Package org.apache.pekko.actor.typed.scaladsl

Interface PoolRouter<T>

public interface PoolRouter<T>
Provides builder style configuration options for pool routers

Not for user extension. Use Routers.pool(int, org.apache.pekko.actor.typed.Behavior<T>) to create

  • Method Details

    • withBroadcastPredicate

      PoolRouter<T> withBroadcastPredicate(scala.Function1<T,Object> predicate)
      Any message that the predicate returns true for will be broadcast to all routees.

    • withConsistentHashingRouting

      PoolRouter<T> withConsistentHashingRouting(int virtualNodesFactor, scala.Function1<T,String> mapping)
      Route messages by using consistent hashing.

      From wikipedia: Consistent hashing is based on mapping each object to a point on a circle (or equivalently, mapping each object to a real angle). The system maps each available machine (or other storage bucket) to many pseudo-randomly distributed points on the same circle.

      Parameters:
      virtualNodesFactor - This factor has to be greater or equal to 1. Assuming that the reader knows what consistent hashing is (if not, please refer: https://www.tom-e-white.com/2007/11/consistent-hashing.html or wiki). This number is responsible for creating additional, virtual addresses for a provided set of routees, so that in the total number of points on hashing ring will be equal to numberOfRoutees * virtualNodesFactor (if virtualNodesFactor is equal to 1, then no additional points will be created).

      Those virtual nodes are being created by additionally rehashing routees to evenly distribute them across hashing ring. Consider increasing this number when you have a small number of routees. For bigger loads one can aim in having around 100-200 total addresses.

      mapping - Hash key extractor. This function will be used in consistent hashing process. Result of this operation should possibly uniquely distinguish messages.

    • withPoolSize

      PoolRouter<T> withPoolSize(int poolSize)
      Set a new pool size from the one set at construction

    • withRandomRouting

      PoolRouter<T> withRandomRouting()
      Route messages by randomly selecting the routee from the available routees.

      Random routing makes it less likely that every poolSize message from a single producer ends up in the same mailbox of a slow actor.

    • withRoundRobinRouting

      PoolRouter<T> withRoundRobinRouting()
      Route messages through round robin, providing a fair distribution of messages across the routees.

      Round robin gives fair routing where every available routee gets the same amount of messages

      This is the default for pool routers.

    • withRouteeProps

      PoolRouter<T> withRouteeProps(Props routeeProps)
      Set the props used to spawn the pool's routees