org.apache.storm.transactional

Interface ITransactionalSpout.Coordinator<X>

All Known Implementing Classes:

OpaquePartitionedTransactionalSpoutExecutor.Coordinator

Enclosing interface:

ITransactionalSpout<T>

public static interface ITransactionalSpout.Coordinator<X>

Method Summary

Modifier and Type	Method and Description
void	close() Release any resources from this coordinator.
X	initializeTransaction(BigInteger txid, X prevMetadata) Create metadata for this particular transaction id which has never been emitted before.
boolean	isReady() Returns true if its ok to emit start a new transaction, false otherwise (will skip this transaction).

Method Detail

initializeTransaction

X initializeTransaction(BigInteger txid,
                        X prevMetadata)

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 the Kryo serializations configured in the component configuration for this spout to serialize and deserialize the metadata.

Parameters:

txid - The id of the transaction.

prevMetadata - The metadata of the previous transaction

Returns:

the metadata for this new transaction

isReady

boolean isReady()

Returns true if its ok to emit start a new transaction, false otherwise (will skip this transaction).

You should sleep here if you want a delay between asking for the next transaction (this will be called repeatedly in a loop).

close

void close()

Release any resources from this coordinator.