org.apache.storm.trident.operation

Interface Operation

All Superinterfaces:

Serializable

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, CassandraQuery, CassandraStateUpdater, ChainedAggregatorImpl, CombinerAggregatorCombineImpl, CombinerAggregatorInitImpl, CombinerAggStateUpdater, ComparisonAggregator, ConsumerExecutor, CountAsAggregator, Debug, Equals, EsUpdater, FilterExecutor, FilterNull, FirstN.FirstNAgg, FirstN.FirstNSortedAgg, FlatMapFunctionExecutor, GroupedAggregator, HBaseQuery, HBaseUpdater, HdfsUpdater, HiveUpdater, JdbcQuery, JdbcUpdater, JmsUpdater, MapCombinerAggStateUpdater, MapFunctionExecutor, MapGet, MapReducerAggStateUpdater, Max, MaxWithComparator, Min, MinWithComparator, MongoStateQuery, MongoStateUpdater, MqttPublishFunction, Negate, OpenTsdbStateUpdater, PrintFunction, PrintFunction, PrintFunction, RedisClusterStateQuerier, RedisClusterStateUpdater, RedisStateQuerier, RedisStateUpdater, ReducerAggregatorImpl, ReducerAggStateUpdater, RocketMqStateUpdater, SingleEmitAggregator, SnapshotGet, SolrUpdater, 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	Method and Description
void	cleanup() When running in local mode, called when the local cluster is being shut down.
void	prepare(Map<String,Object> conf, TridentOperationContext context) Called when the `Operation` is first initialized.

Method Detail

prepare

void prepare(Map<String,Object> conf,
             TridentOperationContext context)

Called when the `Operation` is first initialized.

Parameters:

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:

TridentOperationContext

cleanup

void cleanup()

When running in local mode, called when the local cluster is being shut down.