org.objectweb.carol.cmi

Class DistributorHome

java.lang.Object

org.objectweb.carol.cmi.Distributor

org.objectweb.carol.cmi.DistributorHome

public abstract class DistributorHome
extends Distributor

Specific Distributor class for the Home interface load balancing and fail-over logic - default LB algorithm : -> local pref and round robin - default fail-over algorithm : -> retry on ConnectException or ConnectIOException or NoSuchObjectException

Author:

Benoit Pelletier

Constructor Summary

Constructors

Constructor and Description
DistributorHome()

Method Summary

Methods

Modifier and Type	Method and Description
StubData	choose(java.lang.reflect.Method method, java.lang.Object[] parameters) choose a stub according to the load balancing algorithm - first local preference - and then round robin The application can override this method
boolean	equivAtBind() To be overriden
boolean	equivAtExport() To be overriden
Decision	onException(java.lang.reflect.Method method, java.lang.Object[] parameters, StubData sd, java.lang.Exception ex) Decision on Exception : - retry on ConnectException or ConnectIOException or NoSuchObjectException The application deployer can override this method to make its own choices.
Decision	onReturn(java.lang.reflect.Method method, java.lang.Object[] parameters, StubData sd, java.lang.Object retVal) Decision on return For the SSB, the create method returns a ClusterStub containing a list of Remote stubs (singleton) With the preference local algorithm implemented by the choose method, the local remote stub is also taken in priority Below, the optimization consists not to return a Remote stubs list in this case but just the local Remote Stub.

Methods inherited from class org.objectweb.carol.cmi.Distributor

chooseLocalFirst, getCurrentState, getMyServerId, getStubList, preInvoke, read, removeStub, removeStub, toContentsString, toString, write

Methods inherited from class java.lang.Object

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

Constructor Detail

DistributorHome

public DistributorHome()

Method Detail

equivAtBind

public boolean equivAtBind()

Description copied from class: Distributor

To be overriden

Specified by:

equivAtBind in class Distributor

Returns:

true if the bound object have to be clustered

See Also:

The home stub associated with the jndi name has to be replicated at the bind() time

equivAtExport

public boolean equivAtExport()

Description copied from class: Distributor

To be overriden

Specified by:

equivAtExport in class Distributor

Returns:

true if the export object have to be clustered

See Also:

Distributor.equivAtExport()

choose

public StubData choose(java.lang.reflect.Method method,
              java.lang.Object[] parameters)
                throws NoServerException

choose a stub according to the load balancing algorithm - first local preference - and then round robin The application can override this method

Overrides:

choose in class Distributor

Parameters:

method - called method

parameters - method's parameters list

Returns:

chose stub

Throws:

NoServerException - if no more stub available

onReturn

public Decision onReturn(java.lang.reflect.Method method,
                java.lang.Object[] parameters,
                StubData sd,
                java.lang.Object retVal)

Decision on return For the SSB, the create method returns a ClusterStub containing a list of Remote stubs (singleton) With the preference local algorithm implemented by the choose method, the local remote stub is also taken in priority Below, the optimization consists not to return a Remote stubs list in this case but just the local Remote Stub. Thus, the LB step at the Remote interface is disabled when the SSB is created locally The application deployer can override this method to make its own choices.

Overrides:

onReturn in class Distributor

Parameters:

method - calling method

parameters - parameters of the calling method

sd - stub data

retVal - return value

Returns:

decision

onException

public Decision onException(java.lang.reflect.Method method,
                   java.lang.Object[] parameters,
                   StubData sd,
                   java.lang.Exception ex)

Decision on Exception : - retry on ConnectException or ConnectIOException or NoSuchObjectException The application deployer can override this method to make its own choices.

Overrides:

onException in class Distributor

Parameters:

method - calling method

parameters - parameters of the calling method

sd - stub data

ex - exception

Returns:

decision