org.apache.storm.state

Interface State

All Known Subinterfaces:

KeyValueState<K,V>

All Known Implementing Classes:

HBaseKeyValueState, InMemoryKeyValueState, RedisKeyValueState

public interface State

The state of the component that is either managed by the framework (e.g in case of IStatefulBolt) or managed by the the individual components themselves.

Method Summary

Modifier and Type	Method and Description
void	commit() Persist the current state.
void	commit(long txid) Commit a previously prepared transaction.
void	prepareCommit(long txid) Invoked by the framework to prepare a transaction for commit.
void	rollback() Rollback a prepared transaction to the previously committed state.

Method Detail

prepareCommit

void prepareCommit(long txid)

Invoked by the framework to prepare a transaction for commit. It should be possible to commit the prepared state later.

The same txid can be prepared again, but the next txid cannot be prepared when previous one is not yet committed.

Parameters:

txid - the transaction id

commit

void commit(long txid)

Commit a previously prepared transaction. It should be possible to retrieve a committed state later.

Parameters:

txid - the transaction id

commit

void commit()

Persist the current state. This is used when the component manages the state.

rollback

void rollback()

Rollback a prepared transaction to the previously committed state.