Package kalix.javasdk.replicatedentity

Interface ReplicatedRegister<T>

Type Parameters:
T -
All Superinterfaces:
kalix.replicatedentity.ReplicatedData
public interface ReplicatedRegister<T> extends kalix.replicatedentity.ReplicatedData
A Last-Write-Wins Register.

This uses a clock value to determine which of two concurrent writes should win. When both clock values are the same, an ordering defined over the node addresses is used to break the tie.

By default, the clock used is the clock of the node that set the value. This can be affected by clock skew, which means two successive writes delegated to two separate nodes could result in the first one winning. This can be avoided by using a custom clock with a domain specific clock value, if such a causally ordered value is available.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Interface
    Description
    static enum 
    ReplicatedRegister.Clock
    Clock for register replication

  • Method Summary

    Modifier and Type
    Method
    Description
    T
    get()
    Get the current value of the register.
    default ReplicatedRegister<T>
    set(T value)
    Set the value of the register, using the default clock.
    ReplicatedRegister<T>
    set(T value, ReplicatedRegister.Clock clock, long customClockValue)
    Set the current value of the register, using the given custom clock and clock value if required.

  • Method Details

    • get

      T get()
      Get the current value of the register.
      Returns:
      the current value of the register

    • set

      default ReplicatedRegister<T> set(T value)
      Set the value of the register, using the default clock.
      Parameters:
      value - the new value of the register
      Returns:
      a new register with updated value

    • set

      ReplicatedRegister<T> set(T value, ReplicatedRegister.Clock clock, long customClockValue)
      Set the current value of the register, using the given custom clock and clock value if required.
      Parameters:
      value - the new value of the register
      clock - the clock to use for replication
      customClockValue - the custom clock value to use, only if it's a custom clock
      Returns:
      a new register with updated value