com.netflix.turbine.handler

Class HandlerQueueTuple<K extends TurbineData>

java.lang.Object

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

Type Parameters:

K -

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

Class that encapsulates that infrastructure needed by a TurbineDataHandler to receive data from multiple producers.

The HandlerQueueTuple object uses an EventQueue implementation to protect the publishers from a slow listener. It also employs a number of threads needed to poll repeatedly from the EventQueue and dispatch to the handler underneath. If the EventQueue is full then pushData(Collection) simply fails fast and moves on.

Note that the max queue size and the number of threads will help determine the throughput of a handler, and hence must be carefully chosen.

• When data is flowing at a roughly constant velocity then one can tune with a smaller queue assuming that there are sufficient no of threads.
• But when data is sparse and bursty, then we must select a larger queue size even if we use fewer threads.

Use Cases

The AggregateClusterMonitor employs this object to receive and aggregate data from multiple InstanceMonitor objects. The aggregator can in turn also dispatch data to TurbineDataHandler underneath using a HandlerQueueTuple for each handler as well, thus decoupling the performance of the aggregator from any potentially slow listener.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	HandlerQueueTuple.UnitTest

Constructor Summary

Constructors

Constructor and Description
HandlerQueueTuple(TurbineDataHandler<K> eventHandler)

Method Summary

Methods

Modifier and Type	Method and Description
TurbineDataHandler<K>	getHandler()
EventQueue<K>	getQueue()
boolean	previouslyStopped() Helper method to identify if the tuple has been requested to stop
void	pushData(java.util.Collection<K> statsData) Send data to the tuple
void	pushData(K data)
boolean	running() Helper to identify if the tuple is still running
void	start() Starts the poller threads and this causes the eventhandler to start receiving data via the TurbineDataHandler.handleData(Collection) method.
void	stop() Stops all the poller threads, and the event handler will stop receiving data.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

HandlerQueueTuple

public HandlerQueueTuple(TurbineDataHandler<K> eventHandler)

Parameters:

eventHandler -

Method Detail

start

public void start()
           throws java.lang.Exception

Starts the poller threads and this causes the eventhandler to start receiving data via the TurbineDataHandler.handleData(Collection) method.

Throws:

java.lang.Exception

stop

public void stop()

Stops all the poller threads, and the event handler will stop receiving data.

previouslyStopped

public boolean previouslyStopped()

Helper method to identify if the tuple has been requested to stop

Returns:

true/false

running

public boolean running()

Helper to identify if the tuple is still running

Returns:

true/false

getHandler

public TurbineDataHandler<K> getHandler()

Returns:

TurbineDataHandler

getQueue

public EventQueue<K> getQueue()

Returns:

EventQueue

pushData

public void pushData(java.util.Collection<K> statsData)

Send data to the tuple

Parameters:

statsData -

pushData

public void pushData(K data)

Parameters:

data -

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object