/*
* JBoss, Home of Professional Open Source.
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.ha.framework.interfaces;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Method;
import java.rmi.ConnectException;
import java.rmi.ConnectIOException;
import java.rmi.NoSuchObjectException;
import java.rmi.RemoteException;
import java.rmi.UnknownHostException;
import java.util.ArrayList;
import java.util.List;
import org.jboss.ha.client.loadbalance.LoadBalancePolicy;
import org.jboss.invocation.MarshalledInvocation;
import org.jboss.logging.Logger;
/**
*
*
* @author <a href="mailto:sacha.labourey@cogito-info.ch">Sacha Labourey</a>
* @author <a href="mailto:bill@burkecentral.com">Bill Burke</a>
* @version $Revision: 104443 $
*/
public class HARMIClient
implements HARMIProxy, java.lang.reflect.InvocationHandler, java.io.Serializable
{
// Constants -----------------------------------------------------
/** The serialVersionUID
* @since
*/
private static final long serialVersionUID = -1227816478666532463L;
private static final Logger log = Logger.getLogger(HARMIClient.class);
/** {@link Object#toString} method reference. */
protected static final Method TO_STRING;
/** {@link Object#hashCode} method reference. */
protected static final Method HASH_CODE;
/** {@link Object#equals} method reference. */
protected static final Method EQUALS;
static
{
try
{
final Class<?>[] empty = {};
final Class<?> type = Object.class;
TO_STRING = type.getMethod("toString", empty);
HASH_CODE = type.getMethod("hashCode", empty);
EQUALS = type.getMethod("equals", new Class[] { type });
}
catch (Exception e)
{
e.printStackTrace();
throw new ExceptionInInitializerError(e);
}
}
// Attributes ----------------------------------------------------
protected String key = null;
//protected ArrayList targets = null;
protected LoadBalancePolicy loadBalancePolicy;
//protected transient long currentViewId = 0;
protected transient Object local = null;
protected transient boolean trace;
FamilyClusterInfo familyClusterInfo = null;
// Static --------------------------------------------------------
// Constructors --------------------------------------------------
public HARMIClient() {}
public HARMIClient(List<?> targets, LoadBalancePolicy policy, String key)
{
this(targets, 0, policy, key, null);
}
public HARMIClient(List<?> targets,
long initViewId,
LoadBalancePolicy policy,
String key,
Object local)
{
this.familyClusterInfo = ClusteringTargetsRepository.initTarget (key, targets, initViewId);
//this.targets = targets;
this.loadBalancePolicy = policy;
if (this.loadBalancePolicy instanceof org.jboss.ha.framework.interfaces.LoadBalancePolicy)
{
((org.jboss.ha.framework.interfaces.LoadBalancePolicy)this.loadBalancePolicy).init(this);
}
this.key = key;
this.local = local;
this.trace = log.isTraceEnabled();
if( trace )
log.trace("Init, cluterInfo: "+familyClusterInfo+", policy="+loadBalancePolicy);
}
// Public --------------------------------------------------------
/*
public ArrayList getTargets()
{
return targets;
}
public void setTargets(ArrayList newTargets)
{
synchronized(targets)
{
targets.clear();
targets.addAll(newTargets);
}
}
*/
public void updateClusterInfo (List<?> targets, long viewId)
{
if (familyClusterInfo != null)
this.familyClusterInfo.updateClusterInfo (targets, viewId);
}
public Object getRemoteTarget()
{
// System.out.println("number of targets: " + targets.size());
return loadBalancePolicy.chooseTarget(this.familyClusterInfo); // legacy, no Invocation object in raw HA-RMI
}
public void remoteTargetHasFailed(Object target)
{
removeDeadTarget(target);
}
public Method findLocalMethod(Method method, Object[] args) throws Exception
{
return method;
}
/**
* Invoke the given method against a remote server. If the call results
* in certain {@link RemoteException} subtypes, catch the exception and
* attempt to fail over to another server.
* <p>
* Failover will only be attempted if the remote call throws an exception
* whose type indicates the call never reached the server:
* <ul>
* <li>{@link java.rmi.ConnectException}</li>
* <li>{@link java.rmi.ConnectIOException}</li>
* <li>{@link java.rmi.NoSuchObjectException}</li>
* <li>{@link java.rmi.UnknownHostException}</li>
* </ul>
* </p>
* <p>
* All other exception types will not be caught.
* </p>
* <p>
* If one of the above exception types is caught when invoking against the
* last known server, then a {@link RemoteException} will be thrown. This
* exception will include as its {@link Throwable#getCause() cause} either
* <ol>
* <li>any {@link java.rmi.NoSuchObjectException} that was caught</li>
* <li>or, if no {@link java.rmi.NoSuchObjectException} that was caught,
* the exception thrown on the last failover attempt</li>
* </ol>
* Preference is given to including <code>NoSuchObjectException</code> as
* the cause, as that exception indicates that a server was listening on
* the expected address and port but that this client has an RMI stub that
* is out of sync with the server. This would typically happen due to
* a server restart or service redeploy. Knowledge of this failure condition
* could potentially be useful to the caller.
* </p>
*
* @param proxy the proxy object that's being invoked
* @param method the method to invoke
* @param args arguments to the method
* @return any return value from the invocation, or <code>null</code>
*
* @throws Throwable Throwable thrown when making remote call, or the
* <code>RemoteException</code> discussed above.
*/
public Object invokeRemote(Object proxy, Method method, Object[] args) throws Throwable
{
boolean trace = log.isTraceEnabled();
HARMIServer target = (HARMIServer)getRemoteTarget();
NoSuchObjectException nsoe = null;
Exception lastException = null;
while (target != null)
{
try
{
if( trace )
log.trace("Invoking on target="+target);
MarshalledInvocation mi = new MarshalledInvocation(null, method, args, null, null, null);
mi.setObjectName (""); //FIXME: Fake value! Bill's optimisations regarding MI make the hypothesis
// that ObjectName is always here otherwise the writeExternal code of MI
// "out.writeInt(payload.size() - 3);" is wrong
HARMIResponse rsp = target.invoke(this.familyClusterInfo.getCurrentViewId (), mi);
if (rsp.newReplicants != null)
{
if( trace )
{
log.trace("newReplicants: "+rsp.newReplicants);
}
updateClusterInfo (rsp.newReplicants, rsp.currentViewId);
//setTargets(rsp.newReplicants);
//currentViewId = rsp.currentViewId;
}
return rsp.response;
}
catch (ConnectException e)
{
lastException = e;
}
catch (ConnectIOException e)
{
lastException = e;
}
catch (NoSuchObjectException e)
{
// JBAS-4740 preserve this exception
nsoe = e;
lastException = e;
}
catch (UnknownHostException e)
{
lastException = e;
}
if( trace )
log.trace("Invoke failed, target="+target, lastException);
// If we reach here, this means that we must fail-over
remoteTargetHasFailed(target);
target = (HARMIServer)getRemoteTarget();
}
// if we get here this means list was exhausted
// JBAS-4740 wrap any NSOE in preference to 'lastException' since
// an NSOE indicates a server was running
Exception toWrap = (nsoe == null) ? lastException : nsoe;
throw new java.rmi.RemoteException("Service unavailable.", toWrap);
}
// HARMIProxy implementation ----------------------------------------------
public boolean isLocal()
{
return local != null;
}
// InvocationHandler implementation ----------------------------------------------
/**
* Invoke the given method, locally if possible; if not then
* {@link #invokeRemote(Object, Method, Object[]) invoke against a remote server}.
*
* @see #invokeRemote(Object, Method, Object[])
*/
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable
{
// The isLocal call is handled by the proxy
String name = method.getName();
if (method.equals(TO_STRING))
{
StringBuffer tmp = new StringBuffer(super.toString());
tmp.append('(');
tmp.append(familyClusterInfo);
tmp.append(')');
return tmp.toString();
}
else if (name.equals("equals"))
{
return method.invoke(this, args);
}
else if (name.equals("hashCode"))
{
return method.invoke(this, args);
}
else if (name.equals("isLocal") && (args == null || args.length == 0))
{
return method.invoke(this, args);
}
// we try to optimize the call locally first
//
if (local != null)
{
try
{
Method localMethod = findLocalMethod(method, args);
return localMethod.invoke(local, args);
}
catch (java.lang.reflect.InvocationTargetException ite)
{
throw ite.getTargetException();
}
}
else
{
return invokeRemote(null, method, args);
}
}
// Package protected ---------------------------------------------
// Protected -----------------------------------------------------
protected void removeDeadTarget(Object target)
{
//System.out.println("Size before : " + Integer.toString(targets.length));
if (this.familyClusterInfo != null)
this.familyClusterInfo.removeDeadTarget (target);
}
// Private -------------------------------------------------------
private void readObject (ObjectInputStream stream)
throws IOException, ClassNotFoundException
{
this.key = stream.readUTF();
List<?> targets = (List<?>)stream.readObject();
long vid = stream.readLong ();
this.loadBalancePolicy = (LoadBalancePolicy)stream.readObject();
HARMIServer server = (HARMIServer)HARMIServer.rmiServers.get(key);
// keep a reference on our family object
//
this.familyClusterInfo = ClusteringTargetsRepository.initTarget (this.key, targets, vid);
if (this.loadBalancePolicy instanceof org.jboss.ha.framework.interfaces.LoadBalancePolicy)
{
((org.jboss.ha.framework.interfaces.LoadBalancePolicy)this.loadBalancePolicy).init(this);
}
if (server != null)
{
synchronized (targets)
{
try
{
targets = (List<?>)server.getReplicants();
local = server.getLocal();
}
catch (Exception ignored)
{}
}
}
this.trace = log.isTraceEnabled();
if( trace )
log.trace("Init, clusterInfo: "+familyClusterInfo+", policy="+loadBalancePolicy);
}
@SuppressWarnings("unchecked")
private void writeObject (ObjectOutputStream stream)
throws IOException
{
// JBAS-2071 - sync on FCI to ensure targets and vid are consistent
ArrayList currentTargets = null;
long vid = 0;
synchronized (this.familyClusterInfo)
{
// JBAS-6345 -- write an ArrayList for compatibility with AS 3.x/4.x clients
currentTargets = new ArrayList(this.familyClusterInfo.getTargets());
vid = this.familyClusterInfo.getCurrentViewId ();
}
stream.writeUTF(key);
stream.writeObject(currentTargets);
stream.writeLong(vid);
stream.writeObject(loadBalancePolicy);
}
}