org.apache.storm.trident.spout

Class BatchSpoutExecutor.EmptyCoordinator

java.lang.Object

org.apache.storm.trident.spout.BatchSpoutExecutor.EmptyCoordinator

All Implemented Interfaces:

ITridentSpout.BatchCoordinator<Object>

Enclosing class:

BatchSpoutExecutor

public static class BatchSpoutExecutor.EmptyCoordinator
extends Object
implements ITridentSpout.BatchCoordinator<Object>

Constructor Summary

Constructors

Constructor and Description
EmptyCoordinator()

Method Summary

Modifier and Type	Method and Description
void	close() Release any resources from this coordinator.
Object	initializeTransaction(long txid, Object prevMetadata, Object currMetadata) Create metadata for this particular transaction id which has never been emitted before.
boolean	isReady(long txid) hint to Storm if the spout is ready for the transaction id.
void	success(long txid) This attempt committed successfully, so all state for this commit and before can be safely cleaned up.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

EmptyCoordinator

public EmptyCoordinator()

Method Detail

initializeTransaction

public Object initializeTransaction(long txid,
                                    Object prevMetadata,
                                    Object currMetadata)

Description copied from interface: ITridentSpout.BatchCoordinator

Create metadata for this particular transaction id which has never been emitted before. The metadata should contain whatever is necessary to be able to replay the exact batch for the transaction at a later point.

The metadata is stored in Zookeeper.

Storm uses JSON encoding to store the metadata. Only simple types such as numbers, booleans, strings, lists, and maps should be used.

Specified by:

initializeTransaction in interface ITridentSpout.BatchCoordinator<Object>

Parameters:

txid - The id of the transaction.

prevMetadata - The metadata of the previous transaction

currMetadata - The metadata for this transaction the last time it was initialized. null if this is the first attempt

Returns:

the metadata for this new transaction

close

public void close()

Description copied from interface: ITridentSpout.BatchCoordinator

Release any resources from this coordinator.

Specified by:

close in interface ITridentSpout.BatchCoordinator<Object>

success

public void success(long txid)

Description copied from interface: ITridentSpout.BatchCoordinator

This attempt committed successfully, so all state for this commit and before can be safely cleaned up.

Specified by:

success in interface ITridentSpout.BatchCoordinator<Object>

Parameters:

txid - transaction id that completed

isReady

public boolean isReady(long txid)

Description copied from interface: ITridentSpout.BatchCoordinator

hint to Storm if the spout is ready for the transaction id.

Specified by:

isReady in interface ITridentSpout.BatchCoordinator<Object>

Parameters:

txid - the id of the transaction

Returns:

true, if the spout is ready for the given transaction id