io.netty.handler.traffic

Class ChannelTrafficShapingHandler

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.channel.ChannelDuplexHandler

io.netty.handler.traffic.AbstractTrafficShapingHandler

io.netty.handler.traffic.ChannelTrafficShapingHandler

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler, ChannelOutboundHandler

public class ChannelTrafficShapingHandler
extends AbstractTrafficShapingHandler

This implementation of the AbstractTrafficShapingHandler is for channel traffic shaping, that is to say a per channel limitation of the bandwidth.

Note the index used in OutboundBuffer.setUserDefinedWritability(index, boolean) is 1.

The general use should be as follow:

• Add in your pipeline a new ChannelTrafficShapingHandler.

  ChannelTrafficShapingHandler myHandler = new ChannelTrafficShapingHandler();

  pipeline.addLast(myHandler);

  Note that this handler has a Pipeline Coverage of "one" which means a new handler must be created for each new channel as the counter cannot 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).

  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.

Nested Class Summary

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

ChannelHandler.Sharable

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
ChannelTrafficShapingHandler(long checkInterval) Create a new instance using default max time as delay allowed value of 15000 ms and no limit.
ChannelTrafficShapingHandler(long writeLimit, long readLimit) Create a new instance using default Check Interval value of 1000 ms and max time as delay allowed value of 15000 ms.
ChannelTrafficShapingHandler(long writeLimit, long readLimit, long checkInterval) Create a new instance using default max time as delay allowed value of 15000 ms.
ChannelTrafficShapingHandler(long writeLimit, long readLimit, long checkInterval, long maxTime) Create a new instance.

Method Summary

Modifier and Type	Method and Description
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.
long	queueSize()

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

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

Methods inherited from class io.netty.channel.ChannelDuplexHandler

bind, close, connect, deregister, disconnect, flush

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelInactive, channelReadComplete, channelUnregistered, channelWritabilityChanged, exceptionCaught, userEventTriggered

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, isSharable

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.netty.channel.ChannelHandler

exceptionCaught

Constructor Detail

ChannelTrafficShapingHandler

public ChannelTrafficShapingHandler(long writeLimit,
                                    long readLimit,
                                    long checkInterval,
                                    long maxTime)

Create a new instance.

Parameters:

writeLimit - 0 or a limit in bytes/s

readLimit - 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.

ChannelTrafficShapingHandler

public ChannelTrafficShapingHandler(long writeLimit,
                                    long readLimit,
                                    long checkInterval)

Create a new instance using default max time as delay allowed value of 15000 ms.

Parameters:

writeLimit - 0 or a limit in bytes/s

readLimit - 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.

ChannelTrafficShapingHandler

public ChannelTrafficShapingHandler(long writeLimit,
                                    long readLimit)

Create a new instance using default Check Interval value of 1000 ms and max time as delay allowed value of 15000 ms.

Parameters:

writeLimit - 0 or a limit in bytes/s

readLimit - 0 or a limit in bytes/s

ChannelTrafficShapingHandler

public ChannelTrafficShapingHandler(long checkInterval)

Create a new instance using default max time as delay allowed value of 15000 ms and no limit.

Parameters:

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

Method Detail

handlerAdded

public void handlerAdded(ChannelHandlerContext ctx)
                  throws java.lang.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:

java.lang.Exception

handlerRemoved

public void handlerRemoved(ChannelHandlerContext ctx)
                    throws java.lang.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:

java.lang.Exception

queueSize

public long queueSize()

Returns:

current size in bytes of the write buffer.