Interface IStatefulComponent<T extends State>

All Superinterfaces:
IComponent, Serializable
All Known Subinterfaces:
IStatefulBolt<T>, IStatefulWindowedBolt<T>
All Known Implementing Classes:
BaseStatefulBolt, BaseStatefulWindowedBolt, PersistentWindowedBoltExecutor, StatefulWindowedBoltExecutor, StatefulWordCounter

public interface IStatefulComponent<T extends State> extends IComponent

Common methods for stateful components in the topology.

A stateful component is one that has state (e.g. the result of some computation in a bolt) and wants the framework to manage its state.
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    initState(T state)
    This method is invoked by the framework with the previously saved state of the component.
    void
    preCommit(long txid)
    This is a hook for the component to perform some actions just before the framework commits its state.
    void
    prePrepare(long txid)
    This is a hook for the component to perform some actions just before the framework prepares its state.
    void
    This is a hook for the component to perform some actions just before the framework rolls back the prepared state.

    Methods inherited from interface org.apache.storm.topology.IComponent

    declareOutputFields, getComponentConfiguration
  • Method Details

    • initState

      void initState(T state)
      This method is invoked by the framework with the previously saved state of the component. This is invoked after prepare but before the component starts processing tuples.
      Parameters:
      state - the previously saved state of the component.
    • preCommit

      void preCommit(long txid)
      This is a hook for the component to perform some actions just before the framework commits its state.
    • prePrepare

      void prePrepare(long txid)
      This is a hook for the component to perform some actions just before the framework prepares its state.
    • preRollback

      void preRollback()
      This is a hook for the component to perform some actions just before the framework rolls back the prepared state.