/*
 * 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.catalina.ha.tcp;

import java.beans.PropertyChangeSupport;
import java.io.IOException;
import java.io.Serializable;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.catalina.Container;
import org.apache.catalina.Context;
import org.apache.catalina.Engine;
import org.apache.catalina.Host;
import org.apache.catalina.Lifecycle;
import org.apache.catalina.LifecycleEvent;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.LifecycleListener;
import org.apache.catalina.Manager;
import org.apache.catalina.Valve;
import org.apache.catalina.ha.CatalinaCluster;
import org.apache.catalina.tribes.Channel;
import org.apache.catalina.tribes.ChannelListener;
import org.apache.catalina.ha.ClusterListener;
import org.apache.catalina.ha.ClusterManager;
import org.apache.catalina.ha.ClusterMessage;
import org.apache.catalina.ha.ClusterValve;
import org.apache.catalina.tribes.Member;
import org.apache.catalina.tribes.MembershipListener;
import org.apache.catalina.tribes.group.GroupChannel;

import org.apache.catalina.ha.session.DeltaManager;
import org.apache.catalina.ha.util.IDynamicProperty;
import org.apache.catalina.util.LifecycleSupport;
import org.apache.catalina.util.StringManager;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.tomcat.util.IntrospectionUtils;

/**
 * A <b>Cluster </b> implementation using simple multicast. Responsible for
 * setting up a cluster and provides callers with a valid multicast
 * receiver/sender.
 * 
 * FIXME remove install/remove/start/stop context dummys
 * FIXME wrote testcases 
 * 
 * @author Filip Hanik
 * @author Remy Maucherat
 * @author Peter Rossbach
 * @version $Revision$, $Date$
 */
public class SimpleTcpCluster 
    implements CatalinaCluster, Lifecycle, LifecycleListener, IDynamicProperty,
               MembershipListener, ChannelListener{

    public static Log log = LogFactory.getLog(SimpleTcpCluster.class);

    // ----------------------------------------------------- Instance Variables

    /**
     * Descriptive information about this component implementation.
     */
    protected static final String info = "SimpleTcpCluster/2.2";

    public static final String BEFORE_MEMBERREGISTER_EVENT = "before_member_register";

    public static final String AFTER_MEMBERREGISTER_EVENT = "after_member_register";

    public static final String BEFORE_MANAGERREGISTER_EVENT = "before_manager_register";

    public static final String AFTER_MANAGERREGISTER_EVENT = "after_manager_register";

    public static final String BEFORE_MANAGERUNREGISTER_EVENT = "before_manager_unregister";

    public static final String AFTER_MANAGERUNREGISTER_EVENT = "after_manager_unregister";

    public static final String BEFORE_MEMBERUNREGISTER_EVENT = "before_member_unregister";

    public static final String AFTER_MEMBERUNREGISTER_EVENT = "after_member_unregister";

    public static final String SEND_MESSAGE_FAILURE_EVENT = "send_message_failure";

    public static final String RECEIVE_MESSAGE_FAILURE_EVENT = "receive_message_failure";
    
    /**
     * Group channel.
     */
    protected Channel channel = new GroupChannel();


    /**
     * Name for logging purpose
     */
    protected String clusterImpName = "SimpleTcpCluster";

    /**
     * The string manager for this package.
     */
    protected StringManager sm = StringManager.getManager(Constants.Package);

    /**
     * The cluster name to join
     */
    protected String clusterName ;

    /**
     * The Container associated with this Cluster.
     */
    protected Container container = null;

    /**
     * The lifecycle event support for this component.
     */
    protected LifecycleSupport lifecycle = new LifecycleSupport(this);

    /**
     * Has this component been started?
     */
    protected boolean started = false;

    /**
     * The property change support for this component.
     */
    protected PropertyChangeSupport support = new PropertyChangeSupport(this);

    /**
     * The context name <->manager association for distributed contexts.
     */
    protected Map managers = new HashMap();

    private String managerClassName = "org.apache.catalina.ha.session.DeltaManager";


    private List valves = new ArrayList();

    private org.apache.catalina.ha.ClusterDeployer clusterDeployer;

    /**
     * Listeners of messages
     */
    protected List clusterListeners = new ArrayList();

    /**
     * Comment for <code>notifyLifecycleListenerOnFailure</code>
     */
    private boolean notifyLifecycleListenerOnFailure = false;

    /**
     * dynamic sender <code>properties</code>
     */
    private Map properties = new HashMap();
    
    private int channelSendOptions = 
        Channel.SEND_OPTIONS_ASYNCHRONOUS |
        Channel.SEND_OPTIONS_SYNCHRONIZED_ACK |
        Channel.SEND_OPTIONS_USE_ACK;

    // ------------------------------------------------------------- Properties

    public SimpleTcpCluster() {
    }

    /**
     * Return descriptive information about this Cluster implementation and the
     * corresponding version number, in the format
     * <code>&lt;description&gt;/&lt;version&gt;</code>.
     */
    public String getInfo() {
        return (info);
    }

    /**
     * Set the name of the cluster to join, if no cluster with this name is
     * present create one.
     * 
     * @param clusterName
     *            The clustername to join
     */
    public void setClusterName(String clusterName) {
        this.clusterName = clusterName;
    }

    /**
     * Return the name of the cluster that this Server is currently configured
     * to operate within.
     * 
     * @return The name of the cluster associated with this server
     */
    public String getClusterName() {
        if(clusterName == null && container != null)
            return container.getName() ;
        return clusterName;
    }

    /**
     * Set the Container associated with our Cluster
     * 
     * @param container
     *            The Container to use
     */
    public void setContainer(Container container) {
        Container oldContainer = this.container;
        this.container = container;
        support.firePropertyChange("container", oldContainer, this.container);
    }

    /**
     * Get the Container associated with our Cluster
     * 
     * @return The Container associated with our Cluster
     */
    public Container getContainer() {
        return (this.container);
    }

    /**
     * @return Returns the notifyLifecycleListenerOnFailure.
     */
    public boolean isNotifyLifecycleListenerOnFailure() {
        return notifyLifecycleListenerOnFailure;
    }

    /**
     * @param notifyListenerOnFailure
     *            The notifyLifecycleListenerOnFailure to set.
     */
    public void setNotifyLifecycleListenerOnFailure(
            boolean notifyListenerOnFailure) {
        boolean oldNotifyListenerOnFailure = this.notifyLifecycleListenerOnFailure;
        this.notifyLifecycleListenerOnFailure = notifyListenerOnFailure;
        support.firePropertyChange("notifyLifecycleListenerOnFailure",
                oldNotifyListenerOnFailure,
                this.notifyLifecycleListenerOnFailure);
    }

    public String getManagerClassName() {
        if(managerClassName != null)
            return managerClassName;
        return (String)getProperty("manager.className");
    }

    public void setManagerClassName(String managerClassName) {
        this.managerClassName = managerClassName;
    }

    /**
     * Add cluster valve 
     * Cluster Valves are only add to container when cluster is started!
     * @param valve The new cluster Valve.
     */
    public void addValve(Valve valve) {
        if (valve instanceof ClusterValve)
            valves.add(valve);
    }

    /**
     * get all cluster valves
     * @return current cluster valves
     */
    public Valve[] getValves() {
        return (Valve[]) valves.toArray(new Valve[valves.size()]);
    }

    /**
     * Get the cluster listeners associated with this cluster. If this Array has
     * no listeners registered, a zero-length array is returned.
     */
    public ClusterListener[] findClusterListeners() {
        if (clusterListeners.size() > 0) {
            ClusterListener[] listener = new ClusterListener[clusterListeners.size()];
            clusterListeners.toArray(listener);
            return listener;
        } else
            return new ClusterListener[0];

    }

    /**
     * add cluster message listener and register cluster to this listener
     * 
     * @see org.apache.catalina.ha.CatalinaCluster#addClusterListener(org.apache.catalina.ha.MessageListener)
     */
    public void addClusterListener(ClusterListener listener) {
        if (listener != null && !clusterListeners.contains(listener)) {
            clusterListeners.add(listener);
            listener.setCluster(this);
        }
    }

    /**
     * remove message listener and deregister Cluster from listener
     * 
     * @see org.apache.catalina.ha.CatalinaCluster#removeClusterListener(org.apache.catalina.ha.MessageListener)
     */
    public void removeClusterListener(ClusterListener listener) {
        if (listener != null) {
            clusterListeners.remove(listener);
            listener.setCluster(null);
        }
    }

    /**
     * get current Deployer
     */
    public org.apache.catalina.ha.ClusterDeployer getClusterDeployer() {
        return clusterDeployer;
    }

    /**
     * set a new Deployer, must be set before cluster started!
     */
    public void setClusterDeployer(
            org.apache.catalina.ha.ClusterDeployer clusterDeployer) {
        this.clusterDeployer = clusterDeployer;
    }

    public void setChannel(Channel channel) {
        this.channel = channel;
    }

    /**
     * has members
     */
    protected boolean hasMembers = false;
    public boolean hasMembers() {
        return hasMembers;
    }
    
    /**
     * Get all current cluster members
     * @return all members or empty array 
     */
    public Member[] getMembers() {
        return channel.getMembers();
    }

    /**
     * Return the member that represents this node.
     * 
     * @return Member
     */
    public Member getLocalMember() {
        return channel.getLocalMember(true);
    }

    // ------------------------------------------------------------- dynamic
    // manager property handling

    /**
     * JMX hack to direct use at jconsole
     * 
     * @param name
     * @param value
     */
    public void setProperty(String name, String value) {
        setProperty(name, (Object) value);
    }

    /**
     * set config attributes with reflect and propagate to all managers
     * 
     * @param name
     * @param value
     */
    public void setProperty(String name, Object value) {
        if (log.isTraceEnabled())
            log.trace(sm.getString("SimpleTcpCluster.setProperty", name, value,
                    properties.get(name)));

        properties.put(name, value);
        if(started) {
            // FIXME Hmm, is that correct when some DeltaManagers are direct configured inside Context?
            // Why we not support it for other elements, like sender, receiver or membership?
            // Must we restart element after change?
            if (name.startsWith("manager")) {
                String key = name.substring("manager".length() + 1);
                String pvalue = value.toString();
                for (Iterator iter = managers.values().iterator(); iter.hasNext();) {
                    Manager manager = (Manager) iter.next();
                    if(manager instanceof DeltaManager && ((ClusterManager) manager).isDefaultMode()) {
                        IntrospectionUtils.setProperty(manager, key, pvalue );
                    }
                }
            } 
        }
    }

    /**
     * get current config
     * 
     * @param key
     * @return The property
     */
    public Object getProperty(String key) {
        if (log.isTraceEnabled())
            log.trace(sm.getString("SimpleTcpCluster.getProperty", key));
        return properties.get(key);
    }

    /**
     * Get all properties keys
     * 
     * @return An iterator over the property names.
     */
    public Iterator getPropertyNames() {
        return properties.keySet().iterator();
    }

    /**
     * remove a configured property.
     * 
     * @param key
     */
    public void removeProperty(String key) {
        properties.remove(key);
    }

    /**
     * transfer properties from cluster configuration to subelement bean.
     * @param prefix
     * @param bean
     */
    protected void transferProperty(String prefix, Object bean) {
        if (prefix != null) {
            for (Iterator iter = getPropertyNames(); iter.hasNext();) {
                String pkey = (String) iter.next();
                if (pkey.startsWith(prefix)) {
                    String key = pkey.substring(prefix.length() + 1);
                    Object value = getProperty(pkey);
                    IntrospectionUtils.setProperty(bean, key, value.toString());
                }
            }
        }
    }

    // --------------------------------------------------------- Public Methods

    /**
     * @return Returns the managers.
     */
    public Map getManagers() {
        return managers;
    }

    public Channel getChannel() {
        return channel;
    }

    /**
     * Create new Manager without add to cluster (comes with start the manager)
     * 
     * @param name
     *            Context Name of this manager
     * @see org.apache.catalina.Cluster#createManager(java.lang.String)
     * @see #addManager(String, Manager)
     * @see DeltaManager#start()
     */
    public synchronized Manager createManager(String name) {
        if (log.isDebugEnabled()) log.debug("Creating ClusterManager for context " + name + " using class " + getManagerClassName());
        Manager manager = null;
        ClassLoader oldCtxLoader = Thread.currentThread().getContextClassLoader();
        try {
            Thread.currentThread().setContextClassLoader(SimpleTcpCluster.class.getClassLoader());
            manager = (Manager) getClass().getClassLoader().loadClass(getManagerClassName()).newInstance();
        } catch (Exception x) {
            log.error("Unable to load class for replication manager", x);
            manager = new org.apache.catalina.ha.session.DeltaManager();
        } finally {
            Thread.currentThread().setContextClassLoader(oldCtxLoader);
            if(manager != null) {
                manager.setDistributable(true);
                if (manager instanceof ClusterManager) {
                    ClusterManager cmanager = (ClusterManager) manager ;
                    cmanager.setDefaultMode(true);
                    cmanager.setName(getManagerName(name,manager));
                    cmanager.setCluster(this);
                }
            }
        }
        return manager;
    }

    /**
     * remove an application form cluster replication bus
     * 
     * @see org.apache.catalina.ha.CatalinaCluster#removeManager(java.lang.String,Manager)
     */
    public void removeManager(String name,Manager manager) {
        if (manager != null) {
            // Notify our interested LifecycleListeners
            lifecycle.fireLifecycleEvent(BEFORE_MANAGERUNREGISTER_EVENT,manager);
            managers.remove(getManagerName(name,manager));
            if (manager instanceof ClusterManager) ((ClusterManager) manager).setCluster(null);
            // Notify our interested LifecycleListeners
            lifecycle.fireLifecycleEvent(AFTER_MANAGERUNREGISTER_EVENT, manager);
        }
    }

    /**
     * add an application to cluster replication bus
     * 
     * @param name
     *            of the context
     * @param manager
     *            manager to register
     * @see org.apache.catalina.ha.CatalinaCluster#addManager(java.lang.String,
     *      org.apache.catalina.Manager)
     */
    public void addManager(String name, Manager manager) {
        if (!manager.getDistributable()) {
            log.warn("Manager with name " + name + " is not distributable, can't add as cluster manager");
            return;
        }
        // Notify our interested LifecycleListeners
        lifecycle.fireLifecycleEvent(BEFORE_MANAGERREGISTER_EVENT, manager);
        String clusterName = getManagerName(name, manager);
        if (manager instanceof ClusterManager) {
            ClusterManager cmanager = (ClusterManager) manager ;
            cmanager.setName(clusterName);
            cmanager.setCluster(this);
            if(cmanager.isDefaultMode()) transferProperty("manager",cmanager);
        }
        managers.put(clusterName, manager);
        // Notify our interested LifecycleListeners
        lifecycle.fireLifecycleEvent(AFTER_MANAGERREGISTER_EVENT, manager);
    }

    /**
     * Returns the name for the cluster manager.  This name
     * depends on whether the cluster manager is defined inside
     * a Host or an Engine.
     * Should the cluster be defined in the Engine element, the manager name
     * is Host.getName+"#"+Context.getManager().getName()
     * otherwise the name is simply Context.getManager().getName()
     * @param name The current name
     * @param manager The cluster manager implementation
     * @return The name to use for the cluster manager
     */
    public String getManagerName(String name, Manager manager) {
        String clusterName = name ;
        if ( clusterName == null ) clusterName = manager.getContainer().getName();
        if(getContainer() instanceof Engine) {
            Container context = manager.getContainer() ;
            if(context != null && context instanceof Context) {
                Container host = ((Context)context).getParent();
                if(host != null && host instanceof Host && clusterName!=null && !(clusterName.indexOf("#")>=0))
                    clusterName = host.getName() +"#" + clusterName ;
            }
        }
        return clusterName;
    }

    /*
     * Get Manager
     * 
     * @see org.apache.catalina.ha.CatalinaCluster#getManager(java.lang.String)
     */
    public Manager getManager(String name) {
        return (Manager) managers.get(name);
    }
    
    // ------------------------------------------------------ Lifecycle Methods

    /**
     * Execute a periodic task, such as reloading, etc. This method will be
     * invoked inside the classloading context of this container. Unexpected
     * throwables will be caught and logged.
     * @see org.apache.catalina.ha.deploy.FarmWarDeployer#backgroundProcess()
     * @see ReplicationTransmitter#backgroundProcess()
     */
    public void backgroundProcess() {
        if (clusterDeployer != null) clusterDeployer.backgroundProcess();
        //send a heartbeat through the channel
        if ( channel !=null ) channel.heartbeat();
    }

    /**
     * Add a lifecycle event listener to this component.
     * 
     * @param listener
     *            The listener to add
     */
    public void addLifecycleListener(LifecycleListener listener) {
        lifecycle.addLifecycleListener(listener);
    }

    /**
     * Get the lifecycle listeners associated with this lifecycle. If this
     * Lifecycle has no listeners registered, a zero-length array is returned.
     */
    public LifecycleListener[] findLifecycleListeners() {

        return lifecycle.findLifecycleListeners();

    }

    /**
     * Remove a lifecycle event listener from this component.
     * 
     * @param listener
     *            The listener to remove
     */
    public void removeLifecycleListener(LifecycleListener listener) {
        lifecycle.removeLifecycleListener(listener);
    }

    /**
     * Use as base to handle start/stop/periodic Events from host. Currently
     * only log the messages as trace level.
     * 
     * @see org.apache.catalina.LifecycleListener#lifecycleEvent(org.apache.catalina.LifecycleEvent)
     */
    public void lifecycleEvent(LifecycleEvent lifecycleEvent) {
        if (log.isTraceEnabled())
            log.trace(sm.getString("SimpleTcpCluster.event.log", lifecycleEvent.getType(), lifecycleEvent.getData()));
    }

    // ------------------------------------------------------ public

    /**
     * Prepare for the beginning of active use of the public methods of this
     * component. This method should be called after <code>configure()</code>,
     * and before any of the public methods of the component are utilized. <BR>
     * Starts the cluster communication channel, this will connect with the
     * other nodes in the cluster, and request the current session state to be
     * transferred to this node.
     * 
     * @exception IllegalStateException
     *                if this component has already been started
     * @exception LifecycleException
     *                if this component detects a fatal error that prevents this
     *                component from being used
     */
    public void start() throws LifecycleException {
        if (started)
            throw new LifecycleException(sm.getString("cluster.alreadyStarted"));
        if (log.isInfoEnabled()) log.info("Cluster is about to start");

        // Notify our interested LifecycleListeners
        lifecycle.fireLifecycleEvent(BEFORE_START_EVENT, this);
        try {
            if ( clusterDeployer != null ) clusterDeployer.setCluster(this);
            this.registerClusterValve();
            if ( channel == null ) channel = new GroupChannel();
            channel.addMembershipListener(this);
            channel.addChannelListener(this);
            channel.start(channel.DEFAULT);
            if (clusterDeployer != null) clusterDeployer.start();
            this.started = true;
            // Notify our interested LifecycleListeners
            lifecycle.fireLifecycleEvent(AFTER_START_EVENT, this);
        } catch (Exception x) {
            log.error("Unable to start cluster.", x);
            throw new LifecycleException(x);
        }
    }

    /**
     * register all cluster valve to host or engine
     * @throws Exception
     * @throws ClassNotFoundException
     */
    protected void registerClusterValve() throws Exception {
        if(container != null ) {
            for (Iterator iter = valves.iterator(); iter.hasNext();) {
                ClusterValve valve = (ClusterValve) iter.next();
                if (log.isDebugEnabled())
                    log.debug("Invoking addValve on " + getContainer()
                            + " with class=" + valve.getClass().getName());
                if (valve != null) {
                    IntrospectionUtils.callMethodN(getContainer(), "addValve",
                            new Object[] { valve },
                            new Class[] { org.apache.catalina.Valve.class });

                }
                valve.setCluster(this);
            }
        }
    }

    /**
     * unregister all cluster valve to host or engine
     * @throws Exception
     * @throws ClassNotFoundException
     */
    protected void unregisterClusterValve() throws Exception {
        for (Iterator iter = valves.iterator(); iter.hasNext();) {
            ClusterValve valve = (ClusterValve) iter.next();
            if (log.isDebugEnabled())
                log.debug("Invoking removeValve on " + getContainer()
                        + " with class=" + valve.getClass().getName());
            if (valve != null) {
                    IntrospectionUtils.callMethodN(getContainer(), "removeValve",
                        new Object[] { valve }, new Class[] { org.apache.catalina.Valve.class });
            }
            valve.setCluster(this);
        }
    }

    /**
     * Gracefully terminate the active cluster component.<br/>
     * This will disconnect the cluster communication channel, stop the
     * listener and deregister the valves from host or engine.<br/><br/>
     * <b>Note:</b><br/>The sub elements receiver, sender, membership,
     * listener or valves are not removed. You can easily start the cluster again.
     * 
     * @exception IllegalStateException
     *                if this component has not been started
     * @exception LifecycleException
     *                if this component detects a fatal error that needs to be
     *                reported
     */
    public void stop() throws LifecycleException {

        if (!started)
            throw new IllegalStateException(sm.getString("cluster.notStarted"));
        // Notify our interested LifecycleListeners
        lifecycle.fireLifecycleEvent(BEFORE_STOP_EVENT, this);

        if (clusterDeployer != null) clusterDeployer.stop();
        this.managers.clear();
        try {
            if ( clusterDeployer != null ) clusterDeployer.setCluster(null);
            channel.stop(Channel.DEFAULT);
            channel.removeChannelListener(this);
            channel.removeMembershipListener(this);
            this.unregisterClusterValve();
        } catch (Exception x) {
            log.error("Unable to stop cluster valve.", x);
        }
        started = false;
        // Notify our interested LifecycleListeners
        lifecycle.fireLifecycleEvent(AFTER_STOP_EVENT, this);
   }

    
    /**
     * send message to all cluster members
     * @param msg message to transfer
     * 
     * @see org.apache.catalina.ha.CatalinaCluster#send(org.apache.catalina.ha.ClusterMessage)
     */
    public void send(ClusterMessage msg) {
        send(msg, null);
    }

    /**
     * send message to all cluster members same cluster domain
     * 
     * @see org.apache.catalina.ha.CatalinaCluster#send(org.apache.catalina.ha.ClusterMessage)
     */
    public void sendClusterDomain(ClusterMessage msg) {
        send(msg,null);
    } 

    
    /**
     * send a cluster message to one member
     * 
     * @param msg message to transfer
     * @param dest Receiver member
     * @see org.apache.catalina.ha.CatalinaCluster#send(org.apache.catalina.ha.ClusterMessage,
     *      org.apache.catalina.ha.Member)
     */
    public void send(ClusterMessage msg, Member dest) {
        try {
            msg.setAddress(getLocalMember());
            if (dest != null) {
                if (!getLocalMember().equals(dest)) {
                    channel.send(new Member[] {dest}, msg,channelSendOptions);
                } else
                    log.error("Unable to send message to local member " + msg);
            } else {
                channel.send(channel.getMembers(),msg,channelSendOptions);
            }
        } catch (Exception x) {
            log.error("Unable to send message through cluster sender.", x);
        }
    }

    /**
     * New cluster member is registered
     * 
     * @see org.apache.catalina.ha.MembershipListener#memberAdded(org.apache.catalina.ha.Member)
     */
    public void memberAdded(Member member) {
        try {
            hasMembers = channel.hasMembers();
            if (log.isInfoEnabled()) log.info("Replication member added:" + member);
            // Notify our interested LifecycleListeners
            lifecycle.fireLifecycleEvent(BEFORE_MEMBERREGISTER_EVENT, member);
            // Notify our interested LifecycleListeners
            lifecycle.fireLifecycleEvent(AFTER_MEMBERREGISTER_EVENT, member);
        } catch (Exception x) {
            log.error("Unable to connect to replication system.", x);
        }

    }

    /**
     * Cluster member is gone
     * 
     * @see org.apache.catalina.ha.MembershipListener#memberDisappeared(org.apache.catalina.ha.Member)
     */
    public void memberDisappeared(Member member) {
        try {
            hasMembers = channel.hasMembers();            
            if (log.isInfoEnabled()) log.info("Received member disappeared:" + member);
            // Notify our interested LifecycleListeners
            lifecycle.fireLifecycleEvent(BEFORE_MEMBERUNREGISTER_EVENT, member);
            // Notify our interested LifecycleListeners
            lifecycle.fireLifecycleEvent(AFTER_MEMBERUNREGISTER_EVENT, member);
        } catch (Exception x) {
            log.error("Unable remove cluster node from replication system.", x);
        }
    }

    // --------------------------------------------------------- receiver
    // messages

    /**
     * notify all listeners from receiving a new message is not ClusterMessage
     * emitt Failure Event to LifecylceListener
     * 
     * @param message
     *            receveived Message
     */
    public boolean accept(Serializable msg, Member sender) {
        return (msg instanceof ClusterMessage);
    }
    
    
    public void messageReceived(Serializable message, Member sender) {
        ClusterMessage fwd = (ClusterMessage)message;
        fwd.setAddress(sender);
        messageReceived(fwd);
    }

    public void messageReceived(ClusterMessage message) {

        long start = 0;
        if (log.isDebugEnabled() && message != null)
            log.debug("Assuming clocks are synched: Replication for "
                    + message.getUniqueId() + " took="
                    + (System.currentTimeMillis() - (message).getTimestamp())
                    + " ms.");

        //invoke all the listeners
        boolean accepted = false;
        if (message != null) {
            for (Iterator iter = clusterListeners.iterator(); iter.hasNext();) {
                ClusterListener listener = (ClusterListener) iter.next();
                if (listener.accept(message)) {
                    accepted = true;
                    listener.messageReceived(message);
                }
            }
        }
        if (!accepted && log.isDebugEnabled()) {
            if (notifyLifecycleListenerOnFailure) {
                Member dest = message.getAddress();
                // Notify our interested LifecycleListeners
                lifecycle.fireLifecycleEvent(RECEIVE_MESSAGE_FAILURE_EVENT,
                        new SendMessageData(message, dest, null));
            }
            log.debug("Message " + message.toString() + " from type "
                    + message.getClass().getName()
                    + " transfered but no listener registered");
        }
        return;
    }

    // --------------------------------------------------------- Logger

    public Log getLogger() {
        return log;
    }


    // ------------------------------------------------------------- deprecated

    /**
     * 
     * @see org.apache.catalina.Cluster#setProtocol(java.lang.String)
     */
    public void setProtocol(String protocol) {
    }

    /**
     * @see org.apache.catalina.Cluster#getProtocol()
     */
    public String getProtocol() {
        return null;
    }

    /**
     * @see org.apache.catalina.Cluster#startContext(java.lang.String)
     */
    public void startContext(String contextPath) throws IOException {
        
    }

    /**
     * @see org.apache.catalina.Cluster#installContext(java.lang.String, java.net.URL)
     */
    public void installContext(String contextPath, URL war) {
        
    }

    /**
     * @see org.apache.catalina.Cluster#stop(java.lang.String)
     */
    public void stop(String contextPath) throws IOException {
        
    }
}