org.apache.samza.storage

Interface StorageEngine

public interface StorageEngine

A storage engine for managing state maintained by a stream processor.

This interface does not specify any query capabilities, which, of course, would be query engine specific. Instead it just specifies the minimum functionality required to reload a storage engine from its changelog as well as basic lifecycle management.

Method Summary

Modifier and Type	Method and Description
void	flush() Flush any cached messages
void	restore(java.util.Iterator<IncomingMessageEnvelope> envelopes) Restore the content of this StorageEngine from the changelog.
void	stop() Close the storage engine

Method Detail

restore

void restore(java.util.Iterator<IncomingMessageEnvelope> envelopes)

Restore the content of this StorageEngine from the changelog. Messages are provided in one Iterator and not deserialized for efficiency, allowing the implementation to optimize replay, if possible.

Parameters:

envelopes - An iterator of envelopes that the storage engine can read from to restore its state on startup.

flush

void flush()

Flush any cached messages

stop

void stop()

Close the storage engine