Rio Project 4.2 API Documentation

org.rioproject.monitor
Class ServiceResourceSelector

java.lang.Object
  org.rioproject.monitor.ServiceResourceSelector

All Implemented Interfaces:

LeaseListener

Direct Known Subclasses:

LeastActiveSelector, ResourceCostSelector, RoundRobinSelector

public abstract class ServiceResourceSelector
extends Object
implements LeaseListener

This abstract class defines the semantics for selecting a ServiceResource based on requirements contained within a ServiceElement. Additionally, this interface defines semantics for the removal and snapshot retrieval of ServiceResource objects under its control.

Objects which implement this interface will need to create a Collection to manage the ServiceResource elements it is notified of. The managed Collection will back the Collection of ServiceResource elements which are leased and managed by the LandlordLessor

The LandlordLessor will send notifications of the following:

• Notifies the manager of a lease expiration
• Notifies the manager of a new lease being created
• Notifies the manager of a lease being renewed

It is the responsibility of the entity to register with the LandlordLessor. The object that implements this interface should define the actions to take upon receipt of such notifications

Concrete implementations of this class must provide a zero-argument constructor in order to be instantiated by the ProvisionMonitor

Author:

Dennis Reedy

Field Summary

protected Collection<LeasedResource>	collection The collection of ServiceResource objects to manage
protected Object	collectionLock
protected LandlordLessor	landlord The LandlordLessor which will be registered to, and will provide Lease notification events

Constructor Summary

ServiceResourceSelector()

Method Summary

protected void	add(LeasedResource resource) If the Collection backed by the concrete class requires processing other then that defined by Collection.add override this method to provide the appropriate semantics
void	expired(LeasedResource resource) Notifies the manager of a lease expiration
ServiceResource	getServiceResource(ServiceElement sElem) This method will attempt to identify an available ServiceResource based on the operational criteria specified by a ServiceBean
ServiceResource	getServiceResource(ServiceElement sElem, Uuid uuid, boolean inclusive) This method will attempt to identify an available ServiceResource based on the operational criteria specified by a ServiceBean
ServiceResource[]	getServiceResources(ServiceElement sElem) Get all available ServiceResource instances that support the ServiceElement object's contained requirement specifications
void	register(LeasedResource resource) Notifies the manager of a new lease being created.
protected void	remove(LeasedResource resource) If the Collection backed by the concrete class requires processing other then that defined by Collection.remove override this method to provide the appropriate semantics
void	removed(LeasedResource resource) Notifies the manager of a lease removal
void	renewed(LeasedResource resource) Notifies the manager of a lease being renewed.
protected ServiceResource	selectServiceResource(ServiceElement sElem, ServiceResource[] svcResources) Select a ServiceResource for dynamic ServiceBean provisioning based on the operational criteria of a ServiceBean
abstract void	serviceResourceSelected(ServiceResource resource) This method allows concrete implementations of this class to order the Collection of ServiceResource instances based on a ServiceResource being selected
void	setLandlordLessor(LandlordLessor landlord) Set the LandlordLessor the ServiceResourceSelector will register to.
protected void	update(LeasedResource resource) If the Collection backed by the concrete class requires processing other then that defined by Collection.add override this method to provide the appropriate semantics

Methods inherited from class java.lang.Object

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

Field Detail

collection

protected Collection<LeasedResource> collection

The collection of ServiceResource objects to manage

collectionLock

protected final Object collectionLock

landlord

protected LandlordLessor landlord

The LandlordLessor which will be registered to, and will provide Lease notification events

Constructor Detail

ServiceResourceSelector

public ServiceResourceSelector()

Method Detail

setLandlordLessor

public void setLandlordLessor(LandlordLessor landlord)

Set the LandlordLessor the ServiceResourceSelector will register to.

Parameters:

landlord - The LandlordLessor

getServiceResource

public ServiceResource getServiceResource(ServiceElement sElem)
                                   throws Exception

This method will attempt to identify an available ServiceResource based on the operational criteria specified by a ServiceBean

Parameters:

sElem - The ServiceElement

Returns:

If a ServiceResource object can be identified, return the ServiceResource, otherwise return null

Throws:

Exception - If there are errors getting a ServiceResource

getServiceResource

public ServiceResource getServiceResource(ServiceElement sElem,
                                          Uuid uuid,
                                          boolean inclusive)
                                   throws Exception

This method will attempt to identify an available ServiceResource based on the operational criteria specified by a ServiceBean

Parameters:

sElem - The ServiceElement

uuid - The Uuid of the InstantiatorResource to either include or not include

inclusive - Either include or exclude the uuid from the selection. If true, include the uuid otherwise exclude the uuid

Returns:

If a ServiceResource object can be identified, otherwise return null

Throws:

Exception - if any errors occur selecting a resource

selectServiceResource

protected ServiceResource selectServiceResource(ServiceElement sElem,
                                                ServiceResource[] svcResources)
                                         throws ProvisionException

Select a ServiceResource for dynamic ServiceBean provisioning based on the operational criteria of a ServiceBean

Parameters:

sElem - The ServiceElement

svcResources - Array ServiceResource candidates

Returns:

If a ServiceResource object can be identified, otherwise return null

Throws:

ProvisionException - If there are unrecoverable errors provisioning the service

serviceResourceSelected

public abstract void serviceResourceSelected(ServiceResource resource)

This method allows concrete implementations of this class to order the Collection of ServiceResource instances based on a ServiceResource being selected

Parameters:

resource - A ServiceResource instance selected for provisioning a ServiceBean

getServiceResources

public ServiceResource[] getServiceResources(ServiceElement sElem)
                                      throws ProvisionException

Get all available ServiceResource instances that support the ServiceElement object's contained requirement specifications

Parameters:

sElem - The ServiceElement

Returns:

Array of ServiceResource instances that support the requirements

Throws:

ProvisionException - If there are unrecoverable errors provisioning the service

expired

public void expired(LeasedResource resource)

Notifies the manager of a lease expiration

Specified by:

expired in interface LeaseListener

Parameters:

resource - The resource associated with the expiration

removed

public void removed(LeasedResource resource)

Notifies the manager of a lease removal

Specified by:

removed in interface LeaseListener

Parameters:

resource - The resource associated with the removal

register

public void register(LeasedResource resource)

Notifies the manager of a new lease being created.

Specified by:

register in interface LeaseListener

Parameters:

resource - The resource associated with the new Lease.

renewed

public void renewed(LeasedResource resource)

Notifies the manager of a lease being renewed.

Specified by:

renewed in interface LeaseListener

Parameters:

resource - The resource associated with the new Lease.

add

protected void add(LeasedResource resource)

If the Collection backed by the concrete class requires processing other then that defined by Collection.add override this method to provide the appropriate semantics

Parameters:

resource - The LeasedResource to add

remove

protected void remove(LeasedResource resource)

If the Collection backed by the concrete class requires processing other then that defined by Collection.remove override this method to provide the appropriate semantics

Parameters:

resource - The LeasedResource to remove

update

protected void update(LeasedResource resource)

If the Collection backed by the concrete class requires processing other then that defined by Collection.add override this method to provide the appropriate semantics

Parameters:

resource - The LeasedResource