Enum Edge.RoutingPolicy

All Implemented Interfaces:
Serializable, Comparable<Edge.RoutingPolicy>, java.lang.constant.Constable
Enclosing class:

public static enum Edge.RoutingPolicy
extends Enum<Edge.RoutingPolicy>
implements Serializable
An edge describes a connection from many upstream processors to many downstream processors. The routing policy decides where exactly to route each particular item emitted from an upstream processor. To simplify the reasoning we introduce the concept of the set of candidate downstream processors, or the candidate set for short. On a local edge the candidate set contains only local processors and on a distributed edge it contain all the processors.
  • Enum Constant Details


      public static final Edge.RoutingPolicy UNICAST
      For each item a single destination processor is chosen from the candidate set, with no restriction on the choice.

      public static final Edge.RoutingPolicy ISOLATED
      Like UNICAST, but guarantees that any given downstream processor receives data from exactly one upstream processor. This is needed in some DAG setups to apply selective backpressure to individual upstream source processors.

      The downstream's local parallelism must not be less than the upstream's. This policy is only available on a local edge.


      public static final Edge.RoutingPolicy PARTITIONED
      Each item is sent to the one processor responsible for the item's partition ID. On a distributed edge the processor is unique across the cluster; on a non-distributed edge the processor is unique only within a member.

      public static final Edge.RoutingPolicy BROADCAST
      Each item is sent to all candidate processors.
  • Method Details

    • values

      public static Edge.RoutingPolicy[] values()
      Returns an array containing the constants of this enum type, in the order they are declared.
      an array containing the constants of this enum type, in the order they are declared
    • valueOf

      public static Edge.RoutingPolicy valueOf​(String name)
      Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
      name - the name of the enum constant to be returned.
      the enum constant with the specified name
      IllegalArgumentException - if this enum type has no constant with the specified name
      NullPointerException - if the argument is null