org.xmlBlaster.protocol.rmi
Class RmiDriver

java.lang.Object
  org.xmlBlaster.protocol.rmi.RmiDriver

All Implemented Interfaces:

I_Driver, I_Plugin

public class RmiDriver

extends java.lang.Object

implements I_Driver

RmiDriver class to invoke the xmlBlaster server using RMI.

Design issues:

How to identify the calling client.

How does RMI handle incoming requests?
Is it a worker thread model, or a 1 client/one thread model, or 1 worker thread per RMI call? When a call comes in a random thread is taken from a pool.
According to the rmi specs "A method dispatched by the RMI runtime to a remote object implementation (a server) may or may not execute in a separate thread. Some calls originating from the same client virtual machine will execute in the same thread; some will execute in different threads. Calls originating from different client virtual machines will execute in different threads. Other than this last case of different client virtual machines, the RMI runtime makes no guarantees with respect to mapping remote object invocations to threads. "

Possible soultions:

• Give each client its own remote object to call
  We can implicitly identiofy the client, but we will have problems with many connecting clients because of the 1-1 mapping between threads and sockets.
• Pass the sessionId with each method call
  Implicitly this will be one server object serving all clients It is not very smart
• Hack rmic to automatically pass a client id

We will choose the second solution (pass the sessionId).

RMI has not fine controlled policy like the CORBA POA!

A rmi-registry server is created automatically, if there is running already one, that is used.
You can specify another port or host to create/use a rmi-registry server:

     -plugin/rmi/registryPort   Specify a port number where rmiregistry listens.
                         Default is port 1099, the port 0 switches this feature off.
     -plugin/rmi/hostname Specify a hostname where rmiregistry runs.
                         Default is the localhost.
 

Invoke options:

   java -Djava.rmi.server.codebase=file:///${XMLBLASTER_HOME}/classes/  \
        -Djava.security.policy=${XMLBLASTER_HOME}/config/xmlBlaster.policy \
        -Djava.rmi.server.hostname=hostname.domainname
        MyApp -plugin/rmi/registryPort 2078
 

Another option is to include the directory of xmlBlaster.policy into your CLASSPATH.

See Also:

The RMI requirement, RMI FAQ, RMI USERS

Field Summary

private AddressServer	addressServer The protocol plugin configuration
private java.lang.String	authBindName The name for the RMI registry
private I_Authenticate	authenticate The singleton handle for this xmlBlaster server
private AuthServerImpl	authRmiServer The RMI implementation, which delegates to authenticate
static int	DEFAULT_REGISTRY_PORT XmlBlaster RMI registry listen port is 1099, to access for bootstrapping
private Global	glob
private boolean	isActive
private static java.util.logging.Logger	log
private java.lang.String	ME
private java.lang.String	xmlBlasterBindName The name for the RMI registry
private I_XmlBlaster	xmlBlasterImpl The singleton handle for this xmlBlaster server
private XmlBlasterImpl	xmlBlasterRmiServer The RMI implementation, which delegates to xmlBlaster server

Constructor Summary

RmiDriver()

Method Summary

void	activate() Activate xmlBlaster access through this protocol.
private void	bindToRegistry() Publish the RMI xmlBlaster server to rmi registry.
void	deActivate() Deactivate xmlBlaster access (standby), no clients can connect.
java.lang.String	getName() Get a human readable name of this driver
java.lang.String	getProtocolId() Access the xmlBlaster internal name of the protocol driver.
java.lang.String	getRawAddress() Get the address how to access this driver.
java.lang.String	getType() Enforced by I_Plugin
java.lang.String	getVersion() Enforced by I_Plugin
private void	init(Global glob, AddressServer addressServer, I_Authenticate authenticate, I_XmlBlaster xmlBlasterImpl) Start xmlBlaster RMI access.
void	init(Global glob, PluginInfo pluginInfo) This method is called by the PluginManager (enforced by I_Plugin).
void	shutdown() Instructs RMI to shut down.
java.lang.String	usage() Command line usage.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ME

private java.lang.String ME

glob

private Global glob

log

private static java.util.logging.Logger log

DEFAULT_REGISTRY_PORT

public static final int DEFAULT_REGISTRY_PORT

XmlBlaster RMI registry listen port is 1099, to access for bootstrapping

See Also:

Constant Field Values

authenticate

private I_Authenticate authenticate

The singleton handle for this xmlBlaster server

xmlBlasterImpl

private I_XmlBlaster xmlBlasterImpl

The singleton handle for this xmlBlaster server

authRmiServer

private AuthServerImpl authRmiServer

The RMI implementation, which delegates to authenticate

authBindName

private java.lang.String authBindName

The name for the RMI registry

xmlBlasterRmiServer

private XmlBlasterImpl xmlBlasterRmiServer

The RMI implementation, which delegates to xmlBlaster server

xmlBlasterBindName

private java.lang.String xmlBlasterBindName

The name for the RMI registry

isActive

private boolean isActive

addressServer

private AddressServer addressServer

The protocol plugin configuration

Constructor Detail

RmiDriver

public RmiDriver()

Method Detail

getName

public java.lang.String getName()

Get a human readable name of this driver

Specified by:

getName in interface I_Driver

getProtocolId

public java.lang.String getProtocolId()

Access the xmlBlaster internal name of the protocol driver.

Specified by:

getProtocolId in interface I_Driver

Returns:

"RMI"

getType

public java.lang.String getType()

Enforced by I_Plugin

Specified by:

getType in interface I_Plugin

getVersion

public java.lang.String getVersion()

Enforced by I_Plugin

Specified by:

getVersion in interface I_Plugin

init

public void init(Global glob,
                 PluginInfo pluginInfo)
          throws XmlBlasterException

This method is called by the PluginManager (enforced by I_Plugin).

Specified by:

init in interface I_Plugin

Throws:

XmlBlasterException

See Also:

I_Plugin.init(org.xmlBlaster.util.Global,org.xmlBlaster.util.plugin.PluginInfo)

getRawAddress

public java.lang.String getRawAddress()

Get the address how to access this driver.

Specified by:

getRawAddress in interface I_Driver

Returns:

"rmi://www.mars.universe:1099/I_AuthServer"

init

private void init(Global glob,
                  AddressServer addressServer,
                  I_Authenticate authenticate,
                  I_XmlBlaster xmlBlasterImpl)
           throws XmlBlasterException

Start xmlBlaster RMI access.

Parameters:

glob - Global handle to access logging, property and commandline args

Throws:

XmlBlasterException

activate

public void activate()
              throws XmlBlasterException

Activate xmlBlaster access through this protocol.

Specified by:

activate in interface I_Driver

Throws:

XmlBlasterException

deActivate

public void deActivate()
                throws XmlBlasterException

Deactivate xmlBlaster access (standby), no clients can connect.

Specified by:

deActivate in interface I_Driver

Throws:

XmlBlasterException

shutdown

public void shutdown()
              throws XmlBlasterException

Instructs RMI to shut down.

Specified by:

shutdown in interface I_Plugin

Throws:

XmlBlasterException - if an exception occurs. The exception is handled by the RunLevelManager depending on how the plugin has been configured with the action:

<action do='STOP' onShutdownRunlevel='2' sequence='5' onFail='resource.configuration.pluginFailed'> If onFail is defined to something, the RunLevelManager will stop.

bindToRegistry

private void bindToRegistry()
                     throws XmlBlasterException

Publish the RMI xmlBlaster server to rmi registry.

The bind name is typically "rmi://localhost:1099/xmlBlaster"

Throws:

XmlBlasterException - RMI registry error handling

usage

public java.lang.String usage()

Command line usage.

Specified by:

usage in interface I_Driver