com.redhat.thermostat.backend

Class VmPollingBackend

java.lang.Object

com.redhat.thermostat.backend.BaseBackend

com.redhat.thermostat.backend.VmPollingBackend

All Implemented Interfaces:

VmStatusListener, Backend, Ordered

public abstract class VmPollingBackend
extends BaseBackend
implements VmStatusListener

Convenience Backend class for implementations that will take some action for each monitored JVM process on a regular interval. Simply extend this class, implement any missing methods, and register one or more VmPollingAction implementations during instantiation.

Nested Class Summary

Nested classes/interfaces inherited from interface com.redhat.thermostat.agent.VmStatusListener

VmStatusListener.Status

Field Summary

Fields inherited from interface com.redhat.thermostat.common.Ordered

ORDER_CODE_GROUP, ORDER_CPU_GROUP, ORDER_DEFAULT_GROUP, ORDER_FIRST, ORDER_IO_GROUP, ORDER_LAST, ORDER_MEMORY_GROUP, ORDER_NETWORK_GROUP, ORDER_THREAD_GROUP, ORDER_USER_GROUP

Constructor Summary

Constructors

Constructor and Description
VmPollingBackend(String name, String description, String vendor, Version version, ScheduledExecutorService executor, VmStatusListenerRegistrar registrar)

Method Summary

Modifier and Type	Method and Description
boolean	activate() Activate the Backend.
boolean	deactivate() Deactivate the Backend.
boolean	isActive()
protected void	registerAction(VmPollingAction action) Register an action to be performed at each polling interval.
protected void	unregisterAction(VmPollingAction action) Unregister an action so that it will no longer be performed at each polling interval.
void	vmStatusChanged(VmStatusListener.Status newStatus, String vmId, int pid)

Methods inherited from class com.redhat.thermostat.backend.BaseBackend

equals, getDescription, getName, getObserveNewJvm, getVendor, getVersion, hashCode, setObserveNewJvm, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.redhat.thermostat.common.Ordered

getOrderValue

Constructor Detail

VmPollingBackend

public VmPollingBackend(String name,
                        String description,
                        String vendor,
                        Version version,
                        ScheduledExecutorService executor,
                        VmStatusListenerRegistrar registrar)

Method Detail

registerAction

protected final void registerAction(VmPollingAction action)

Register an action to be performed at each polling interval. It is recommended that implementations register all such actions during instantiation.

unregisterAction

protected final void unregisterAction(VmPollingAction action)

Unregister an action so that it will no longer be performed at each polling interval. If no such action has been registered, this method has no effect. Depending on thread timing issues, the action may be performed once even after this method has been called.

vmStatusChanged

public void vmStatusChanged(VmStatusListener.Status newStatus,
                            String vmId,
                            int pid)

Specified by:

vmStatusChanged in interface VmStatusListener

activate

public final boolean activate()

Description copied from interface: Backend

Activate the Backend. Based on the current configuration, begin pushing data to the Storage layer. If the Backend is already active, this method should have no effect.

This method is called by the framework when the Backend is registered.

Returns:

true if the backend was activated successfully or already active. false if there was an error

deactivate

public final boolean deactivate()

Description copied from interface: Backend

Deactivate the Backend. The backend should release any resources that were obtained as a direct result of a call to Backend.activate(). If the Backend is not active, this method should have no effect

This method is called by the framework when the Backend is deregistered.

Returns:

true if the backend was successfully deactivated or already inactive. false if the backend is still active.

isActive

public final boolean isActive()

Returns:

a boolean indicating whether the backend is currently active on this host