Package org.apache.storm.topology
Interface IStatefulComponent<T extends State>
- All Superinterfaces:
IComponent
,Serializable
- All Known Subinterfaces:
IStatefulBolt<T>
,IStatefulWindowedBolt<T>
- All Known Implementing Classes:
BaseStatefulBolt
,BaseStatefulWindowedBolt
,PersistentWindowedBoltExecutor
,StatefulWindowedBoltExecutor
,StatefulWordCounter
Common methods for stateful components in the topology.
A stateful component is one that has state (e.g. the result of some computation in a bolt) and wants the framework to manage its state.-
Method Summary
Modifier and TypeMethodDescriptionvoid
This method is invoked by the framework with the previously saved state of the component.void
preCommit
(long txid) This is a hook for the component to perform some actions just before the framework commits its state.void
prePrepare
(long txid) This is a hook for the component to perform some actions just before the framework prepares its state.void
This is a hook for the component to perform some actions just before the framework rolls back the prepared state.Methods inherited from interface org.apache.storm.topology.IComponent
declareOutputFields, getComponentConfiguration
-
Method Details
-
initState
This method is invoked by the framework with the previously saved state of the component. This is invoked after prepare but before the component starts processing tuples.- Parameters:
state
- the previously saved state of the component.
-
preCommit
void preCommit(long txid) This is a hook for the component to perform some actions just before the framework commits its state. -
prePrepare
void prePrepare(long txid) This is a hook for the component to perform some actions just before the framework prepares its state. -
preRollback
void preRollback()This is a hook for the component to perform some actions just before the framework rolls back the prepared state.
-