled()) { |
| log.debug("Sent MEMBER_JOINED[" + TribesUtil.getName(member) + |
| "] to all members in domain " + new String(domain)); |
| } |
| } |
| } catch (Exception e) { |
| String errMsg = "Could not send MEMBER_JOINED[" + TribesUtil.getName(member) + |
| "] to all members "; |
| log.error(errMsg, e); |
| throw new RemoteProcessException(errMsg, e); |
| } |
| } |
| |
| private boolean isLocalMemberInitialized() { |
| if (configContext == null) { |
| return false; |
| } |
| Object clusterInitialized = |
| configContext.getPropertyNonReplicable(ClusteringConstants.CLUSTER_INITIALIZED); |
| return clusterInitialized != null && clusterInitialized.equals("true"); |
| } |
| |
| /** |
| * A member disappeared |
| * |
| * @param member The member that left the cluster |
| */ |
| public synchronized void memberDisappeared(Member member) { |
| members.remove(member); |
| |
| // Is this an application domain member? |
| if (loadBalanceEventHandler != null) { |
| loadBalanceEventHandler.applicationMemberRemoved(TribesUtil.toAxis2Member(member)); |
| } |
| } |
| |
| /** |
| * Get the list of current members |
| * |
| * @return list of current members |
| */ |
| public synchronized Member[] getMembers() { |
| return members.toArray(new Member[members.size()]); |
| } |
| |
| /** |
| * Get the member that has been alive for the longest time |
| * |
| * @return The member that has been alive for the longest time |
| */ |
| public synchronized Member getLongestLivingMember() { |
| Member longestLivingMember = null; |
| if (members.size() > 0) { |
| Member member0 = members.get(0); |
| long longestAliveTime = member0.getMemberAliveTime(); |
| longestLivingMember = member0; |
| for (Member member : members) { |
| if (longestAliveTime < member.getMemberAliveTime()) { |
| longestAliveTime = member.getMemberAliveTime(); |
| longestLivingMember = member; |
| } |
| } |
| } |
| return longestLivingMember; |
| } |
| |
| /** |
| * Get a random member from the list of current members |
| * |
| * @return A random member from the list of current members |
| */ |
| public synchronized Member getRandomMember() { |
| if (members.size() == 0) { |
| return null; |
| } |
| int memberIndex = new Random().nextInt(members.size()); |
| return members.get(memberIndex); |
| } |
| |
| /** |
| * Check whether there are any members |
| * |
| * @return true if there are other members, false otherwise |
| */ |
| public boolean hasMembers() { |
| return members.size() > 0; |
| } |
| |
| /** |
| * Get a member |
| * |
| * @param member The member to be found |
| * @return The member, if it is found |
| */ |
| public Member getMember(Member member) { |
| if (hasMembers()) { |
| MemberImpl result = null; |
| for (int i = 0; i < this.members.size() && result == null; i++) { |
| if (members.get(i).equals(member)) { |
| result = (MemberImpl) members.get(i); |
| } |
| } |
| return result; |
| } |
| return null; |
| } |
| } |
