Class GlobalTrafficShapingHandler

java.lang.Object
io.netty.channel.ChannelHandlerAdapter
io.netty.channel.ChannelInboundHandlerAdapter
io.netty.channel.ChannelDuplexHandler
io.netty.handler.traffic.AbstractTrafficShapingHandler
io.netty.handler.traffic.GlobalTrafficShapingHandler
All Implemented Interfaces:
ChannelHandler, ChannelInboundHandler, ChannelOutboundHandler
@Sharable 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(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.

  • Field Details

    • channelQueues

      private final ConcurrentMap<Integer, GlobalTrafficShapingHandler.PerChannel> channelQueues
      All queues per channel

    • queuesSize

      private final AtomicLong queuesSize
      Global queues size

    • maxGlobalWriteSize

      long maxGlobalWriteSize
      Max size in the list before proposing to stop writing new objects from next handlers for all channel (global)

  • Constructor Details

    • GlobalTrafficShapingHandler

      public GlobalTrafficShapingHandler(ScheduledExecutorService executor, long writeLimit, long readLimit, long checkInterval, long maxTime)
      Create a new instance.
      Parameters:
      executor - the ScheduledExecutorService 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(ScheduledExecutorService 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 ScheduledExecutorService 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(ScheduledExecutorService 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 ScheduledExecutorService to use for the TrafficCounter.
      writeLimit - 0 or a limit in bytes/s
      readLimit - 0 or a limit in bytes/s

    • GlobalTrafficShapingHandler

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

    • 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 Details