jgroup.arm.recovery
Class AbstractRecoveryStrategy

java.lang.Object
  jgroup.arm.recovery.AbstractRecoveryStrategy

All Implemented Interfaces:

RecoveryStrategy

Direct Known Subclasses:

KeepMinimalInPartition

public abstract class AbstractRecoveryStrategy
extends java.lang.Object
implements RecoveryStrategy

This implements only the core initialization of a recovery strategy, including also handling for the RM recoveree replica.

Since:

Jgroup 1.2

Author:

Hein Meling

Field Summary

protected AppConfig	app The application associated with this recovery strategy instance
protected DistributionScheme	distScheme The distribution scheme interface
protected int	missing The current delta redundancy (the number of missing replicas)

Constructor Summary

AbstractRecoveryStrategy()
All recovery strategy implementations should implement a no-argument constructor.

Method Summary

protected int	deltaRedundancy(AppConfig app) Returns the number of replicas that needs to be recovered to maintain the minimal redundancy level specified.
void	initialize(DistributionScheme distScheme, AppConfig app) Initialize the recovery strategy for the given application.
boolean	needsRecovery() Returns true if the associated application needs a recovery action, otherwise false is returned.
boolean	prepareRecovery() Invoked to initialize the recovery strategy implementation for the provided application.

Methods inherited from class java.lang.Object

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

Methods inherited from interface jgroup.core.arm.RecoveryStrategy

handleFailure, relocateReplica, restartReplica

Field Detail

distScheme

protected DistributionScheme distScheme

The distribution scheme interface

app

protected AppConfig app

The application associated with this recovery strategy instance

missing

protected int missing

The current delta redundancy (the number of missing replicas)

Constructor Detail

AbstractRecoveryStrategy

public AbstractRecoveryStrategy()

All recovery strategy implementations should implement a no-argument constructor. This pattern cannot be enforced by the RecoveryStratgy interface, but can be check while parsing.

Method Detail

deltaRedundancy

protected int deltaRedundancy(AppConfig app)

Returns the number of replicas that needs to be recovered to maintain the minimal redundancy level specified. If no recovery is needed, zero is returned.

initialize

public void initialize(DistributionScheme distScheme,
                       AppConfig app)

Description copied from interface: RecoveryStrategy

Initialize the recovery strategy for the given application.

Specified by:

initialize in interface RecoveryStrategy

needsRecovery

public boolean needsRecovery()

Description copied from interface: RecoveryStrategy

Returns true if the associated application needs a recovery action, otherwise false is returned.

Specified by:

needsRecovery in interface RecoveryStrategy

prepareRecovery

public boolean prepareRecovery()

Description copied from interface: RecoveryStrategy

Invoked to initialize the recovery strategy implementation for the provided application. The method returns true if the group has failed.

Specified by:

prepareRecovery in interface RecoveryStrategy