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 Filters and Functions.

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.