Interface Operation

All Superinterfaces:
All Known Subinterfaces:
Aggregator<T>, EachOperation, Filter, Function, OperationAwareFlatMapFunction, OperationAwareMapFunction, QueryFunction<S,T>, StateUpdater<S>
All Known Implementing Classes:
AbstractRedisStateQuerier, AbstractRedisStateUpdater, BaseAggregator, BaseFilter, BaseFunction, BaseOperation, BaseQueryFunction, BaseStateUpdater, ChainedAggregatorImpl, CombinerAggregatorCombineImpl, CombinerAggregatorInitImpl, CombinerAggStateUpdater, ComparisonAggregator, ConsumerExecutor, CountAsAggregator, Debug, Equals, EsUpdater, FilterExecutor, FilterNull, FirstN.FirstNAgg, FirstN.FirstNSortedAgg, FlatMapFunctionExecutor, GroupedAggregator, HdfsUpdater, HiveUpdater, JdbcQuery, JdbcUpdater, JmsUpdater, MapCombinerAggStateUpdater, MapFunctionExecutor, MapGet, MapReducerAggStateUpdater, Max, MaxWithComparator, Min, MinWithComparator, Negate, PrintFunction, RedisClusterStateQuerier, RedisClusterStateUpdater, RedisStateQuerier, RedisStateUpdater, ReducerAggregatorImpl, ReducerAggStateUpdater, SingleEmitAggregator, SnapshotGet, Split, StringLength, TridentKafkaStateUpdater, TridentReach.ExpandList, TridentWordCount.Split, TrueFilter, TrueFilter, TupleCollectionGet, TuplifyArgs, WindowsStateUpdater

public interface Operation extends Serializable
Parent interface for Trident `Filter`s and `Function`s.

`Operation` defines two lifecycle methods for Trident components. The `prepare()` method is called once when the `Operation` is first initialized. The `cleanup()` method is called in local mode when the local cluster is being shut down. In distributed mode, the `cleanup()` method is not guaranteed to be called in every situation, but Storm will make a best effort call `cleanup()` whenever possible.

  • Method Summary

    Modifier and Type
    When running in local mode, called when the local cluster is being shut down.
    Called when the `Operation` is first initialized.
  • Method Details

    • prepare

      void prepare(Map<String,Object> conf, TridentOperationContext context)
      Called when the `Operation` is first initialized.
      conf - the Storm configuration map
      context - the operation context which provides information such as the number of partitions in the stream, and the current partition index. It also provides methods for registering operation-specific metrics.
      See Also:
    • cleanup

      void cleanup()
      When running in local mode, called when the local cluster is being shut down.