Module io.netty5.handler
Package io.netty5.handler.traffic

Class GlobalChannelTrafficShapingHandler

  • All Implemented Interfaces:
    ChannelHandler
    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(future -> ...) 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.

    • Constructor Detail

      • GlobalChannelTrafficShapingHandler

        public GlobalChannelTrafficShapingHandler​(EventExecutorGroup executor,
                                          long writeGlobalLimit,
                                          long readGlobalLimit,
                                          long writeChannelLimit,
                                          long readChannelLimit,
                                          long checkInterval,
                                          long maxTime)
        Create a new instance.
        Parameters:
        executor - the EventExecutorGroup 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​(EventExecutorGroup executor,
                                          long writeGlobalLimit,
                                          long readGlobalLimit,
                                          long writeChannelLimit,
                                          long readChannelLimit,
                                          long checkInterval)
        Create a new instance.
        Parameters:
        executor - the EventExecutorGroup 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​(EventExecutorGroup executor,
                                          long writeGlobalLimit,
                                          long readGlobalLimit,
                                          long writeChannelLimit,
                                          long readChannelLimit)
        Create a new instance.
        Parameters:
        executor - the EventExecutorGroup 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​(EventExecutorGroup executor,
                                          long checkInterval)
        Create a new instance.
        Parameters:
        executor - the EventExecutorGroup to use for the TrafficCounter.
        checkInterval - The delay between two computations of performances for channels or 0 if no stats are to be computed.

    • Method Detail

      • userDefinedWritabilityIndex

        protected int userDefinedWritabilityIndex()
        Overrides:
        userDefinedWritabilityIndex in class AbstractTrafficShapingHandler
        Returns:
        the index to be used by the TrafficShapingHandler to manage the user defined writability. For Channel TSH it is defined as 1, for Global TSH it is defined as 2, for GlobalChannel TSH it is defined as 3.

      • isSharable

        public boolean isSharable()
        Description copied from interface: ChannelHandler
        Returns true if this handler is sharable and thus can be added to more than one ChannelPipeline. By default, this method returns false. If this method returns false, you have to create a new handler instance every time you add it to a pipeline because it has unshared state such as member variables.

      • 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.

      • checkWaitReadTime

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

      • 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.