io.netty.handler.traffic

Class GlobalChannelTrafficShapingHandler

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.handler.traffic.AbstractTrafficShapingHandler

io.netty.handler.traffic.GlobalChannelTrafficShapingHandler

All Implemented Interfaces:

ChannelHandler

@ChannelHandler.Sharable
public class GlobalChannelTrafficShapingHandler
extends AbstractTrafficShapingHandler

This implementation of the AbstractTrafficShapingHandler is for global and per channel traffic shaping, that is to say a global limitation of the bandwidth, whatever the number of opened channels and a per channel limitation of the bandwidth.

This version shall not be in the same pipeline than other TrafficShapingHandler.

The general use should be as follow:

• Create your unique GlobalChannelTrafficShapingHandler like:
  
  GlobalChannelTrafficShapingHandler myHandler = new GlobalChannelTrafficShapingHandler(executor);
  
  The executor could be the underlying IO worker pool
  pipeline.addLast(myHandler);
  
  Note that this handler has a Pipeline Coverage of "all" which means only one such handler must be created and shared among all channels as the counter must be shared among all channels.
  
  Other arguments can be passed like write or read limitation (in bytes/s where 0 means no limitation) or the check interval (in millisecond) that represents the delay between two computations of the bandwidth and so the call back of the doAccounting method (0 means no accounting at all).
  Note that as this is a fusion of both Global and Channel Traffic Shaping, limits are in 2 sets, respectively Global and Channel.
  
  A value of 0 means no accounting for checkInterval. If you need traffic shaping but no such accounting, it is recommended to set a positive value, even if it is high since the precision of the Traffic Shaping depends on the period where the traffic is computed. The highest the interval, the less precise the traffic shaping will be. It is suggested as higher value something close to 5 or 10 minutes.
  
  maxTimeToWait, by default set to 15s, allows to specify an upper bound of time shaping.
  
  
• In your handler, you should consider to use the channel.isWritable() and channelWritabilityChanged(ctx) to handle writability, or through future.addListener(new GenericFutureListener()) on the future returned by ctx.write().
• You shall also consider to have object size in read or write operations relatively adapted to the bandwidth you required: for instance having 10 MB objects for 10KB/s will lead to burst effect, while having 100 KB objects for 1 MB/s should be smoothly handle by this TrafficShaping handler.
  
  
• Some configuration methods will be taken as best effort, meaning that all already scheduled traffics will not be changed, but only applied to new traffics.
  So the expected usage of those methods are to be used not too often, accordingly to the traffic shaping configuration.

Be sure to call release() once this handler is not needed anymore to release all internal resources. This will not shutdown the EventExecutor as it may be shared, so you need to do this by your own.

Nested Class Summary

Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

ChannelHandler.Sharable, ChannelHandler.Skip

Field Summary

Fields inherited from class io.netty.handler.traffic.AbstractTrafficShapingHandler

checkInterval, DEFAULT_CHECK_INTERVAL, DEFAULT_MAX_TIME, maxTime, trafficCounter

Constructor Summary

Constructors

Constructor and Description
GlobalChannelTrafficShapingHandler(ScheduledExecutorService executor) Create a new instance.
GlobalChannelTrafficShapingHandler(ScheduledExecutorService executor, long checkInterval) Create a new instance.
GlobalChannelTrafficShapingHandler(ScheduledExecutorService executor, long writeGlobalLimit, long readGlobalLimit, long writeChannelLimit, long readChannelLimit) Create a new instance.
GlobalChannelTrafficShapingHandler(ScheduledExecutorService executor, long writeGlobalLimit, long readGlobalLimit, long writeChannelLimit, long readChannelLimit, long checkInterval) Create a new instance.
GlobalChannelTrafficShapingHandler(ScheduledExecutorService executor, long writeGlobalLimit, long readGlobalLimit, long writeChannelLimit, long readChannelLimit, long checkInterval, long maxTime) Create a new instance.

Method Summary

Methods

Modifier and Type	Method and Description
float	accelerationFactor()
void	channelRead(ChannelHandlerContext ctx, Object msg) Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelHandler in the ChannelPipeline.
Collection<TrafficCounter>	channelTrafficCounters() To allow for instance doAccounting to use the TrafficCounter per channel.
protected long	checkWaitReadTime(ChannelHandlerContext ctx, long wait, long now) Method overridden in GTSH to take into account specific timer for the channel.
void	configureChannel(long newWriteLimit, long newReadLimit)
protected void	doAccounting(TrafficCounter counter) Called each time the accounting is computed from the TrafficCounters.
long	getMaxGlobalWriteSize()
long	getReadChannelLimit()
long	getWriteChannelLimit()
void	handlerAdded(ChannelHandlerContext ctx) Do nothing by default, sub-classes may override this method.
void	handlerRemoved(ChannelHandlerContext ctx) Do nothing by default, sub-classes may override this method.
protected void	informReadOperation(ChannelHandlerContext ctx, long now) Method overridden in GTSH to take into account specific timer for the channel.
float	maxDeviation()
protected long	maximumCumulativeReadBytes()
protected long	maximumCumulativeWrittenBytes()
long	queuesSize()
void	release() Release all internal resources of this instance.
void	setMaxDeviation(float maxDeviation, float slowDownFactor, float accelerationFactor)
void	setMaxGlobalWriteSize(long maxGlobalWriteSize) Note the change will be taken as best effort, meaning that all already scheduled traffics will not be changed, but only applied to new traffics.
void	setReadChannelLimit(long readLimit)
void	setWriteChannelLimit(long writeLimit)
float	slowDownFactor()
protected void	submitWrite(ChannelHandlerContext ctx, Object msg, long size, long writedelay, long now, ChannelPromise promise)
String	toString()
void	write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) Calls ChannelHandlerContext.write(Object) to forward to the next ChannelHandler in the ChannelPipeline.

Methods inherited from class io.netty.handler.traffic.AbstractTrafficShapingHandler

calculateSize, channelRegistered, configure, configure, configure, getCheckInterval, getMaxTimeWait, getMaxWriteDelay, getMaxWriteSize, getReadLimit, getWriteLimit, isHandlerActive, read, setCheckInterval, setMaxTimeWait, setMaxWriteDelay, setMaxWriteSize, setReadLimit, setWriteLimit, submitWrite, trafficCounter

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

bind, channelActive, channelInactive, channelReadComplete, channelUnregistered, channelWritabilityChanged, close, connect, deregister, disconnect, exceptionCaught, flush, isSharable, userEventTriggered

Methods inherited from class java.lang.Object

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

Constructor Detail

GlobalChannelTrafficShapingHandler

public GlobalChannelTrafficShapingHandler(ScheduledExecutorService executor,
                                  long writeGlobalLimit,
                                  long readGlobalLimit,
                                  long writeChannelLimit,
                                  long readChannelLimit,
                                  long checkInterval,
                                  long maxTime)

Create a new instance.

Parameters:

executor - the ScheduledExecutorService to use for the TrafficCounter.

writeGlobalLimit - 0 or a limit in bytes/s

readGlobalLimit - 0 or a limit in bytes/s

writeChannelLimit - 0 or a limit in bytes/s

readChannelLimit - 0 or a limit in bytes/s

checkInterval - The delay between two computations of performances for channels or 0 if no stats are to be computed.

maxTime - The maximum delay to wait in case of traffic excess.

GlobalChannelTrafficShapingHandler

public GlobalChannelTrafficShapingHandler(ScheduledExecutorService executor,
                                  long writeGlobalLimit,
                                  long readGlobalLimit,
                                  long writeChannelLimit,
                                  long readChannelLimit,
                                  long checkInterval)

Create a new instance.

Parameters:

executor - the ScheduledExecutorService to use for the TrafficCounter.

writeGlobalLimit - 0 or a limit in bytes/s

readGlobalLimit - 0 or a limit in bytes/s

writeChannelLimit - 0 or a limit in bytes/s

readChannelLimit - 0 or a limit in bytes/s

checkInterval - The delay between two computations of performances for channels or 0 if no stats are to be computed.

GlobalChannelTrafficShapingHandler

public GlobalChannelTrafficShapingHandler(ScheduledExecutorService executor,
                                  long writeGlobalLimit,
                                  long readGlobalLimit,
                                  long writeChannelLimit,
                                  long readChannelLimit)

Create a new instance.

Parameters:

executor - the ScheduledExecutorService to use for the TrafficCounter.

writeGlobalLimit - 0 or a limit in bytes/s

readGlobalLimit - 0 or a limit in bytes/s

writeChannelLimit - 0 or a limit in bytes/s

readChannelLimit - 0 or a limit in bytes/s

GlobalChannelTrafficShapingHandler

public GlobalChannelTrafficShapingHandler(ScheduledExecutorService executor,
                                  long checkInterval)

Create a new instance.

Parameters:

executor - the ScheduledExecutorService to use for the TrafficCounter.

checkInterval - The delay between two computations of performances for channels or 0 if no stats are to be computed.

GlobalChannelTrafficShapingHandler

public GlobalChannelTrafficShapingHandler(ScheduledExecutorService executor)

Create a new instance.

Parameters:

executor - the ScheduledExecutorService to use for the TrafficCounter.

Method Detail

maxDeviation

public float maxDeviation()

Returns:

the current max deviation

accelerationFactor

public float accelerationFactor()

Returns:

the current acceleration factor

slowDownFactor

public float slowDownFactor()

Returns:

the current slow down factor

setMaxDeviation

public void setMaxDeviation(float maxDeviation,
                   float slowDownFactor,
                   float accelerationFactor)

Parameters:

maxDeviation - the maximum deviation to allow during computation of average, default deviation being 0.1, so +/-10% of the desired bandwidth. Maximum being 0.4.

slowDownFactor - the factor set as +x% to the too fast client (minimal value being 0, meaning no slow down factor), default being 40% (0.4).

accelerationFactor - the factor set as -x% to the too slow client (maximal value being 0, meaning no acceleration factor), default being -10% (-0.1).

doAccounting

protected void doAccounting(TrafficCounter counter)

Description copied from class: AbstractTrafficShapingHandler

Called each time the accounting is computed from the TrafficCounters. This method could be used for instance to implement almost real time accounting.

Overrides:

doAccounting in class AbstractTrafficShapingHandler

Parameters:

counter - the TrafficCounter that computes its performance

getMaxGlobalWriteSize

public long getMaxGlobalWriteSize()

Returns:

the maxGlobalWriteSize

setMaxGlobalWriteSize

public void setMaxGlobalWriteSize(long maxGlobalWriteSize)

Note the change will be taken as best effort, meaning that all already scheduled traffics will not be changed, but only applied to new traffics.
So the expected usage of this method is to be used not too often, accordingly to the traffic shaping configuration.

Parameters:

maxGlobalWriteSize - the maximum Global Write Size allowed in the buffer globally for all channels before write suspended is set.

queuesSize

public long queuesSize()

Returns:

the global size of the buffers for all queues.

configureChannel

public void configureChannel(long newWriteLimit,
                    long newReadLimit)

Parameters:

newWriteLimit - Channel write limit

newReadLimit - Channel read limit

getWriteChannelLimit

public long getWriteChannelLimit()

Returns:

Channel write limit

setWriteChannelLimit

public void setWriteChannelLimit(long writeLimit)

Parameters:

writeLimit - Channel write limit

getReadChannelLimit

public long getReadChannelLimit()

Returns:

Channel read limit

setReadChannelLimit

public void setReadChannelLimit(long readLimit)

Parameters:

readLimit - Channel read limit

release

public final void release()

Release all internal resources of this instance.

handlerAdded

public void handlerAdded(ChannelHandlerContext ctx)
                  throws Exception

Description copied from class: ChannelHandlerAdapter

Do nothing by default, sub-classes may override this method.

Specified by:

handlerAdded in interface ChannelHandler

Overrides:

handlerAdded in class ChannelHandlerAdapter

Throws:

Exception

handlerRemoved

public void handlerRemoved(ChannelHandlerContext ctx)
                    throws Exception

Description copied from class: ChannelHandlerAdapter

Do nothing by default, sub-classes may override this method.

Specified by:

handlerRemoved in interface ChannelHandler

Overrides:

handlerRemoved in class ChannelHandlerAdapter

Throws:

Exception

channelRead

public void channelRead(ChannelHandlerContext ctx,
               Object msg)
                 throws Exception

Description copied from class: ChannelHandlerAdapter

Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

Specified by:

channelRead in interface ChannelHandler

Overrides:

channelRead in class AbstractTrafficShapingHandler

Throws:

Exception

checkWaitReadTime

protected long checkWaitReadTime(ChannelHandlerContext ctx,
                     long wait,
                     long now)

Description copied from class: AbstractTrafficShapingHandler

Method overridden in GTSH to take into account specific timer for the channel.

wait - the wait delay computed in ms

now - the relative now time in ms

Returns:

the wait to use according to the context

informReadOperation

protected void informReadOperation(ChannelHandlerContext ctx,
                       long now)

Description copied from class: AbstractTrafficShapingHandler

Method overridden in GTSH to take into account specific timer for the channel.

now - the relative now time in ms

maximumCumulativeWrittenBytes

protected long maximumCumulativeWrittenBytes()

maximumCumulativeReadBytes

protected long maximumCumulativeReadBytes()

channelTrafficCounters

public Collection<TrafficCounter> channelTrafficCounters()

To allow for instance doAccounting to use the TrafficCounter per channel.

Returns:

the list of TrafficCounters that exists at the time of the call.

write

public void write(ChannelHandlerContext ctx,
         Object msg,
         ChannelPromise promise)
           throws Exception

Description copied from class: ChannelHandlerAdapter

Calls ChannelHandlerContext.write(Object) to forward to the next ChannelHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

Specified by:

write in interface ChannelHandler

Overrides:

write in class AbstractTrafficShapingHandler

Parameters:

ctx - the ChannelHandlerContext for which the write operation is made

msg - the message to write

promise - the ChannelPromise to notify once the operation completes

Throws:

Exception - thrown if an error accour

submitWrite

protected void submitWrite(ChannelHandlerContext ctx,
               Object msg,
               long size,
               long writedelay,
               long now,
               ChannelPromise promise)

toString

public String toString()

Overrides:

toString in class AbstractTrafficShapingHandler