Class ComplexSink<R>

    • Constructor Detail

      • ComplexSink

        public ComplexSink​(Sink<R> sink)
    • Method Detail

      • initState

        public void initState​(State<Serializable,​Serializable> startupState)
        Description copied from interface: IStatefulComponent
        Initializes the state of the function or operator to that of a previous checkpoint. This method is invoked when a component is executed as part of a recovery run. In case there was prior state associated with the component, the state will be empty. Stateful Spouts/Bolts are expected to hold on to the state variable to save their internal state

        Note that initialState() is called before open() or prepare().

        Specified by:
        initState in interface IStatefulComponent<Serializable,​Serializable>
        Parameters:
        startupState - the previously saved state of the component.
      • prepare

        public void prepare​(Map<String,​Object> map,
                            TopologyContext topologyContext,
                            OutputCollector outputCollector)
        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
        Overrides:
        prepare in class StreamletOperator<R,​R>
        Parameters:
        map - The Heron configuration for this bolt. This is the configuration provided to the topology merged in with cluster configuration on this machine.
        topologyContext - 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.
        outputCollector - 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.
      • execute

        public void execute​(Tuple tuple)
        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, Heron 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
        Parameters:
        tuple - The input tuple to be processed.