org.apache.flink.runtime.state

Class AbstractStateBackend

java.lang.Object

org.apache.flink.runtime.state.AbstractStateBackend

All Implemented Interfaces:

Serializable, StateBackend

Direct Known Subclasses:

AbstractFileStateBackend

@PublicEvolving
public abstract class AbstractStateBackend
extends Object
implements StateBackend, Serializable

An abstract base implementation of the StateBackend interface.

This class has currently no contents and only kept to not break the prior class hierarchy for users.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
AbstractStateBackend()

Method Summary

Modifier and Type	Method and Description
abstract <K> AbstractKeyedStateBackend<K>	createKeyedStateBackend(Environment env, org.apache.flink.api.common.JobID jobID, String operatorIdentifier, org.apache.flink.api.common.typeutils.TypeSerializer<K> keySerializer, int numberOfKeyGroups, KeyGroupRange keyGroupRange, TaskKvStateRegistry kvStateRegistry, TtlTimeProvider ttlTimeProvider, org.apache.flink.metrics.MetricGroup metricGroup) Creates a new AbstractKeyedStateBackend that is responsible for holding keyed state and checkpointing it.
abstract OperatorStateBackend	createOperatorStateBackend(Environment env, String operatorIdentifier) Creates a new OperatorStateBackend that can be used for storing operator state.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.runtime.state.StateBackend

createCheckpointStorage, createKeyedStateBackend, createKeyedStateBackend, resolveCheckpoint

Constructor Detail

AbstractStateBackend

public AbstractStateBackend()

Method Detail

createKeyedStateBackend

public abstract <K> AbstractKeyedStateBackend<K> createKeyedStateBackend(Environment env,
                                                                         org.apache.flink.api.common.JobID jobID,
                                                                         String operatorIdentifier,
                                                                         org.apache.flink.api.common.typeutils.TypeSerializer<K> keySerializer,
                                                                         int numberOfKeyGroups,
                                                                         KeyGroupRange keyGroupRange,
                                                                         TaskKvStateRegistry kvStateRegistry,
                                                                         TtlTimeProvider ttlTimeProvider,
                                                                         org.apache.flink.metrics.MetricGroup metricGroup)
                                                                  throws IOException

Description copied from interface: StateBackend

Creates a new AbstractKeyedStateBackend that is responsible for holding keyed state and checkpointing it.

Keyed State is state where each value is bound to a key.

Specified by:

createKeyedStateBackend in interface StateBackend

Type Parameters:

K - The type of the keys by which the state is organized.

Returns:

The Keyed State Backend for the given job, operator, and key group range.

Throws:

IOException

createOperatorStateBackend

public abstract OperatorStateBackend createOperatorStateBackend(Environment env,
                                                                String operatorIdentifier)
                                                         throws Exception

Description copied from interface: StateBackend

Creates a new OperatorStateBackend that can be used for storing operator state.

Operator state is state that is associated with parallel operator (or function) instances, rather than with keys.

Specified by:

createOperatorStateBackend in interface StateBackend

Parameters:

env - The runtime environment of the executing task.

operatorIdentifier - The identifier of the operator whose state should be stored.

Returns:

The OperatorStateBackend for operator identified by the job and operator identifier.

Throws:

Exception - This method may forward all exceptions that occur while instantiating the backend.