org.apache.storm.trident.spout

Interface ITridentSpout<T>

All Superinterfaces:

ITridentDataSource, Serializable

All Known Subinterfaces:

ICommitterTridentSpout<X>

All Known Implementing Classes:

BatchSpoutExecutor, FeederBatchSpout, FeederCommitterBatchSpout, OpaquePartitionedTridentSpoutExecutor, PartitionedTridentSpoutExecutor, RichSpoutBatchExecutor, TridentJmsSpout

public interface ITridentSpout<T>
extends ITridentDataSource

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	ITridentSpout.BatchCoordinator<X>
static interface	ITridentSpout.Emitter<X>

Method Summary

Modifier and Type	Method and Description
Map<String,Object>	getComponentConfiguration()
ITridentSpout.BatchCoordinator<T>	getCoordinator(String txStateId, Map<String,Object> conf, TopologyContext context) The coordinator for a TransactionalSpout runs in a single thread and indicates when batches of tuples should be emitted.
ITridentSpout.Emitter<T>	getEmitter(String txStateId, Map<String,Object> conf, TopologyContext context) The emitter for a TransactionalSpout runs as many tasks across the cluster.
Fields	getOutputFields()

Method Detail

getCoordinator

ITridentSpout.BatchCoordinator<T> getCoordinator(String txStateId,
                                                 Map<String,Object> conf,
                                                 TopologyContext context)

The coordinator for a TransactionalSpout runs in a single thread and indicates when batches of tuples should be emitted. The Coordinator that you provide in a TransactionalSpout provides metadata for each transaction so that the transactions can be replayed in case of failure.

Two instances are requested, one on the master batch coordinator where isReady() is called, and an instance in the coordinator bolt which is used for all other operations. The two instances do not necessarily share a worker JVM.

Parameters:

txStateId - stream id

conf - Storm config map

context - topology context

Returns:

spout coordinator instance

getEmitter

ITridentSpout.Emitter<T> getEmitter(String txStateId,
                                    Map<String,Object> conf,
                                    TopologyContext context)

The emitter for a TransactionalSpout runs as many tasks across the cluster. Emitters are responsible for emitting batches of tuples for a transaction and must ensure that the same batch of tuples is always emitted for the same transaction id.

All emitter tasks get the same transaction metadata. The topology context parameter contains the instance task id that can be used to distribute the work across the tasks.

Parameters:

txStateId - stream id

conf - Storm config map

context - topology context

Returns:

spout emitter

getComponentConfiguration

Map<String,Object> getComponentConfiguration()

getOutputFields

Fields getOutputFields()