Package akka.routing

Class TailChoppingRoutingLogic

  • All Implemented Interfaces:
    NoSerializationVerificationNeeded, RoutingLogic,, scala.Equals, scala.Product

    public final class TailChoppingRoutingLogic
    extends java.lang.Object
    implements RoutingLogic, scala.Product,
    As each message is sent to the router, the routees are randomly ordered. The message is sent to the first routee. If no response is received before the interval has passed, the same message is sent to the next routee. This process repeats until either a response is received from some routee, the routees in the pool are exhausted, or the within duration has passed since the first send. If no routee sends a response in time, a Status.Failure wrapping a AskTimeoutException is sent to the sender.

    The goal of this routing algorithm is to decrease tail latencies ("chop off the tail latency") in situations where multiple routees can perform the same piece of work, and where a routee may occasionally respond more slowly than expected. In this case, sending the same work request (also known as a "backup request") to another actor results in decreased response time - because it's less probable that multiple actors are under heavy load simultaneously. This technique is explained in depth in Jeff Dean's presentation on Achieving Rapid Response Times in Large Online Services.

    param: scheduler schedules sending messages to routees

    param: within expecting at least one reply within this duration, otherwise it will reply with AskTimeoutException in a Status.Failure

    param: interval duration after which the message will be sent to the next routee

    param: context execution context used by scheduler

    See Also:
    Serialized Form
    • Constructor Detail

      • TailChoppingRoutingLogic

        public TailChoppingRoutingLogic​(Scheduler scheduler,
                                        scala.concurrent.duration.FiniteDuration within,
                                        scala.concurrent.duration.FiniteDuration interval,
                                        scala.concurrent.ExecutionContext context)
    • Method Detail

      • apply

        public static TailChoppingRoutingLogic apply​(Scheduler scheduler,
                                                     scala.concurrent.duration.FiniteDuration within,
                                                     scala.concurrent.duration.FiniteDuration interval,
                                                     scala.concurrent.ExecutionContext context)
      • unapply

        public static scala.Option<scala.Tuple4<Scheduler,​scala.concurrent.duration.FiniteDuration,​scala.concurrent.duration.FiniteDuration,​scala.concurrent.ExecutionContext>> unapply​(TailChoppingRoutingLogic x$0)
      • within

        public scala.concurrent.duration.FiniteDuration within()
      • interval

        public scala.concurrent.duration.FiniteDuration interval()
      • context

        public scala.concurrent.ExecutionContext context()
      • select

        public Routee select​(java.lang.Object message,
                             scala.collection.immutable.IndexedSeq<Routee> routees)
        Description copied from interface: RoutingLogic
        Pick the destination for a given message. Normally it picks one of the passed routees, but in the end it is up to the implementation to return whatever Routee to use for sending a specific message.

        When implemented from Java it can be good to know that routees.apply(index) can be used to get an element from the IndexedSeq.

        Specified by:
        select in interface RoutingLogic
      • copy

        public TailChoppingRoutingLogic copy​(Scheduler scheduler,
                                             scala.concurrent.duration.FiniteDuration within,
                                             scala.concurrent.duration.FiniteDuration interval,
                                             scala.concurrent.ExecutionContext context)
      • copy$default$1

        public Scheduler copy$default$1()
      • copy$default$2

        public scala.concurrent.duration.FiniteDuration copy$default$2()
      • copy$default$3

        public scala.concurrent.duration.FiniteDuration copy$default$3()
      • copy$default$4

        public scala.concurrent.ExecutionContext copy$default$4()
      • productPrefix

        public java.lang.String productPrefix()
        Specified by:
        productPrefix in interface scala.Product
      • productArity

        public int productArity()
        Specified by:
        productArity in interface scala.Product
      • productElement

        public java.lang.Object productElement​(int x$1)
        Specified by:
        productElement in interface scala.Product
      • productIterator

        public scala.collection.Iterator<java.lang.Object> productIterator()
        Specified by:
        productIterator in interface scala.Product
      • canEqual

        public boolean canEqual​(java.lang.Object x$1)
        Specified by:
        canEqual in interface scala.Equals
      • productElementName

        public java.lang.String productElementName​(int x$1)
        Specified by:
        productElementName in interface scala.Product
      • hashCode

        public int hashCode()
        hashCode in class java.lang.Object
      • toString

        public java.lang.String toString()
        toString in class java.lang.Object
      • equals

        public boolean equals​(java.lang.Object x$1)
        Specified by:
        equals in interface scala.Equals
        equals in class java.lang.Object