Package org.apache.pekko.routing

Class TailChoppingPool

java.lang.Object
org.apache.pekko.routing.TailChoppingPool
All Implemented Interfaces:
Serializable, Pool, PoolOverrideUnsetConfig<TailChoppingPool>, RouterConfig, scala.Equals, scala.Product
public final class TailChoppingPool extends Object implements Pool, PoolOverrideUnsetConfig<TailChoppingPool>, scala.Product, Serializable
A router pool with retry logic, intended for cases where a return message is expected in response to a message sent to the routee. As each message is sent to the routing pool, 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 pekko.actor.Status.Failure wrapping a pekko.pattern.AskTimeoutException is sent to the sender.

Refer to pekko.routing.TailChoppingRoutingLogic for comments regarding the goal of this routing algorithm.

The configuration parameter trumps the constructor arguments. This means that if you provide nrOfInstances during instantiation they will be ignored if the router is defined in the configuration file for the actor being used.

Supervision Setup

Any routees that are created by a router will be created as the router's children. The router is therefore also the children's supervisor.

The supervision strategy of the router actor can be configured with withSupervisorStrategy(org.apache.pekko.actor.SupervisorStrategy). If no strategy is provided, routers default to a strategy of &ldquo;always escalate&rdquo;. This means that errors are passed up to the router's supervisor for handling.

The router's supervisor will treat the error as an error with the router itself. Therefore a directive to stop or restart will cause the router itself to stop or restart. The router, in turn, will cause its children to stop and restart.

param: nrOfInstances initial number of routees in the pool

param: resizer optional resizer that dynamically adjust the pool size

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

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

param: supervisorStrategy strategy for supervising the routees, see 'Supervision Setup'

param: routerDispatcher dispatcher to use for the router head actor, which handles supervision, death watch and router management messages

See Also:

  • Constructor Details

    • TailChoppingPool

      public TailChoppingPool(int nrOfInstances, scala.Option<Resizer> resizer, scala.concurrent.duration.FiniteDuration within, scala.concurrent.duration.FiniteDuration interval, SupervisorStrategy supervisorStrategy, String routerDispatcher, boolean usePoolDispatcher)

    • TailChoppingPool

      public TailChoppingPool(com.typesafe.config.Config config)

    • TailChoppingPool

      public TailChoppingPool(int nr, scala.concurrent.duration.FiniteDuration within, scala.concurrent.duration.FiniteDuration interval)
      Java API
      Parameters:
      nr - initial number of routees in the pool
      within - expecting at least one reply within this duration, otherwise it will reply with pekko.pattern.AskTimeoutException in a pekko.actor.Status.Failure
      interval - duration after which next routee will be picked

    • TailChoppingPool

      public TailChoppingPool(int nr, Duration within, Duration interval)
      Java API
      Parameters:
      nr - initial number of routees in the pool
      within - expecting at least one reply within this duration, otherwise it will reply with pekko.pattern.AskTimeoutException in a pekko.actor.Status.Failure
      interval - duration after which next routee will be picked

  • Method Details

    • $lessinit$greater$default$2

      public static scala.Option<Resizer> $lessinit$greater$default$2()

    • $lessinit$greater$default$5

      public static SupervisorStrategy $lessinit$greater$default$5()

    • $lessinit$greater$default$6

      public static String $lessinit$greater$default$6()

    • $lessinit$greater$default$7

      public static boolean $lessinit$greater$default$7()

    • apply

      public static TailChoppingPool apply(int nrOfInstances, scala.Option<Resizer> resizer, scala.concurrent.duration.FiniteDuration within, scala.concurrent.duration.FiniteDuration interval, SupervisorStrategy supervisorStrategy, String routerDispatcher, boolean usePoolDispatcher)

    • apply$default$2

      public static scala.Option<Resizer> apply$default$2()

    • apply$default$5

      public static SupervisorStrategy apply$default$5()

    • apply$default$6

      public static String apply$default$6()

    • apply$default$7

      public static boolean apply$default$7()

    • unapply

      public static scala.Option<scala.Tuple7<Object,scala.Option<Resizer>,scala.concurrent.duration.FiniteDuration,scala.concurrent.duration.FiniteDuration,SupervisorStrategy,String,Object>> unapply(TailChoppingPool x$0)

    • nrOfInstances

      public int nrOfInstances()

    • resizer

      public scala.Option<Resizer> resizer()
      Description copied from interface: Pool
      Pool with dynamically resizable number of routees return the pekko.routing.Resizer to use. The resizer is invoked once when the router is created, before any messages can be sent to it. Resize is also triggered when messages are sent to the routees, and the resizer is invoked asynchronously, i.e. not necessarily before the message has been sent.
      Specified by:
      resizer in interface Pool

    • within

      public scala.concurrent.duration.FiniteDuration within()

    • interval

      public scala.concurrent.duration.FiniteDuration interval()

    • supervisorStrategy

      public SupervisorStrategy supervisorStrategy()
      Description copied from interface: Pool
      SupervisorStrategy for the head actor, i.e. for supervising the routees of the pool.
      Specified by:
      supervisorStrategy in interface Pool

    • routerDispatcher

      public String routerDispatcher()
      Description copied from interface: RouterConfig
      Dispatcher ID to use for running the &ldquo;head&rdquo; actor, which handles supervision, death watch and router management messages
      Specified by:
      routerDispatcher in interface RouterConfig

    • usePoolDispatcher

      public boolean usePoolDispatcher()
      Description copied from interface: Pool
      Use a dedicated dispatcher for the routees of the pool. The dispatcher is defined in 'pool-dispatcher' configuration property in the deployment section of the router.
      Specified by:
      usePoolDispatcher in interface Pool

    • createRouter

      public Router createRouter(ActorSystem system)
      Description copied from interface: RouterConfig
      Create the actual router, responsible for routing messages to routees.

      Specified by:
      createRouter in interface RouterConfig
      Parameters:
      system - the ActorSystem this router belongs to

    • nrOfInstances

      public int nrOfInstances(ActorSystem sys)
      Description copied from interface: Pool
      Initial number of routee instances
      Specified by:
      nrOfInstances in interface Pool

    • withSupervisorStrategy

      public TailChoppingPool withSupervisorStrategy(SupervisorStrategy strategy)
      Setting the supervisor strategy to be used for the &ldquo;head&rdquo; Router actor.
      Specified by:
      withSupervisorStrategy in interface PoolOverrideUnsetConfig<TailChoppingPool>

    • withResizer

      public TailChoppingPool withResizer(Resizer resizer)
      Setting the resizer to be used.
      Specified by:
      withResizer in interface PoolOverrideUnsetConfig<TailChoppingPool>

    • withDispatcher

      public TailChoppingPool withDispatcher(String dispatcherId)
      Setting the dispatcher to be used for the router head actor, which handles supervision, death watch and router management messages.

    • withFallback

      public RouterConfig withFallback(RouterConfig other)
      Uses the resizer and/or the supervisor strategy of the given RouterConfig if this RouterConfig doesn't have one, i.e. the resizer defined in code is used if resizer was not defined in config.
      Specified by:
      withFallback in interface RouterConfig

    • copy

      public TailChoppingPool copy(int nrOfInstances, scala.Option<Resizer> resizer, scala.concurrent.duration.FiniteDuration within, scala.concurrent.duration.FiniteDuration interval, SupervisorStrategy supervisorStrategy, String routerDispatcher, boolean usePoolDispatcher)

    • copy$default$1

      public int copy$default$1()

    • copy$default$2

      public scala.Option<Resizer> copy$default$2()

    • copy$default$3

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

    • copy$default$4

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

    • copy$default$5

      public SupervisorStrategy copy$default$5()

    • copy$default$6

      public String copy$default$6()

    • copy$default$7

      public boolean copy$default$7()

    • productPrefix

      public String productPrefix()
      Specified by:
      productPrefix in interface scala.Product

    • productArity

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

    • productElement

      public Object productElement(int x$1)
      Specified by:
      productElement in interface scala.Product

    • productIterator

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

    • canEqual

      public boolean canEqual(Object x$1)
      Specified by:
      canEqual in interface scala.Equals

    • productElementName

      public String productElementName(int x$1)
      Specified by:
      productElementName in interface scala.Product

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • equals

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