Package RtjAocsFramework.FailureRecovery

This package defines the classes that support failure recovery management.

See:
Description

Interface Summary

FailureRecoveryModeManager

Interface characterizing the mode manager for the failure recovery manager.

Class Summary

FailureRecoveryManager	This class encapsulates a failure recovery manager.
FollowerFailureRecoveryModeManager	Encapsulation of a follower mode manager for the failure recovery manager.
LocalRecoveryActions	This recovery strategy retrieves from the event repository the failure events generated since the last call to doRecovery() and performs the recovery actions associated to each event.
ModeChange	This recovery action causes an operational mode change in a target mode manager.
NullRecoveryAction	A null recovery action is a dummy recovery action that takes no action.
ObjectReset	This recovery action causes an object to be reset (its reset() method is called).
Reconfiguration	This recovery action commands a reconfiguration to a reconfiguration manager.
RecoveryAction	This is the base class for recovery actions.
RecoveryStrategy	This is the base class for recovery strategies.
SystemReset	This recovery action commands a system reset by calling the "system reset" service on the system manager.
SystemResetOnConfigurationError	This recovery startegy will cause a software reset to be executed if a configuration event is detected in the configuration event repository.
SystemResetOnTooManyFailures	This recovery startegy will cause a software reset to be executed if the number of failure reports created since the last activation (or since the component was reset or initialized) is higher than a settable threshold.
TestCaseFailureRecovery_1	Test case for failure recovery management: check the following three recovery actions: mode change, reconfiguration, system reset, and reconfiguration.
TestCaseFailureRecovery_2	Test case for failure recovery management: check the following three recovery strategies: system reset on too many failures, local recovery actions and system reset on configuration error.
TestCaseFailureRecovery_3	Test case for failure recovery management: check the failure recovery manager (FRM).

Package RtjAocsFramework.FailureRecovery Description

This package defines the classes that support failure recovery management. Failure detection is based on the Failure Recovery Management design pattern.

The AOCS framework regards failure detection and failure recovery as separate functionalities allocated to distinct components. The failure detection component performs failure checks and, when it detects a failure, it creates an event that describes it and stores it in an event repository. The failure recovery component inspects the failure event repository to check whether any failures have been identified and then uses the information stored in the failure events to decide on the appropriate recovery action.

The objective of the failure recovery function is to react to reports of failure detections to try to remove the cause of a failure. The failure recovery function is implemented by a failure recovery manager. The failure recovery manager implements failure recovery at two levels. At the lower level, response to an individual failure report is implemented by performing one or more failure recovery actions. A failure recovery actions represent a local response to a failure. The response is said to be local because it is based on a single failure report. At a higher level, the failure recovery manager executes one or more failure recovery strategies. A failure recovery strategy encapsulates a set of coordinated responses to the failure events in the failure event repository. Unlike recovery actions, that act on individual failure reports, recovery strategies can take into considerations several failure reports and can therefore offer a higher-level response to failures.

More details on manoeuvre management can be found in the failure recovery management technical note.