Package org.apache.storm.topology

Class StatefulWindowedBoltExecutor<T extends State>

java.lang.Object
org.apache.storm.topology.WindowedBoltExecutor
org.apache.storm.topology.StatefulWindowedBoltExecutor<T>
All Implemented Interfaces:
Serializable, IBolt, IComponent, IRichBolt, IStatefulBolt<T>, IStatefulComponent<T>
public class StatefulWindowedBoltExecutor<T extends State> extends WindowedBoltExecutor implements IStatefulBolt<T>
Wraps a IStatefulWindowedBolt and handles the execution. Saves the last expired and evaluated states of the window during checkpoint and restores the state during recovery.
See Also:

  • Constructor Details

  • Method Details

    • prepare

      public void prepare(Map<String,Object> topoConf, TopologyContext context, OutputCollector collector)
      Description copied from interface: IBolt
      Called when a task for this component is initialized within a worker on the cluster. It provides the bolt with the environment in which the bolt executes.

      This includes the:

      Specified by:
      prepare in interface IBolt
      Specified by:
      prepare in interface IStatefulBolt<T extends State>
      Overrides:
      prepare in class WindowedBoltExecutor
      Parameters:
      topoConf - The Storm configuration for this bolt. This is the configuration provided to the topology merged in with cluster configuration on this machine.
      context - This object can be used to get information about this task's place within the topology, including the task id and component id of this task, input and output information, etc.
      collector - The collector is used to emit tuples from this bolt. Tuples can be emitted at any time, including the prepare and cleanup methods. The collector is thread-safe and should be saved as an instance variable of this bolt object.
      See Also:

    • execute

      public void execute(Tuple input)
      Description copied from interface: IBolt
      Process a single tuple of input. The Tuple object contains metadata on it about which component/stream/task it came from. The values of the Tuple can be accessed using Tuple#getValue. The IBolt does not have to process the Tuple immediately. It is perfectly fine to hang onto a tuple and process it later (for instance, to do an aggregation or join).

      Tuples should be emitted using the OutputCollector provided through the prepare method. It is required that all input tuples are acked or failed at some point using the OutputCollector. Otherwise, Storm will be unable to determine when tuples coming off the spouts have been completed.

      For the common case of acking an input tuple at the end of the execute method, see IBasicBolt which automates this.

      Specified by:
      execute in interface IBolt
      Specified by:
      execute in interface IStatefulBolt<T extends State>
      Overrides:
      execute in class WindowedBoltExecutor
      Parameters:
      input - The input tuple to be processed.
      See Also:

    • start

      protected void start()
      Description copied from class: WindowedBoltExecutor
      Start the trigger policy and waterMarkEventGenerator if set.
      Overrides:
      start in class WindowedBoltExecutor

    • initState

      public void initState(T state)
      Description copied from interface: IStatefulComponent
      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.
      Specified by:
      initState in interface IStatefulComponent<T extends State>
      Parameters:
      state - the previously saved state of the component.

    • preCommit

      public void preCommit(long txid)
      Description copied from interface: IStatefulComponent
      This is a hook for the component to perform some actions just before the framework commits its state.
      Specified by:
      preCommit in interface IStatefulComponent<T extends State>

    • prePrepare

      public void prePrepare(long txid)
      Description copied from interface: IStatefulComponent
      This is a hook for the component to perform some actions just before the framework prepares its state.
      Specified by:
      prePrepare in interface IStatefulComponent<T extends State>

    • preRollback

      public void preRollback()
      Description copied from interface: IStatefulComponent
      This is a hook for the component to perform some actions just before the framework rolls back the prepared state.
      Specified by:
      preRollback in interface IStatefulComponent<T extends State>

    • newWindowLifecycleListener

      protected WindowLifecycleListener<Tuple> newWindowLifecycleListener()
      Overrides:
      newWindowLifecycleListener in class WindowedBoltExecutor