public class StatefulWindowedBoltExecutor<T extends State> extends WindowedBoltExecutor implements IStatefulBolt<T>
Wraps a IStatefulWindowedBolt and handles the execution. Saves the last expired and evaluated states of the window during checkpoint and restores the state during recovery.
LATE_TUPLE_FIELD| Constructor and Description |
|---|
StatefulWindowedBoltExecutor(IStatefulWindowedBolt<T> bolt) |
| Modifier and Type | Method and Description |
|---|---|
void |
execute(Tuple input)
Process a single tuple of input.
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void |
initState(T state)
This method is invoked by the framework with the previously saved state of the component.
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protected WindowLifecycleListener<Tuple> |
newWindowLifecycleListener() |
void |
preCommit(long txid)
This is a hook for the component to perform some actions just before the framework commits its state.
|
void |
prepare(Map<String,Object> topoConf,
TopologyContext context,
OutputCollector collector)
Called when a task for this component is initialized within a worker on the cluster.
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void |
prePrepare(long txid)
This is a hook for the component to perform some actions just before the framework prepares its state.
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void |
preRollback()
This is a hook for the component to perform some actions just before the framework rolls back the prepared state.
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protected void |
start()
Start the trigger policy and waterMarkEventGenerator if set.
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boltExecute, boltExecute, cleanup, declareOutputFields, doPrepare, getComponentConfiguration, getState, getTopologyTimeoutMillis, restoreState, validateclone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitcleanupdeclareOutputFields, getComponentConfigurationpublic StatefulWindowedBoltExecutor(IStatefulWindowedBolt<T> bolt)
public void prepare(Map<String,Object> topoConf, TopologyContext context, OutputCollector collector)
IBoltCalled when a task for this component is initialized within a worker on the cluster. It provides the bolt with the environment in which the bolt executes.
This includes the:
prepare in interface IBoltprepare in interface IStatefulBolt<T extends State>prepare in class WindowedBoltExecutortopoConf - The Storm configuration for this bolt. This is the configuration provided to the topology merged in with cluster configuration on this machine.context - This object can be used to get information about this task’s place within the topology, including the task id and component id of this task, input and output information, etc.collector - The collector is used to emit tuples from this bolt. Tuples can be emitted at any time, including the prepare and cleanup methods. The collector is thread-safe and should be saved as an instance variable of this bolt object.IBolt.prepare(Map, TopologyContext, OutputCollector)public void execute(Tuple input)
IBoltProcess a single tuple of input. The Tuple object contains metadata on it about which component/stream/task it came from. The values of the Tuple can be accessed using Tuple#getValue. The IBolt does not have to process the Tuple immediately. It is perfectly fine to hang onto a tuple and process it later (for instance, to do an aggregation or join).
Tuples should be emitted using the OutputCollector provided through the prepare method. It is required that all input tuples are acked or failed at some point using the OutputCollector. Otherwise, Storm will be unable to determine when tuples coming off the spouts have been completed.
For the common case of acking an input tuple at the end of the execute method, see IBasicBolt which automates this.
execute in interface IBoltexecute in interface IStatefulBolt<T extends State>execute in class WindowedBoltExecutorinput - The input tuple to be processed.IBolt.execute(Tuple)protected void start()
WindowedBoltExecutorStart the trigger policy and waterMarkEventGenerator if set.
start in class WindowedBoltExecutorpublic void initState(T state)
IStatefulComponentThis 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.
initState in interface IStatefulComponent<T extends State>state - the previously saved state of the component.public void preCommit(long txid)
IStatefulComponentThis is a hook for the component to perform some actions just before the framework commits its state.
preCommit in interface IStatefulComponent<T extends State>public void prePrepare(long txid)
IStatefulComponentThis is a hook for the component to perform some actions just before the framework prepares its state.
prePrepare in interface IStatefulComponent<T extends State>public void preRollback()
IStatefulComponentThis is a hook for the component to perform some actions just before the framework rolls back the prepared state.
preRollback in interface IStatefulComponent<T extends State>protected WindowLifecycleListener<Tuple> newWindowLifecycleListener()
newWindowLifecycleListener in class WindowedBoltExecutorCopyright © 2020 The Apache Software Foundation. All rights reserved.