org.lsst.ccs.framework

Interface ClearAlertHandler

All Superinterfaces:

AlertHandler

All Known Subinterfaces:

Monitor.AlarmHandler

All Known Implementing Classes:

AgentPeriodicTaskService, ConfigurationService, RuntimeService

public interface ClearAlertHandler
extends AlertHandler

Interface to be implemented by all classes that handle Alert clearing. These classes have to register themselves with a Subsystem. Multiple handlers can be registered with a given subsystem. ClearAlertHandlers will be called back with the instance of the Alert to be cleared. The handler has to assess if it is ok for the Subsystem to clear the status of a given Alert. When clearing an Alert instance the handlers will be called in order and depending on the return code the following actions will be taken:

• UNKWOWN_ALERT: this handler does not recognize the alert. The framework will move the the next handler.
• CLEAR_ALERT: it is ok to clear the alert. The framework will clear the alert if no other handler vetos the clearing.
• DONT_CLEAR_ALERT: the Alert is still valid and it should not be cleared. The framework will not clear the alert and stop looping over the registered handlers.

Author:

The LSST CCS Team

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	ClearAlertHandler.ClearAlertCode Enumeration of codes returned when the canClearAlert method is invoked.

Method Summary

Modifier and Type	Method and Description
ClearAlertHandler.ClearAlertCode	canClearAlert(Alert alert) Callback to clear an Alert instance.

Method Detail

canClearAlert

ClearAlertHandler.ClearAlertCode canClearAlert(Alert alert)

Callback to clear an Alert instance. Return true/false if the Alert can be cleared. When true is returned the Alert is cleared and no more handlers will be checked. When false is returned other handlers will be handed the Alert instance to be cleared. If no handler returns true, the Alert will not be cleared.

Parameters:

alert - The Alert instance to clear.

Returns:

A ClearAlertCode to indicate which action is to be taken by the framework.