Package org.apache.storm.topology

Interface IStatefulBolt<T extends State>

All Superinterfaces:

IComponent, IStatefulComponent<T>, Serializable

All Known Implementing Classes:

BaseStatefulBolt, PersistentWindowedBoltExecutor, StatefulWindowedBoltExecutor, StatefulWordCounter

public interface IStatefulBolt<T extends State>
extends IStatefulComponent<T>

A bolt abstraction for supporting stateful computation. The state of the bolt is periodically checkpointed.

The framework provides at-least once guarantee for the state updates. The stateful bolts are expected to anchor the tuples while emitting and ack the input tuples once its processed.

Method Summary

Modifier and Type	Method	Description
void	cleanup()	Analogue to bolt function.
void	execute(Tuple input)	Analogue to bolt function.
void	prepare(Map<String,Object> topoConf, TopologyContext context, OutputCollector collector)	Analogue to bolt function.

Methods inherited from interface org.apache.storm.topology.IComponent

declareOutputFields, getComponentConfiguration

Methods inherited from interface org.apache.storm.topology.IStatefulComponent

initState, preCommit, prePrepare, preRollback

Method Details

prepare

void prepare(Map<String,Object> topoConf,
 TopologyContext context,
 OutputCollector collector)

Analogue to bolt function.

See Also:

• IBolt.prepare(Map, TopologyContext, OutputCollector)

execute

void execute(Tuple input)

Analogue to bolt function.

See Also:

• IBolt.execute(Tuple)

cleanup

void cleanup()

Analogue to bolt function.

See Also:

• IBolt.cleanup()