org.apache.flink.state.forst

Class ForStKeyedStateBackend<K>

java.lang.Object

org.apache.flink.state.forst.ForStKeyedStateBackend<K>

All Implemented Interfaces:

Closeable, AutoCloseable, AsyncKeyedStateBackend, Disposable

public class ForStKeyedStateBackend<K>
extends Object
implements AsyncKeyedStateBackend

A KeyedStateBackend that stores its state in ForSt. This state backend can store very large state that exceeds memory even disk to remote storage.

Field Summary

Fields

Modifier and Type	Field and Description
protected org.rocksdb.RocksDB	db Our ForSt database.
protected TypeSerializer<K>	keySerializer The key serializer.

Constructor Summary

Constructors

Constructor and Description

ForStKeyedStateBackend(ForStResourceContainer optionsContainer, TypeSerializer<K> keySerializer, Supplier<SerializedCompositeKeyBuilder<K>> serializedKeyBuilder, Supplier<DataOutputSerializer> valueSerializerView, Supplier<DataInputDeserializer> valueDeserializerView, org.rocksdb.RocksDB db, Function<String,org.rocksdb.ColumnFamilyOptions> columnFamilyOptionsFactory, org.rocksdb.ColumnFamilyHandle defaultColumnFamilyHandle, ForStNativeMetricMonitor nativeMetricMonitor)

Method Summary

Modifier and Type	Method and Description
void	close()
<SV,S extends State> S	createState(StateDescriptor<SV> stateDesc) Creates and returns a new state.
StateExecutor	createStateExecutor() Creates a StateExecutor which supports to execute a batch of state requests asynchronously.
void	dispose() Should only be called by one thread, and only after all accesses to the DB happened.
void	setup(StateRequestHandler stateRequestHandler) Initializes with some contexts.

Methods inherited from class java.lang.Object

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

Field Detail

keySerializer

protected final TypeSerializer<K> keySerializer

The key serializer.

db

protected final org.rocksdb.RocksDB db

Our ForSt database. The different k/v states that we have don't each have their own ForSt instance. They all write to this instance but to their own column family.

Constructor Detail

ForStKeyedStateBackend

public ForStKeyedStateBackend(ForStResourceContainer optionsContainer,
                              TypeSerializer<K> keySerializer,
                              Supplier<SerializedCompositeKeyBuilder<K>> serializedKeyBuilder,
                              Supplier<DataOutputSerializer> valueSerializerView,
                              Supplier<DataInputDeserializer> valueDeserializerView,
                              org.rocksdb.RocksDB db,
                              Function<String,org.rocksdb.ColumnFamilyOptions> columnFamilyOptionsFactory,
                              org.rocksdb.ColumnFamilyHandle defaultColumnFamilyHandle,
                              ForStNativeMetricMonitor nativeMetricMonitor)

Method Detail

setup

public void setup(@Nonnull
                  StateRequestHandler stateRequestHandler)

Description copied from interface: AsyncKeyedStateBackend

Initializes with some contexts.

Specified by:

setup in interface AsyncKeyedStateBackend

Parameters:

stateRequestHandler - which handles state request.

createState

@Nonnull
public <SV,S extends State> S createState(@Nonnull
                                                   StateDescriptor<SV> stateDesc)

Description copied from interface: AsyncKeyedStateBackend

Creates and returns a new state.

Specified by:

createState in interface AsyncKeyedStateBackend

Type Parameters:

SV - The type of the stored state value.

S - The type of the public API state.

Parameters:

stateDesc - The StateDescriptor that contains the name of the state.

createStateExecutor

@Nonnull
public StateExecutor createStateExecutor()

Description copied from interface: AsyncKeyedStateBackend

Creates a StateExecutor which supports to execute a batch of state requests asynchronously.

Notice that the AsyncKeyedStateBackend is responsible for shutting down the StateExecutors created by itself when they are no longer in use.

Specified by:

createStateExecutor in interface AsyncKeyedStateBackend

Returns:

a StateExecutor which supports to execute a batch of state requests asynchronously.

dispose

public void dispose()

Should only be called by one thread, and only after all accesses to the DB happened.

Specified by:

dispose in interface AsyncKeyedStateBackend

Specified by:

dispose in interface Disposable

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException