org.apache.flink.contrib.streaming.state

Class RocksDBStateBackend

java.lang.Object

org.apache.flink.runtime.state.AbstractStateBackend

org.apache.flink.contrib.streaming.state.RocksDBStateBackend

All Implemented Interfaces:

Serializable, org.apache.flink.runtime.state.ConfigurableStateBackend, org.apache.flink.runtime.state.StateBackend

public class RocksDBStateBackend
extends org.apache.flink.runtime.state.AbstractStateBackend
implements org.apache.flink.runtime.state.ConfigurableStateBackend

A State Backend that stores its state in RocksDB. This state backend can store very large state that exceeds memory and spills to disk.

All key/value state (including windows) is stored in the key/value index of RocksDB. For persistence against loss of machines, checkpoints take a snapshot of the RocksDB database, and persist that snapshot in a file system (by default) or another configurable state backend.

The behavior of the RocksDB instances can be parametrized by setting RocksDB Options using the methods setPredefinedOptions(PredefinedOptions) and setRocksDBOptions(RocksDBOptionsFactory).

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RocksDBStateBackend.PriorityQueueStateType The options to chose for the type of priority queue state.

Constructor Summary

Constructors

Constructor and Description
RocksDBStateBackend(org.apache.flink.runtime.state.AbstractStateBackend checkpointStreamBackend) Deprecated. Use RocksDBStateBackend(StateBackend) instead.
RocksDBStateBackend(org.apache.flink.runtime.state.AbstractStateBackend checkpointStreamBackend, boolean enableIncrementalCheckpointing) Deprecated. Use RocksDBStateBackend(StateBackend, TernaryBoolean) instead.
RocksDBStateBackend(org.apache.flink.runtime.state.StateBackend checkpointStreamBackend) Creates a new RocksDBStateBackend that uses the given state backend to store its checkpoint data streams.
RocksDBStateBackend(org.apache.flink.runtime.state.StateBackend checkpointStreamBackend, org.apache.flink.util.TernaryBoolean enableIncrementalCheckpointing) Creates a new RocksDBStateBackend that uses the given state backend to store its checkpoint data streams.
RocksDBStateBackend(String checkpointDataUri) Creates a new RocksDBStateBackend that stores its checkpoint data in the file system and location defined by the given URI.
RocksDBStateBackend(String checkpointDataUri, boolean enableIncrementalCheckpointing) Creates a new RocksDBStateBackend that stores its checkpoint data in the file system and location defined by the given URI.
RocksDBStateBackend(URI checkpointDataUri) Creates a new RocksDBStateBackend that stores its checkpoint data in the file system and location defined by the given URI.
RocksDBStateBackend(URI checkpointDataUri, boolean enableIncrementalCheckpointing) Creates a new RocksDBStateBackend that stores its checkpoint data in the file system and location defined by the given URI.

Method Summary

Modifier and Type	Method and Description
RocksDBStateBackend	configure(org.apache.flink.configuration.ReadableConfig config, ClassLoader classLoader) Creates a copy of this state backend that uses the values defined in the configuration for fields where that were not yet specified in this state backend.
org.apache.flink.runtime.state.CheckpointStorage	createCheckpointStorage(org.apache.flink.api.common.JobID jobId)
<K> org.apache.flink.runtime.state.AbstractKeyedStateBackend<K>	createKeyedStateBackend(org.apache.flink.runtime.execution.Environment env, org.apache.flink.api.common.JobID jobID, String operatorIdentifier, org.apache.flink.api.common.typeutils.TypeSerializer<K> keySerializer, int numberOfKeyGroups, org.apache.flink.runtime.state.KeyGroupRange keyGroupRange, org.apache.flink.runtime.query.TaskKvStateRegistry kvStateRegistry, org.apache.flink.runtime.state.ttl.TtlTimeProvider ttlTimeProvider, org.apache.flink.metrics.MetricGroup metricGroup, Collection<org.apache.flink.runtime.state.KeyedStateHandle> stateHandles, org.apache.flink.core.fs.CloseableRegistry cancelStreamRegistry)
org.apache.flink.runtime.state.OperatorStateBackend	createOperatorStateBackend(org.apache.flink.runtime.execution.Environment env, String operatorIdentifier, Collection<org.apache.flink.runtime.state.OperatorStateHandle> stateHandles, org.apache.flink.core.fs.CloseableRegistry cancelStreamRegistry)
org.apache.flink.runtime.state.StateBackend	getCheckpointBackend() Gets the state backend that this RocksDB state backend uses to persist its bytes to.
String[]	getDbStoragePaths() Gets the configured local DB storage paths, or null, if none were configured.
RocksDBMemoryConfiguration	getMemoryConfiguration() Gets the memory configuration object, which offers settings to control RocksDB's memory usage.
int	getNumberOfTransferingThreads() Deprecated. Typo in method name. Use getNumberOfTransferThreads() instead.
int	getNumberOfTransferThreads() Gets the number of threads used to transfer files while snapshotting/restoring.
PredefinedOptions	getPredefinedOptions() Gets the currently set predefined options for RocksDB.
RocksDBStateBackend.PriorityQueueStateType	getPriorityQueueStateType() Gets the type of the priority queue state.
RocksDBOptionsFactory	getRocksDBOptions() Gets Options for the RocksDB instances.
long	getWriteBatchSize() Gets the max batch size will be used in RocksDBWriteBatchWrapper.
boolean	isIncrementalCheckpointsEnabled() Gets whether incremental checkpoints are enabled for this state backend.
org.apache.flink.runtime.state.CompletedCheckpointStorageLocation	resolveCheckpoint(String pointer)
void	setDbStoragePath(String path) Sets the path where the RocksDB local database files should be stored on the local file system.
void	setDbStoragePaths(String... paths) Sets the directories in which the local RocksDB database puts its files (like SST and metadata files).
void	setNumberOfTransferingThreads(int numberOfTransferingThreads) Deprecated. Typo in method name. Use setNumberOfTransferThreads(int) instead.
void	setNumberOfTransferThreads(int numberOfTransferThreads) Sets the number of threads used to transfer files while snapshotting/restoring.
void	setPredefinedOptions(PredefinedOptions options) Sets the predefined options for RocksDB.
void	setPriorityQueueStateType(RocksDBStateBackend.PriorityQueueStateType priorityQueueStateType) Sets the type of the priority queue state.
void	setRocksDBOptions(RocksDBOptionsFactory optionsFactory) Sets Options for the RocksDB instances.
void	setWriteBatchSize(long writeBatchSize) Sets the max batch size will be used in RocksDBWriteBatchWrapper, no positive value will disable memory size controller, just use item count controller.
String	toString()

Methods inherited from class org.apache.flink.runtime.state.AbstractStateBackend

getCompressionDecorator

Methods inherited from class java.lang.Object

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

Constructor Detail

RocksDBStateBackend

public RocksDBStateBackend(String checkpointDataUri)
                    throws IOException

Creates a new RocksDBStateBackend that stores its checkpoint data in the file system and location defined by the given URI.

A state backend that stores checkpoints in HDFS or S3 must specify the file system host and port in the URI, or have the Hadoop configuration that describes the file system (host / high-availability group / possibly credentials) either referenced from the Flink config, or included in the classpath.

Parameters:

checkpointDataUri - The URI describing the filesystem and path to the checkpoint data directory.

Throws:

IOException - Thrown, if no file system can be found for the scheme in the URI.

RocksDBStateBackend

public RocksDBStateBackend(String checkpointDataUri,
                           boolean enableIncrementalCheckpointing)
                    throws IOException

Creates a new RocksDBStateBackend that stores its checkpoint data in the file system and location defined by the given URI.

A state backend that stores checkpoints in HDFS or S3 must specify the file system host and port in the URI, or have the Hadoop configuration that describes the file system (host / high-availability group / possibly credentials) either referenced from the Flink config, or included in the classpath.

Parameters:

checkpointDataUri - The URI describing the filesystem and path to the checkpoint data directory.

enableIncrementalCheckpointing - True if incremental checkpointing is enabled.

Throws:

IOException - Thrown, if no file system can be found for the scheme in the URI.

RocksDBStateBackend

public RocksDBStateBackend(URI checkpointDataUri)
                    throws IOException

Creates a new RocksDBStateBackend that stores its checkpoint data in the file system and location defined by the given URI.

A state backend that stores checkpoints in HDFS or S3 must specify the file system host and port in the URI, or have the Hadoop configuration that describes the file system (host / high-availability group / possibly credentials) either referenced from the Flink config, or included in the classpath.

Parameters:

checkpointDataUri - The URI describing the filesystem and path to the checkpoint data directory.

Throws:

IOException - Thrown, if no file system can be found for the scheme in the URI.

RocksDBStateBackend

public RocksDBStateBackend(URI checkpointDataUri,
                           boolean enableIncrementalCheckpointing)
                    throws IOException

Creates a new RocksDBStateBackend that stores its checkpoint data in the file system and location defined by the given URI.

A state backend that stores checkpoints in HDFS or S3 must specify the file system host and port in the URI, or have the Hadoop configuration that describes the file system (host / high-availability group / possibly credentials) either referenced from the Flink config, or included in the classpath.

Parameters:

checkpointDataUri - The URI describing the filesystem and path to the checkpoint data directory.

enableIncrementalCheckpointing - True if incremental checkpointing is enabled.

Throws:

IOException - Thrown, if no file system can be found for the scheme in the URI.

RocksDBStateBackend

public RocksDBStateBackend(org.apache.flink.runtime.state.StateBackend checkpointStreamBackend)

Creates a new RocksDBStateBackend that uses the given state backend to store its checkpoint data streams. Typically, one would supply a filesystem or database state backend here where the snapshots from RocksDB would be stored.

The snapshots of the RocksDB state will be stored using the given backend's StateBackend.createCheckpointStorage(JobID).

Parameters:

checkpointStreamBackend - The backend write the checkpoint streams to.

RocksDBStateBackend

public RocksDBStateBackend(org.apache.flink.runtime.state.StateBackend checkpointStreamBackend,
                           org.apache.flink.util.TernaryBoolean enableIncrementalCheckpointing)

Creates a new RocksDBStateBackend that uses the given state backend to store its checkpoint data streams. Typically, one would supply a filesystem or database state backend here where the snapshots from RocksDB would be stored.

The snapshots of the RocksDB state will be stored using the given backend's StateBackend.createCheckpointStorage(JobID).

Parameters:

checkpointStreamBackend - The backend write the checkpoint streams to.

enableIncrementalCheckpointing - True if incremental checkpointing is enabled.

RocksDBStateBackend

@Deprecated
public RocksDBStateBackend(org.apache.flink.runtime.state.AbstractStateBackend checkpointStreamBackend)

Deprecated. Use RocksDBStateBackend(StateBackend) instead.

RocksDBStateBackend

@Deprecated
public RocksDBStateBackend(org.apache.flink.runtime.state.AbstractStateBackend checkpointStreamBackend,
                                       boolean enableIncrementalCheckpointing)

Deprecated. Use RocksDBStateBackend(StateBackend, TernaryBoolean) instead.

Method Detail

configure

public RocksDBStateBackend configure(org.apache.flink.configuration.ReadableConfig config,
                                     ClassLoader classLoader)

Creates a copy of this state backend that uses the values defined in the configuration for fields where that were not yet specified in this state backend.

Specified by:

configure in interface org.apache.flink.runtime.state.ConfigurableStateBackend

Parameters:

config - The configuration.

classLoader - The class loader.

Returns:

The re-configured variant of the state backend

getCheckpointBackend

public org.apache.flink.runtime.state.StateBackend getCheckpointBackend()

Gets the state backend that this RocksDB state backend uses to persist its bytes to.

This RocksDB state backend only implements the RocksDB specific parts, it relies on the 'CheckpointBackend' to persist the checkpoint and savepoint bytes streams.

resolveCheckpoint

public org.apache.flink.runtime.state.CompletedCheckpointStorageLocation resolveCheckpoint(String pointer)
                                                                                    throws IOException

Specified by:

resolveCheckpoint in interface org.apache.flink.runtime.state.StateBackend

Throws:

IOException

createCheckpointStorage

public org.apache.flink.runtime.state.CheckpointStorage createCheckpointStorage(org.apache.flink.api.common.JobID jobId)
                                                                         throws IOException

Specified by:

createCheckpointStorage in interface org.apache.flink.runtime.state.StateBackend

Throws:

IOException

createKeyedStateBackend

public <K> org.apache.flink.runtime.state.AbstractKeyedStateBackend<K> createKeyedStateBackend(org.apache.flink.runtime.execution.Environment env,
                                                                                               org.apache.flink.api.common.JobID jobID,
                                                                                               String operatorIdentifier,
                                                                                               org.apache.flink.api.common.typeutils.TypeSerializer<K> keySerializer,
                                                                                               int numberOfKeyGroups,
                                                                                               org.apache.flink.runtime.state.KeyGroupRange keyGroupRange,
                                                                                               org.apache.flink.runtime.query.TaskKvStateRegistry kvStateRegistry,
                                                                                               org.apache.flink.runtime.state.ttl.TtlTimeProvider ttlTimeProvider,
                                                                                               org.apache.flink.metrics.MetricGroup metricGroup,
                                                                                               @Nonnull
                                                                                               Collection<org.apache.flink.runtime.state.KeyedStateHandle> stateHandles,
                                                                                               org.apache.flink.core.fs.CloseableRegistry cancelStreamRegistry)
                                                                                        throws IOException

Specified by:

createKeyedStateBackend in interface org.apache.flink.runtime.state.StateBackend

Specified by:

createKeyedStateBackend in class org.apache.flink.runtime.state.AbstractStateBackend

Throws:

IOException

createOperatorStateBackend

public org.apache.flink.runtime.state.OperatorStateBackend createOperatorStateBackend(org.apache.flink.runtime.execution.Environment env,
                                                                                      String operatorIdentifier,
                                                                                      @Nonnull
                                                                                      Collection<org.apache.flink.runtime.state.OperatorStateHandle> stateHandles,
                                                                                      org.apache.flink.core.fs.CloseableRegistry cancelStreamRegistry)
                                                                               throws Exception

Specified by:

createOperatorStateBackend in interface org.apache.flink.runtime.state.StateBackend

Specified by:

createOperatorStateBackend in class org.apache.flink.runtime.state.AbstractStateBackend

Throws:

Exception

getMemoryConfiguration

public RocksDBMemoryConfiguration getMemoryConfiguration()

Gets the memory configuration object, which offers settings to control RocksDB's memory usage.

setDbStoragePath

public void setDbStoragePath(String path)

Sets the path where the RocksDB local database files should be stored on the local file system. Setting this path overrides the default behavior, where the files are stored across the configured temp directories.

Passing null to this function restores the default behavior, where the configured temp directories will be used.

Parameters:

path - The path where the local RocksDB database files are stored.

setDbStoragePaths

public void setDbStoragePaths(String... paths)

Sets the directories in which the local RocksDB database puts its files (like SST and metadata files). These directories do not need to be persistent, they can be ephemeral, meaning that they are lost on a machine failure, because state in RocksDB is persisted in checkpoints.

If nothing is configured, these directories default to the TaskManager's local temporary file directories.

Each distinct state will be stored in one path, but when the state backend creates multiple states, they will store their files on different paths.

Passing null to this function restores the default behavior, where the configured temp directories will be used.

Parameters:

paths - The paths across which the local RocksDB database files will be spread.

getDbStoragePaths

public String[] getDbStoragePaths()

Gets the configured local DB storage paths, or null, if none were configured.

Under these directories on the TaskManager, RocksDB stores its SST files and metadata files. These directories do not need to be persistent, they can be ephermeral, meaning that they are lost on a machine failure, because state in RocksDB is persisted in checkpoints.

If nothing is configured, these directories default to the TaskManager's local temporary file directories.

isIncrementalCheckpointsEnabled

public boolean isIncrementalCheckpointsEnabled()

Gets whether incremental checkpoints are enabled for this state backend.

getPriorityQueueStateType

public RocksDBStateBackend.PriorityQueueStateType getPriorityQueueStateType()

Gets the type of the priority queue state. It will fallback to the default value, if it is not explicitly set.

Returns:

The type of the priority queue state.

setPriorityQueueStateType

public void setPriorityQueueStateType(RocksDBStateBackend.PriorityQueueStateType priorityQueueStateType)

Sets the type of the priority queue state. It will fallback to the default value, if it is not explicitly set.

setPredefinedOptions

public void setPredefinedOptions(@Nonnull
                                 PredefinedOptions options)

Sets the predefined options for RocksDB.

If user-configured options within RocksDBConfigurableOptions is set (through flink-conf.yaml) or a user-defined options factory is set (via setRocksDBOptions(RocksDBOptionsFactory)), then the options from the factory are applied on top of the here specified predefined options and customized options.

Parameters:

options - The options to set (must not be null).

getPredefinedOptions

@VisibleForTesting
public PredefinedOptions getPredefinedOptions()

Gets the currently set predefined options for RocksDB. The default options (if nothing was set via setPredefinedOptions(PredefinedOptions)) are PredefinedOptions.DEFAULT.

If user-configured options within RocksDBConfigurableOptions is set (through flink-conf.yaml) of a user-defined options factory is set (via setRocksDBOptions(RocksDBOptionsFactory)), then the options from the factory are applied on top of the predefined and customized options.

Returns:

The currently set predefined options for RocksDB.

setRocksDBOptions

public void setRocksDBOptions(RocksDBOptionsFactory optionsFactory)

Sets Options for the RocksDB instances. Because the options are not serializable and hold native code references, they must be specified through a factory.

The options created by the factory here are applied on top of the pre-defined options profile selected via setPredefinedOptions(PredefinedOptions). If the pre-defined options profile is the default (PredefinedOptions.DEFAULT), then the factory fully controls the RocksDB options.

Parameters:

optionsFactory - The options factory that lazily creates the RocksDB options.

getRocksDBOptions

@Nullable
public RocksDBOptionsFactory getRocksDBOptions()

Gets Options for the RocksDB instances.

The options created by the factory here are applied on top of the pre-defined options profile selected via setPredefinedOptions(PredefinedOptions). If the pre-defined options profile is the default (PredefinedOptions.DEFAULT), then the factory fully controls the RocksDB options.

getNumberOfTransferThreads

public int getNumberOfTransferThreads()

Gets the number of threads used to transfer files while snapshotting/restoring.

setNumberOfTransferThreads

public void setNumberOfTransferThreads(int numberOfTransferThreads)

Sets the number of threads used to transfer files while snapshotting/restoring.

Parameters:

numberOfTransferThreads - The number of threads used to transfer files while snapshotting/restoring.

getNumberOfTransferingThreads

@Deprecated
public int getNumberOfTransferingThreads()

Deprecated. Typo in method name. Use getNumberOfTransferThreads() instead.

setNumberOfTransferingThreads

@Deprecated
public void setNumberOfTransferingThreads(int numberOfTransferingThreads)

Deprecated. Typo in method name. Use setNumberOfTransferThreads(int) instead.

getWriteBatchSize

public long getWriteBatchSize()

Gets the max batch size will be used in RocksDBWriteBatchWrapper.

setWriteBatchSize

public void setWriteBatchSize(long writeBatchSize)

Sets the max batch size will be used in RocksDBWriteBatchWrapper, no positive value will disable memory size controller, just use item count controller.

Parameters:

writeBatchSize - The size will used to be used in RocksDBWriteBatchWrapper.

toString

public String toString()

Overrides:

toString in class Object