Package org.apache.pekko.cluster.metrics

Class AdaptiveLoadBalancingPool

java.lang.Object
org.apache.pekko.cluster.metrics.AdaptiveLoadBalancingPool
All Implemented Interfaces:
Serializable, Pool, RouterConfig, scala.Equals, scala.Product
public final class AdaptiveLoadBalancingPool extends Object implements Pool, scala.Product, Serializable
A router pool that performs load balancing of messages to cluster nodes based on cluster metric data.

It uses random selection of routees based on probabilities derived from the remaining capacity of corresponding node.

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 “always escalate”. 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: metricsSelector decides what probability to use for selecting a routee, based on remaining capacity as indicated by the node metrics

param: nrOfInstances initial number of routees in the pool

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

    • AdaptiveLoadBalancingPool

      public AdaptiveLoadBalancingPool(MetricsSelector metricsSelector, int nrOfInstances, SupervisorStrategy supervisorStrategy, String routerDispatcher, boolean usePoolDispatcher)

    • AdaptiveLoadBalancingPool

      public AdaptiveLoadBalancingPool(com.typesafe.config.Config config, DynamicAccess dynamicAccess)

    • AdaptiveLoadBalancingPool

      public AdaptiveLoadBalancingPool(MetricsSelector metricsSelector, int nr)
      Java API
      Parameters:
      metricsSelector - decides what probability to use for selecting a routee, based on remaining capacity as indicated by the node metrics
      nr - initial number of routees in the pool

  • Method Details

    • $lessinit$greater$default$1

      public static MetricsSelector $lessinit$greater$default$1()

    • $lessinit$greater$default$2

      public static int $lessinit$greater$default$2()

    • $lessinit$greater$default$3

      public static SupervisorStrategy $lessinit$greater$default$3()

    • $lessinit$greater$default$4

      public static String $lessinit$greater$default$4()

    • $lessinit$greater$default$5

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

    • apply

      public static AdaptiveLoadBalancingPool apply(MetricsSelector metricsSelector, int nrOfInstances, SupervisorStrategy supervisorStrategy, String routerDispatcher, boolean usePoolDispatcher)

    • apply$default$1

      public static MetricsSelector apply$default$1()

    • apply$default$2

      public static int apply$default$2()

    • apply$default$3

      public static SupervisorStrategy apply$default$3()

    • apply$default$4

      public static String apply$default$4()

    • apply$default$5

      public static boolean apply$default$5()

    • unapply

      public static scala.Option<scala.Tuple5<MetricsSelector,Object,SupervisorStrategy,String,Object>> unapply(AdaptiveLoadBalancingPool x$0)

    • metricsSelector

      public MetricsSelector metricsSelector()

    • nrOfInstances

      public int nrOfInstances()

    • 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

    • 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

    • nrOfInstances

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

    • routingLogicController

      public scala.Option<Props> routingLogicController(RoutingLogic routingLogic)
      Description copied from interface: RouterConfig
      Possibility to define an actor for controlling the routing logic from external stimuli (e.g. monitoring metrics). This actor will be a child of the router "head" actor. Management messages not handled by the "head" actor are delegated to this controller actor.
      Specified by:
      routingLogicController in interface RouterConfig

    • withSupervisorStrategy

      public AdaptiveLoadBalancingPool withSupervisorStrategy(SupervisorStrategy strategy)
      Setting the supervisor strategy to be used for the &ldquo;head&rdquo; Router actor.

    • withDispatcher

      public AdaptiveLoadBalancingPool 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 supervisor strategy of the given RouterConfig if this RouterConfig doesn't have one
      Specified by:
      withFallback in interface RouterConfig

    • copy

      public AdaptiveLoadBalancingPool copy(MetricsSelector metricsSelector, int nrOfInstances, SupervisorStrategy supervisorStrategy, String routerDispatcher, boolean usePoolDispatcher)

    • copy$default$1

      public MetricsSelector copy$default$1()

    • copy$default$2

      public int copy$default$2()

    • copy$default$3

      public SupervisorStrategy copy$default$3()

    • copy$default$4

      public String copy$default$4()

    • copy$default$5

      public boolean copy$default$5()

    • 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