edu.umass.cs.reconfiguration.reconfigurationutils

Class AbstractDemandProfile

java.lang.Object

edu.umass.cs.reconfiguration.reconfigurationutils.AbstractDemandProfile

Direct Known Subclasses:

DemandProfile

public abstract class AbstractDemandProfile
extends java.lang.Object

Author:

V. Arun An implementation, X, of this abstract class must satisfy the following requirements in addition to those enforced by the abstract methods explicitly listed herein: (1) X must have a constructor that takes a single JSONObject as an argument. Otherwise, the static method createDemandProfile(JSONObject) that reflectively creates an instance of this class from a JSONObject will fail. (2) X must have a constructor that takes a single String as an argument. Otherwise, the static method createDemandProfile(String) that reflectively creates an instance of this class from a JSONObject will fail. (3) For any instance x of X, x.equals(new X(x.getStats()) must return true. (4) It is slightly more efficient (but not necessary) for X to override the methods createDemandProfile(String) and createDemandProfile(JSONObject) method to create an instance of X rather than having the default implementation do so via reflection. Refer to reconfiguration.reconfigurationutils.DemandProfile for an example implementation. Use ReconfigurationPolicyTest.testPolicyImplementation(Class) to test an implementation of this class.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	AbstractDemandProfile.Keys

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.String	name

Constructor Summary

Constructors

Constructor and Description
AbstractDemandProfile(java.lang.String name)

Method Summary

Modifier and Type	Method and Description
AbstractDemandProfile	clone() Deprecated.
abstract void	combine(AbstractDemandProfile update) Combine the new information in update into this.
protected static AbstractDemandProfile	createDemandProfile(java.lang.Class<?> clazz, java.lang.String name)
static AbstractDemandProfile	createDemandProfile(org.json.JSONObject json)
protected static AbstractDemandProfile	createDemandProfile(java.lang.String name)
abstract org.json.JSONObject	getDemandStats() All relevant stats must be serializable into JSONObject.
java.lang.String	getName()
abstract void	justReconfigured() Tells this that the current demand profile was just used to perform reconfiguration.
abstract java.util.Set<java.lang.String>	reconfigure(java.util.Set<java.lang.String> curActives, ReconfigurableAppInfo appInfo) The main reconfiguration policy invoked at reconfigurators (not active replicas).
void	reset() Deprecated.
abstract boolean	shouldReportDemandStats(Request request, java.net.InetAddress sender, ReconfigurableAppInfo nodeConfig) This method incorporates new information about client requests, i.e., request was received from sender.

Methods inherited from class java.lang.Object

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

Field Detail

name

protected final java.lang.String name

Constructor Detail

AbstractDemandProfile

public AbstractDemandProfile(java.lang.String name)

Parameters:

name - The service name of the reconfiguree replica group.

Method Detail

shouldReportDemandStats

public abstract boolean shouldReportDemandStats(Request request,
                                                java.net.InetAddress sender,
                                                ReconfigurableAppInfo nodeConfig)

This method incorporates new information about client requests, i.e., request was received from sender. The list of all active replicas can be obtained from ReconfigurableAppInfo.getAllActiveReplicas() ; this may be useful to determine whether other active replicas might be better suited to service requests from this sender. This method must implement a policy that tells whether it is time to report from an active replica to a reconfigurator. Active replicas in general should not report upon every request, but at some coarser frequency to limit overhead.

Parameters:

request -

sender -

nodeConfig -

Returns:

Whether the active replica should send a demand report to the reconfigurator.

getDemandStats

public abstract org.json.JSONObject getDemandStats()

All relevant stats must be serializable into JSONObject. Any information not included in the returned JSONObject will not be available for use in the reconfiguration policy in reconfigure(Set, ReconfigurableAppInfo) that is invoked at reconfigurators (not active replicas).

Returns:

Demand statistics as JSON.

combine

public abstract void combine(AbstractDemandProfile update)

Combine the new information in update into this. This method is used at reconfigurators to combine a newly received demand report with an existing demand report.

Parameters:

update -

reconfigure

public abstract java.util.Set<java.lang.String> reconfigure(java.util.Set<java.lang.String> curActives,
                                                            ReconfigurableAppInfo appInfo)

The main reconfiguration policy invoked at reconfigurators (not active replicas).

Parameters:

curActives -

nodeConfig -

Returns:

The list of reconfigured actives for the new placement. Simply returning null means no reconfiguration will happen. Returning a list that is the same as curActives means that a trivial reconfiguration will happen unless ReconfigurationConfig.RC.RECONFIGURE_IN_PLACE is set to false.

justReconfigured

public abstract void justReconfigured()

Tells this that the current demand profile was just used to perform reconfiguration. This information is useful for implementing policies based on the difference between the current demand profile and the one at the time of the most recent reconfiguration, e.g., reconfigure only if the demand from some region has changed by more than 10%.

getName

public final java.lang.String getName()

Returns:

Name of reconfiguree.

clone

@Deprecated
public AbstractDemandProfile clone()

Deprecated.

Creates a deep copy of this object. So, it must be the case that the return value != this, but the return value.equals(this). You may also need to override equals(.) and hashCode() methods accordingly. If an implementation of this class consists of non-primitive types, e.g., a Map, then a new Map has to be created inside the clone() method.

Overrides:

clone in class java.lang.Object

reset

@Deprecated
public void reset()

Deprecated.

Clear all info, i.e., forget all previous stats.

createDemandProfile

protected static AbstractDemandProfile createDemandProfile(java.lang.String name)

createDemandProfile

protected static AbstractDemandProfile createDemandProfile(java.lang.Class<?> clazz,
                                                           java.lang.String name)

createDemandProfile

public static AbstractDemandProfile createDemandProfile(org.json.JSONObject json)

Parameters:

json -

Returns:

Reflection-based constructor to create demand profile.