org.apache.flink.contrib.streaming.state

Class RocksDBFoldingState<K,N,T,ACC>

java.lang.Object

org.apache.flink.contrib.streaming.state.AbstractRocksDBState<K,N,FoldingState<T,ACC>,FoldingStateDescriptor<T,ACC>>

org.apache.flink.contrib.streaming.state.RocksDBFoldingState<K,N,T,ACC>

Type Parameters:

K - The type of the key.

N - The type of the namespace.

T - The type of the values that can be folded into the state.

ACC - The type of the value in the folding state.

All Implemented Interfaces:

FoldingState<T,ACC>, MergingState<T,ACC>, State, KvState<K,N,FoldingState<T,ACC>,FoldingStateDescriptor<T,ACC>,RocksDBStateBackend>

public class RocksDBFoldingState<K,N,T,ACC>
extends AbstractRocksDBState<K,N,FoldingState<T,ACC>,FoldingStateDescriptor<T,ACC>>
implements FoldingState<T,ACC>

FoldingState implementation that stores state in RocksDB.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.flink.contrib.streaming.state.AbstractRocksDBState

AbstractRocksDBState.AbstractRocksDBSnapshot<K,N,S extends State,SD extends StateDescriptor<S,?>>

Field Summary

Fields

Modifier and Type	Field and Description
protected FoldingStateDescriptor<T,ACC>	stateDesc This holds the name of the state and can create an initial default value for the state.
protected org.rocksdb.WriteOptions	writeOptions We disable writes to the write-ahead-log here.

Fields inherited from class org.apache.flink.contrib.streaming.state.AbstractRocksDBState

basePath, checkpointPath, currentKey, currentNamespace, db, keySerializer, namespaceSerializer, rocksDbPath

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	RocksDBFoldingState(TypeSerializer<K> keySerializer, TypeSerializer<N> namespaceSerializer, FoldingStateDescriptor<T,ACC> stateDesc, File dbPath, String backupPath, org.rocksdb.Options options) Creates a new RocksDBFoldingState.
protected	RocksDBFoldingState(TypeSerializer<K> keySerializer, TypeSerializer<N> namespaceSerializer, FoldingStateDescriptor<T,ACC> stateDesc, File dbPath, String backupPath, String restorePath, org.rocksdb.Options options) Creates a RocksDBFoldingState by restoring from a directory.

Method Summary

Modifier and Type	Method and Description
void	add(T value) Updates the operator state accessible by MergingState.get() by adding the given value to the list of values.
protected AbstractRocksDBState.AbstractRocksDBSnapshot<K,N,FoldingState<T,ACC>,FoldingStateDescriptor<T,ACC>>	createRocksDBSnapshot(URI backupUri, long checkpointId)
ACC	get() Returns the current value for the state.

Methods inherited from class org.apache.flink.contrib.streaming.state.AbstractRocksDBState

clear, dispose, setCurrentKey, setCurrentNamespace, snapshot, writeKeyAndNamespace

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.api.common.state.State

clear

Field Detail

stateDesc

protected final FoldingStateDescriptor<T,ACC> stateDesc

This holds the name of the state and can create an initial default value for the state.

writeOptions

protected final org.rocksdb.WriteOptions writeOptions

We disable writes to the write-ahead-log here. We can't have these in the base class because JNI segfaults for some reason if they are.

Constructor Detail

RocksDBFoldingState

protected RocksDBFoldingState(TypeSerializer<K> keySerializer,
                              TypeSerializer<N> namespaceSerializer,
                              FoldingStateDescriptor<T,ACC> stateDesc,
                              File dbPath,
                              String backupPath,
                              org.rocksdb.Options options)

Creates a new RocksDBFoldingState.

Parameters:

keySerializer - The serializer for the keys.

namespaceSerializer - The serializer for the namespace.

stateDesc - The state identifier for the state. This contains name and can create a default state value.

dbPath - The path on the local system where RocksDB data should be stored.

backupPath - The path where to store backups.

RocksDBFoldingState

protected RocksDBFoldingState(TypeSerializer<K> keySerializer,
                              TypeSerializer<N> namespaceSerializer,
                              FoldingStateDescriptor<T,ACC> stateDesc,
                              File dbPath,
                              String backupPath,
                              String restorePath,
                              org.rocksdb.Options options)

Creates a RocksDBFoldingState by restoring from a directory.

Parameters:

keySerializer - The serializer for the keys.

namespaceSerializer - The serializer for the namespace.

stateDesc - The state identifier for the state. This contains name and can create a default state value.

dbPath - The path on the local system where RocksDB data should be stored.

backupPath - The path where to store backups.

restorePath - The path on the local file system that we are restoring from.

Method Detail

get

public ACC get()

Description copied from interface: MergingState

Returns the current value for the state. When the state is not partitioned the returned value is the same for all inputs in a given operator instance. If state partitioning is applied, the value returned depends on the current operator input, as the operator maintains an independent state for each partition.

Specified by:

get in interface MergingState<T,ACC>

Returns:

The operator state value corresponding to the current input.

add

public void add(T value)
         throws IOException

Description copied from interface: MergingState

Updates the operator state accessible by MergingState.get() by adding the given value to the list of values. The next time MergingState.get() is called (for the same state partition) the returned state will represent the updated list.

Specified by:

add in interface MergingState<T,ACC>

Parameters:

value - The new value for the state.

Throws:

IOException - Thrown if the system cannot access the state.

createRocksDBSnapshot

protected AbstractRocksDBState.AbstractRocksDBSnapshot<K,N,FoldingState<T,ACC>,FoldingStateDescriptor<T,ACC>> createRocksDBSnapshot(URI backupUri,
                                                                                                                                    long checkpointId)

Specified by:

createRocksDBSnapshot in class AbstractRocksDBState<K,N,FoldingState<T,ACC>,FoldingStateDescriptor<T,ACC>>