org.apache.storm.trident.spout

Interface ITridentSpout.BatchCoordinator<X>

All Known Implementing Classes:

BatchSpoutExecutor.EmptyCoordinator, FeederBatchSpout.FeederCoordinator, OpaquePartitionedTridentSpoutExecutor.Coordinator

Enclosing interface:

ITridentSpout<T>

public static interface ITridentSpout.BatchCoordinator<X>

Method Summary

Modifier and Type	Method and Description
void	close() Release any resources from this coordinator.
X	initializeTransaction(long txid, X prevMetadata, X 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.

Method Detail

initializeTransaction

X initializeTransaction(long txid,
                        X prevMetadata,
                        X currMetadata)

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.

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

success

void success(long txid)

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

Parameters:

txid - transaction id that completed

isReady

boolean isReady(long txid)

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

Parameters:

txid - the id of the transaction

Returns:

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

close

void close()

Release any resources from this coordinator.