com.netflix.turbine.handler

Class TurbineDataDispatcher<K extends TurbineData>

java.lang.Object

com.netflix.turbine.handler.TurbineDataDispatcher<K>

Type Parameters:

K -

public class TurbineDataDispatcher<K extends TurbineData>
extends java.lang.Object

Class the manages the mapping from InstanceMonitor connections to TurbineDataHandler listeners.

When registering a TurbineDataHandler with the dispatcher, one must specify the Instance or host that the handler is interested in receiving data from.

The dispatcher maintains a HandlerQueueTuple object for each registered handler and hence all handlers can receive data from multiple InstanceMonitor objects.

This is how the ClusterMonitor object actually works. For each Instance that it needs to monitor, it opens a connection to that host using an InstanceMonitor and then stores that object in a MonitorConsole for later use and discovery. The ClusterMonitor then also registers it's {TurbineDataHandler as a listener to that host in the dispatcher so that it can receive events. This way a single handler can be registered for multiple host monitors.

Note that another use of the dispatcher is the opposite case where multiple listeners can express interest in data from the same host. In this case we can have multiple TurbineDataHandler objects registered to the same InstanceMonitor via the dispatcher.

See Also:

InstanceMonitor

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TurbineDataDispatcher.UnitTest

Constructor Summary

Constructors

Constructor and Description
TurbineDataDispatcher(java.lang.String name) Public constructor

Method Summary

Methods

Modifier and Type	Method and Description
void	deregisterEventHandler(java.lang.String handlerName) De register an event listener
void	deregisterEventHandler(TurbineDataHandler<K> handler) Deregister an event listener
TurbineDataHandler<K>	findHandlerForHost(Instance host, java.lang.String handlerName) Helper method to check if a handler is registered for a host.
java.util.Set<java.lang.String>	getAllHandlerNames() Helpful method used to print out all the handler names.
java.lang.String	getName()
void	handleHostLost(Instance host) This is meant to be called when a monitor is shutting down.
void	pushData(java.util.Collection<java.lang.String> handlers, java.util.Collection<K> statsData) Method that pushes data to a collection of handlers directly
void	pushData(java.util.Collection<java.lang.String> handlers, K statsData)
boolean	pushData(Instance host, java.util.Collection<K> statsData) Common loop life-cycle logic.
boolean	pushData(Instance host, K statsData)
void	registerEventHandler(Instance host, TurbineDataHandler<K> handler) Register event listener to this host
boolean	running()
void	stopDispatcher() Stop the dispatcher.

Methods inherited from class java.lang.Object

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

Constructor Detail

TurbineDataDispatcher

public TurbineDataDispatcher(java.lang.String name)

Public constructor

Method Detail

getName

public java.lang.String getName()

handleHostLost

public void handleHostLost(Instance host)

This is meant to be called when a monitor is shutting down.

Parameters:

host -

registerEventHandler

public void registerEventHandler(Instance host,
                        TurbineDataHandler<K> handler)

Register event listener to this host

Parameters:

host -

handler -

deregisterEventHandler

public void deregisterEventHandler(java.lang.String handlerName)

De register an event listener

Parameters:

handlerName -

deregisterEventHandler

public void deregisterEventHandler(TurbineDataHandler<K> handler)

Deregister an event listener

Parameters:

handler -

findHandlerForHost

public TurbineDataHandler<K> findHandlerForHost(Instance host,
                                       java.lang.String handlerName)

Helper method to check if a handler is registered for a host. This can help callers effectively manage their event handlers

Parameters:

host -

handlerName -

Returns:

StatsEventHandler

pushData

public boolean pushData(Instance host,
               java.util.Collection<K> statsData)

Common loop life-cycle logic.

This will asynchronously invoke handleData on all listeners. We do it asynchronously because we can potentially have quite a few handlers and some of them with delays which we don't want to have impact all other handlers.

Parameters:

host -

statsData -

Returns:

boolean: true/false indicating whether there are any listeners left

Throws:

java.lang.InterruptedException

pushData

public boolean pushData(Instance host,
               K statsData)

pushData

public void pushData(java.util.Collection<java.lang.String> handlers,
            java.util.Collection<K> statsData)

Method that pushes data to a collection of handlers directly

Parameters:

handlers -

statsData -

pushData

public void pushData(java.util.Collection<java.lang.String> handlers,
            K statsData)

stopDispatcher

public void stopDispatcher()

Stop the dispatcher. Shutdown everything This notifies everyone downstream that all hosts are lost (a hacky mechanism to cause all event handlers to eject) It also sets the stopped status which will notify monitors as they try to send data

running

public boolean running()

getAllHandlerNames

public java.util.Set<java.lang.String> getAllHandlerNames()

Helpful method used to print out all the handler names. Used for jmx stats

Returns:

Set