org.opennms.netmgt.poller.monitors
Class LoopMonitor

java.lang.Object
  org.opennms.netmgt.poller.monitors.LoopMonitor

All Implemented Interfaces:

ServiceMonitor

@Distributable
public class LoopMonitor
extends Object
implements ServiceMonitor

Author:

david

Constructor Summary

LoopMonitor()

Method Summary

void	initialize(Map parameters) This method is called after the framework creates an instance of the plug-in.
void	initialize(MonitoredService svc) This method is called whenever a new interface that supports the plug-in service is added to the scheduling system.
PollStatus	poll(MonitoredService svc, Map parameters) This method is the heart of the plug-in monitor.
void	release() This method is called whenever the plug-in is being unloaded, normally during framework exit.
void	release(MonitoredService svc) This method is the called whenever an interface is being removed from the scheduler.

Methods inherited from class java.lang.Object

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

Constructor Detail

LoopMonitor

public LoopMonitor()

Method Detail

initialize

public void initialize(Map parameters)

Description copied from interface: ServiceMonitor

This method is called after the framework creates an instance of the plug-in. The framework passes the object a proxy object that can be used to retrieve configuration information specific to the plug-in. Additionally, any parameters for the plug-in from the package definition are passed using the parameters element.

If there is a critical error, like missing service libraries, the the Monitor may throw a ServiceMonitorException. If the plug-in throws an exception then the plug-in will be disabled in the framework.

Specified by:

initialize in interface ServiceMonitor

Parameters:

parameters - Not currently used

release

public void release()

Description copied from interface: ServiceMonitor

This method is called whenever the plug-in is being unloaded, normally during framework exit. During this time the framework may release any resource and save any state information using the proxy object from the initialization routine.

Even if the plug-in throws a monitor exception, it will not prevent the plug-in from being unloaded. The plug-in should not return until all of its state information is saved. Once the plug-in returns from this call its configuration proxy object is considered invalid.

Specified by:

release in interface ServiceMonitor

initialize

public void initialize(MonitoredService svc)

Description copied from interface: ServiceMonitor

This method is called whenever a new interface that supports the plug-in service is added to the scheduling system. The plug-in has the option to load and/or associate configuration information with the interface before the framework begins scheduling the new device.

Should a monitor exception be thrown during an initialization call then the framework will log an error and discard the interface from scheduling.

Specified by:

initialize in interface ServiceMonitor

Parameters:

svc - TODO

release

public void release(MonitoredService svc)

Description copied from interface: ServiceMonitor

This method is the called whenever an interface is being removed from the scheduler. For example, if a service is determined as being no longer supported then this method will be invoked to cleanup any information associated with this device. This gives the implementor of the interface the ability to serialize any data prior to the interface being discarded.

If an exception is thrown during the release the exception will be logged, but the interface will still be discarded for garbage collection.

Specified by:

release in interface ServiceMonitor

Parameters:

svc - TODO

poll

public PollStatus poll(MonitoredService svc,
                       Map parameters)

Description copied from interface: ServiceMonitor

This method is the heart of the plug-in monitor. Each time an interface requires a check to be performed as defined by the scheduler the poll method is invoked. The poll is passed the interface to check

By default when the status transition from up to down or vice versa the framework will generate an event. Additionally, if the polling interval changes due to an extended unavailability, the framework will generate an additional down event. The plug-in can suppress the generation of the default events by setting the suppress event bit in the returned integer.

Specified by:

poll in interface ServiceMonitor

Parameters:

svc - TODO

parameters - The package parameters (timeout, retry, etc...) to be used for this poll.

Returns:

The availability of the interface and if a transition event should be suppressed.

See Also:

PollStatus.SERVICE_AVAILABLE, PollStatus.SERVICE_UNAVAILABLE