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

Class GlobalTrafficShapingHandler

  • All Implemented Interfaces:
    ChannelHandler
    public class GlobalTrafficShapingHandler
extends AbstractTrafficShapingHandler

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

    Note the index used in OutboundBuffer.setUserDefinedWritability(index, boolean) is 2.

    The general use should be as follow:

    • Create your unique GlobalTrafficShapingHandler like:

      GlobalTrafficShapingHandler myHandler = new GlobalTrafficShapingHandler(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).

      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

      • GlobalTrafficShapingHandler

        public GlobalTrafficShapingHandler​(EventExecutorGroup executor,
                                   long writeLimit,
                                   long readLimit,
                                   long checkInterval,
                                   long maxTime)
        Create a new instance.
        Parameters:
        executor - the EventExecutorGroup to use for the TrafficCounter.
        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.

      • GlobalTrafficShapingHandler

        public GlobalTrafficShapingHandler​(EventExecutorGroup executor,
                                   long writeLimit,
                                   long readLimit,
                                   long checkInterval)
        Create a new instance using default max time as delay allowed value of 15000 ms.
        Parameters:
        executor - the EventExecutorGroup to use for the TrafficCounter.
        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.

      • GlobalTrafficShapingHandler

        public GlobalTrafficShapingHandler​(EventExecutorGroup executor,
                                   long writeLimit,
                                   long readLimit)
        Create a new instance using default Check Interval value of 1000 ms and default max time as delay allowed value of 15000 ms.
        Parameters:
        executor - the EventExecutorGroup to use for the TrafficCounter.
        writeLimit - 0 or a limit in bytes/s
        readLimit - 0 or a limit in bytes/s

      • GlobalTrafficShapingHandler

        public GlobalTrafficShapingHandler​(EventExecutorGroup executor,
                                   long checkInterval)
        Create a new instance using default max time as delay allowed value of 15000 ms and no limit.
        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.

      • GlobalTrafficShapingHandler

        public GlobalTrafficShapingHandler​(EventExecutor executor)
        Create a new instance using default Check Interval value of 1000 ms and default max time as delay allowed value of 15000 ms and no limit.
        Parameters:
        executor - the EventExecutor to use for the TrafficCounter.

    • Method Detail

      • 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.

      • 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.

      • getMaxGlobalWriteSize

        public long getMaxGlobalWriteSize()
        Returns:
        the maxGlobalWriteSize default value being 400 MB.

      • 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, default value being 400 MB.

      • queuesSize

        public long queuesSize()
        Returns:
        the global size of the buffers for all queues.

      • release

        public final void release()
        Release all internal resources of this instance.