/* ***************************************************************************** * $Id: Target.java,v 1.4 2003/05/07 14:40:42 jheiss Exp $ ***************************************************************************** * A Target is a destination for traffic and generally represents a server * providing some sort of service like HTTP or LDAP.  A Distributor will * typically be configured with several Targets (otherwise it wouldn't be * much of a load balancer). ***************************************************************************** * Copyright 2003 Jason Heiss *  * This file is part of Distributor. *  * Distributor is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. *  * Distributor is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. *  * You should have received a copy of the GNU General Public License * along with Distributor; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA ***************************************************************************** */package oss.distributor;import java.net.*;import java.util.List;import java.util.LinkedList;import java.util.Iterator;import java.util.logging.Logger;/* * This class is public to allow 3rd party distribution algorithms and * service tests. */public class Target implements Runnable{	Distributor distributor;	InetAddress addr;  // Address of server	int port;  // Port on server	boolean enabled;  // Is this channel enabled?	boolean terminateOnDisable;	List connections;  // List of Connection's	Logger logger;	DataMover dataMover;	Thread thread;	// Number of consecutive failures to connect to this target	int failureCount;	// How many consecutive connection failures are allowed before this	// target is disabled	int failureCountLimit;	protected Target(Distributor distributor,		InetAddress addr, int port,		int failureCountLimit, boolean terminateOnDisable)	{		this.distributor = distributor;		this.addr = addr;		this.port = port;		this.failureCountLimit = failureCountLimit;		this.terminateOnDisable = terminateOnDisable;		enabled = true;		failureCount = 0;		// Use a linked list to speed up removing dead connections from		// the middle of the list.		connections = new LinkedList();		logger = distributor.getLogger();		dataMover = new DataMover(distributor);		thread = new Thread(this, getClass().getName());		thread.start();	}	public InetAddress getInetAddress()	{		return addr;	}	public int getPort()	{		return port;	}	protected void addConnection(Connection conn)	{		synchronized (connections)		{			connections.add(conn);		}		dataMover.addConnection(conn);	}	public synchronized void enable()	{		enabled = true;		failureCount = 0;	}	public synchronized void disable()	{		if (enabled == true)  // Don't do anything if already disabled		{			enabled = false;			if (terminateOnDisable)			{				terminateAll();			}		}	}	public synchronized boolean isEnabled()	{		return enabled;	}	public synchronized int incrementFailureCount()	{		failureCount++;		if (failureCount > failureCountLimit)		{			disable();		}		return failureCount;	}	public synchronized void resetFailureCount()	{		failureCount = 0;	}	protected void terminateAll()	{		synchronized (connections)		{			Iterator i = connections.iterator();			while (i.hasNext())			{				Connection conn = (Connection) i.next();				logger.fine("Terminating and removing connection " + conn);				conn.terminate();				i.remove();			}		}	}	/*	 * Remove connections which have terminated.	 * Frees up memory and keeps our connection count accurate.	 */	public void run()	{		while (true)		{			synchronized (connections)			{				Iterator i = connections.iterator();				while (i.hasNext())				{					Connection conn = (Connection) i.next();					if (conn.isTerminated())					{						logger.finer("Removing terminiated connection");						i.remove();					}				}			}			try			{				Thread.sleep(5000);			} catch (InterruptedException e) {}		}	}	public int numberOfConnections()	{		synchronized (connections)		{			return connections.size();		}	}	public String toString()	{		String string = "Target: " + addr + ":" + port;					if (enabled)		{			string += " with " + numberOfConnections() + " connections";		}		else		{			string += " DISABLED";		}		return string;	}}