/*
* 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.invocation.http.server;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.HashMap;
import javax.management.InstanceNotFoundException;
import javax.management.ObjectName;
import javax.management.ReflectionException;
import org.jboss.mx.util.JMXExceptionDecoder;
import org.jboss.ha.framework.interfaces.HARMIResponse;
import org.jboss.ha.framework.server.HATarget;
import org.jboss.ha.framework.interfaces.LoadBalancePolicy;
import org.jboss.ha.framework.interfaces.GenericClusteringException;
import org.jboss.invocation.http.interfaces.HttpInvokerProxyHA;
import org.jboss.invocation.Invocation;
import org.jboss.invocation.Invoker;
import org.jboss.invocation.InvokerHA;
import org.jboss.system.Registry;
/** An extension of the HttpInvoker and supports clustering of HTTP invokers.
*
* @author <a href="mailto:scott.stark@jboss.org>Scott Stark</a>
* @version $Revision: 105943 $
*/
public class HttpInvokerHA extends HttpInvoker
implements InvokerHA
{
protected HashMap<Integer, HATarget> targetMap = new HashMap<Integer, HATarget>();
// Public --------------------------------------------------------
protected void startService()
throws Exception
{
// Export the Invoker interface
ObjectName name = super.getServiceName();
Registry.bind(name, this);
// Make sure the invoker URL is valid
super.checkInvokerURL();
log.debug("Bound HttpHA invoker for JMX node");
}
protected void stopService()
{
// Unxport the Invoker interface
ObjectName name = super.getServiceName();
Registry.unbind(name);
log.debug("Unbound HttpHA invoker for JMX node");
}
protected void destroyService()
{
// Export references to the bean
Registry.unbind(serviceName);
}
public void registerBean(ObjectName targetName, HATarget target) throws Exception
{
Integer hash = new Integer(targetName.hashCode());
log.debug("Registered targetName("+targetName+"), hash="+hash
+ ", target="+target);
if (targetMap.containsKey(hash))
{
throw new IllegalStateException("Duplicate targetName("+targetName
+ ") hashCode: "+hash);
}
targetMap.put(hash, target);
}
public void unregisterBean(ObjectName targetName) throws Exception
{
Integer hash = new Integer(targetName.hashCode());
targetMap.remove(hash);
log.debug("Unregistered targetName("+targetName+"), hash="+hash);
}
public Invoker createProxy(ObjectName targetName, LoadBalancePolicy policy,
String proxyFamilyName)
throws Exception
{
Integer hash = new Integer(targetName.hashCode());
HATarget target = (HATarget) targetMap.get(hash);
if (target == null)
{
throw new IllegalStateException("The targetName("+targetName
+ "), hashCode("+hash+") not found");
}
Invoker proxy = new HttpInvokerProxyHA(target.getReplicantList(), target.getCurrentViewId (),
policy, proxyFamilyName);
return proxy;
}
public Serializable getStub()
{
return super.getInvokerURL();
}
/**
* Invoke a Remote interface method.
*/
public Object invoke(Invocation invocation)
throws Exception
{
ClassLoader oldCl = Thread.currentThread().getContextClassLoader();
try
{
// Extract the ObjectName, the rest is still marshalled
ObjectName mbean = (ObjectName) Registry.lookup(invocation.getObjectName());
long clientViewId = ((Long)invocation.getValue("CLUSTER_VIEW_ID")).longValue();
HATarget target = targetMap.get(invocation.getObjectName());
if (target == null)
{
// We could throw IllegalStateException but we have a race condition that could occur:
// when we undeploy a bean, the cluster takes some time to converge
// and to recalculate a new viewId and list of replicant for each HATarget.
// Consequently, a client could own an up-to-date list of the replicants
// (before the cluster has converged) and try to perform an invocation
// on this node where the HATarget no more exist, thus receiving a
// wrong exception and no failover is performed with an IllegalStateException
//
throw new GenericClusteringException(GenericClusteringException.COMPLETED_NO,
"target is not/no more registered on this node");
}
if (!target.invocationsAllowed ())
throw new GenericClusteringException(GenericClusteringException.COMPLETED_NO,
"invocations are currently not allowed on this target");
// The cl on the thread should be set in another interceptor
Object[] args = {invocation};
String[] sig = {"org.jboss.invocation.Invocation"};
Object rtn = super.getServer().invoke(mbean,
"invoke", args, sig);
// Update the targets list if the client view is out of date
HARMIResponse rsp = new HARMIResponse();
if (clientViewId != target.getCurrentViewId())
{
rsp.newReplicants = new ArrayList<Object>(target.getReplicantList());
rsp.currentViewId = target.getCurrentViewId();
}
rsp.response = rtn;
// Return the raw object and let the http layer marshall it
return rsp;
}
catch (InstanceNotFoundException e)
{
throw new GenericClusteringException(GenericClusteringException.COMPLETED_NO, e);
}
catch (ReflectionException e)
{
throw new GenericClusteringException(GenericClusteringException.COMPLETED_NO, e);
}
catch(Exception e)
{
JMXExceptionDecoder.rethrow(e);
// the compiler does not know an exception is thrown by the above
throw new org.jboss.util.UnreachableStatementException();
}
finally
{
Thread.currentThread().setContextClassLoader(oldCl);
}
}
}