Rio Project 4.2 API Documentation

org.rioproject.sla
Class ScalingPolicyHandler

java.lang.Object
  org.rioproject.sla.SLAPolicyHandler
      org.rioproject.sla.ScalingPolicyHandler

All Implemented Interfaces:

Remote, ServerProxyTrust, ServiceProvisionListener, ThresholdListener

public class ScalingPolicyHandler
extends SLAPolicyHandler
implements ServiceProvisionListener, ServerProxyTrust

The ScalingPolicyHandler will increment and optionally decrement instances of the ServiceBean it is associated to based on limits set for the SLA. The ScalingPolicyHandler will look for attributes set that can control it's operational behavior,.

The ScalingPolicyHandler supports the following configuration entries; where each configuration entry name is associated with the component name scalingPolicyHandler

provisionListenerExporter

Type:	Exporter
Default:	A new BasicJeriExporter with a TcpServerEndpoint created on a random port, a BasicILFactory, distributed garbage collection turned off, keep alive on.
Description:	The Exporter used to export the ProvisionListener server. A new exporter is obtained every time a ScalablePolicyHandler needs to export itself.

Author:

Dennis Reedy

Field Summary

static String	DECREMENT_DESTROY_SENT Action that indicates that a decrement command with destroy set to true has been sent
static String	DECREMENT_FAILED Action that indicates that a decrement command failed to be sent
static String	INCREMENT_FAILURE Action that indicates an increment request has failed
static String	INCREMENT_PENDING Action that indicates an increment request is pending
static String	INCREMENT_SUCCEEDED Action that indicates an increment request has succeeded.
protected Calculable	lastCalculable The last calculable
protected ThresholdValues	lastThresholdValues The last ThresholdValue
protected int	maxServices The maximum number of services to increment.

Fields inherited from class org.rioproject.sla.SLAPolicyHandler

context, eventSource, initialized, thresholdManager

Constructor Summary

ScalingPolicyHandler(SLA sla)
Construct a ScalingPolicyHandler

Method Summary

void	disconnect() Disconnect from the ThresholdManager
protected boolean	doDecrement() Do the decrement
protected void	doIncrement() Do the increment
void	failed(ServiceElement sElem, boolean resubmitted) Notify listener that the Service described by the ServiceElement has not been provision succesfully
String	getDescription() Get the description
protected int	getPendingRequestCount(OperationalStringManager opMgr)
TrustVerifier	getProxyVerifier() Returns a TrustVerifier which can be used to verify that a given proxy to this policy handler can be trusted
protected ServiceElement	getServiceElement()
protected int	getTotalKnownServices()
void	initialize(Object eventSource, EventHandler eventHandler, ServiceBeanContext context) Prepare the SLAPolicyHandler for processing.
void	notify(Calculable calculable, ThresholdValues thresholdValues, int type) Notify for a threshold event
void	setSLA(SLA sla) Set or update the SLA
void	setThresholdManager(ThresholdManager thresholdManager) Set the ThresholdManager and connect to the ThresholdManager
void	succeeded(ServiceBeanInstance jsbInstance) Notify listener that the Service described by the ServiceBeanInstance has been provisioned succesfully

Methods inherited from class org.rioproject.sla.SLAPolicyHandler

getConfiguration, getEventSource, getID, getName, getSLA, getThresholdManager, notifyListeners, registerListener, sendSLAThresholdEvent, setName, unregisterListener

Methods inherited from class java.lang.Object

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

Field Detail

INCREMENT_PENDING

public static final String INCREMENT_PENDING

Action that indicates an increment request is pending

See Also:

Constant Field Values

INCREMENT_FAILURE

public static final String INCREMENT_FAILURE

Action that indicates an increment request has failed

See Also:

Constant Field Values

INCREMENT_SUCCEEDED

public static final String INCREMENT_SUCCEEDED

Action that indicates an increment request has succeeded. The resultant Object in the SLAPolicyEvent will be the proxy of the new service

See Also:

Constant Field Values

DECREMENT_DESTROY_SENT

public static final String DECREMENT_DESTROY_SENT

Action that indicates that a decrement command with destroy set to true has been sent

See Also:

Constant Field Values

DECREMENT_FAILED

public static final String DECREMENT_FAILED

Action that indicates that a decrement command failed to be sent

See Also:

Constant Field Values

maxServices

protected int maxServices

The maximum number of services to increment. If the value is -1, then no limit has been set

lastCalculable

protected Calculable lastCalculable

The last calculable

lastThresholdValues

protected ThresholdValues lastThresholdValues

The last ThresholdValue

Constructor Detail

ScalingPolicyHandler

public ScalingPolicyHandler(SLA sla)

Construct a ScalingPolicyHandler

Parameters:

sla - The SLA for the ScalingPolicyHandler

Method Detail

getDescription

public String getDescription()

Description copied from class: SLAPolicyHandler

Get the description

Overrides:

getDescription in class SLAPolicyHandler

Returns:

String The descriptive attribute for this SLA Handler

setThresholdManager

public void setThresholdManager(ThresholdManager thresholdManager)

Description copied from interface: ThresholdListener

Set the ThresholdManager and connect to the ThresholdManager

Specified by:

setThresholdManager in interface ThresholdListener

Overrides:

setThresholdManager in class SLAPolicyHandler

Parameters:

thresholdManager - The ThresholdManager to connect to

See Also:

ThresholdListener.setThresholdManager(org.rioproject.watch.ThresholdManager)

disconnect

public void disconnect()

Description copied from class: SLAPolicyHandler

Disconnect from the ThresholdManager

Overrides:

disconnect in class SLAPolicyHandler

setSLA

public void setSLA(SLA sla)

Description copied from class: SLAPolicyHandler

Set or update the SLA

Overrides:

setSLA in class SLAPolicyHandler

Parameters:

sla - The SLA

initialize

public void initialize(Object eventSource,
                       EventHandler eventHandler,
                       ServiceBeanContext context)

Description copied from class: SLAPolicyHandler

Prepare the SLAPolicyHandler for processing. The method will only set these values if the SLAPolicyHandler has not been initialized before

Overrides:

initialize in class SLAPolicyHandler

Parameters:

eventSource - The object to be used as the remote event source

eventHandler - Handler which sends events

context - The ServiceBeanContext

getServiceElement

protected ServiceElement getServiceElement()

notify

public void notify(Calculable calculable,
                   ThresholdValues thresholdValues,
                   int type)

Description copied from interface: ThresholdListener

Notify for a threshold event

Specified by:

notify in interface ThresholdListener

Overrides:

notify in class SLAPolicyHandler

Parameters:

calculable - The current metric

thresholdValues - The current thresholds

type - The type of threshold event, breached or cleared

See Also:

ThresholdListener.notify(org.rioproject.watch.Calculable, org.rioproject.watch.ThresholdValues, int)

succeeded

public void succeeded(ServiceBeanInstance jsbInstance)
               throws RemoteException

Description copied from interface: ServiceProvisionListener

Notify listener that the Service described by the ServiceBeanInstance has been provisioned succesfully

Specified by:

succeeded in interface ServiceProvisionListener

Parameters:

jsbInstance - The ServiceBeanInstance

Throws:

RemoteException - If communication errors occur

See Also:

ServiceProvisionListener.succeeded(org.rioproject.core.ServiceBeanInstance)

failed

public void failed(ServiceElement sElem,
                   boolean resubmitted)
            throws RemoteException

Description copied from interface: ServiceProvisionListener

Notify listener that the Service described by the ServiceElement has not been provision succesfully

Specified by:

failed in interface ServiceProvisionListener

Parameters:

sElem - The ServiceElement

resubmitted - Whether the Service described by the ServiceElement has been resubmitted for provisioning

Throws:

RemoteException - If communication errors occur

See Also:

ServiceProvisionListener.failed(org.rioproject.core.ServiceElement, boolean)

getProxyVerifier

public TrustVerifier getProxyVerifier()

Returns a TrustVerifier which can be used to verify that a given proxy to this policy handler can be trusted

Specified by:

getProxyVerifier in interface ServerProxyTrust

getPendingRequestCount

protected int getPendingRequestCount(OperationalStringManager opMgr)

getTotalKnownServices

protected int getTotalKnownServices()
                             throws Exception

Throws:

Exception

doIncrement

protected void doIncrement()

Do the increment

doDecrement

protected boolean doDecrement()

Do the decrement

Returns:

true if the decrement needs to be rescheduled