org.apache.flink.runtime.state.hashmap

类 HashMapStateBackend

java.lang.Object

org.apache.flink.runtime.state.AbstractStateBackend

org.apache.flink.runtime.state.hashmap.HashMapStateBackend

所有已实现的接口:

Serializable, ConfigurableStateBackend, StateBackend

@PublicEvolving
public class HashMapStateBackend
extends AbstractStateBackend
implements ConfigurableStateBackend

This state backend holds the working state in the memory (JVM heap) of the TaskManagers and checkpoints based on the configured CheckpointStorage.

State Size Considerations

Working state is kept on the TaskManager heap. If a TaskManager executes multiple tasks concurrently (if the TaskManager has multiple slots, or if slot-sharing is used) then the aggregate state of all tasks needs to fit into that TaskManager's memory.

Configuration

As for all state backends, this backend can either be configured within the application (by creating the backend with the respective constructor parameters and setting it on the execution environment) or by specifying it in the Flink configuration.

If the state backend was specified in the application, it may pick up additional configuration parameters from the Flink configuration. For example, if the backend if configured in the application without a default savepoint directory, it will pick up a default savepoint directory specified in the Flink configuration of the running job/cluster. That behavior is implemented via the configure(ReadableConfig, ClassLoader) method.

另请参阅:

序列化表格

嵌套类概要

从接口继承的嵌套类/接口 org.apache.flink.runtime.state.StateBackend

StateBackend.CustomInitializationMetrics, StateBackend.KeyedStateBackendParameters<K>, StateBackend.OperatorStateBackendParameters

字段概要

从类继承的字段 org.apache.flink.runtime.state.AbstractStateBackend

latencyTrackingConfigBuilder

构造器概要

构造器

构造器和说明
HashMapStateBackend() Creates a new state backend.

方法概要

限定符和类型	方法和说明
HashMapStateBackend	configure(org.apache.flink.configuration.ReadableConfig config, ClassLoader classLoader) Creates a variant of the state backend that applies additional configuration parameters.
<K> AbstractKeyedStateBackend<K>	createKeyedStateBackend(StateBackend.KeyedStateBackendParameters<K> parameters) Creates a new CheckpointableKeyedStateBackend that is responsible for holding keyed state and checkpointing it.
OperatorStateBackend	createOperatorStateBackend(StateBackend.OperatorStateBackendParameters parameters) Creates a new OperatorStateBackend that can be used for storing operator state.
boolean	supportsNoClaimRestoreMode() Tells if a state backend supports the RestoreMode.NO_CLAIM mode.
boolean	supportsSavepointFormat(org.apache.flink.core.execution.SavepointFormatType formatType)

从类继承的方法 org.apache.flink.runtime.state.AbstractStateBackend

getCompressionDecorator

从类继承的方法 java.lang.Object

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

从接口继承的方法 org.apache.flink.runtime.state.StateBackend

createAsyncKeyedStateBackend, getName, supportsAsyncKeyedStateBackend, useManagedMemory

构造器详细资料

HashMapStateBackend

public HashMapStateBackend()

Creates a new state backend.

方法详细资料

configure

public HashMapStateBackend configure(org.apache.flink.configuration.ReadableConfig config,
                                     ClassLoader classLoader)
                              throws org.apache.flink.configuration.IllegalConfigurationException

从接口复制的说明: ConfigurableStateBackend

Creates a variant of the state backend that applies additional configuration parameters.

Settings that were directly done on the original state backend object in the application program typically have precedence over setting picked up from the configuration.

If no configuration is applied, or if the method directly applies configuration values to the (mutable) state backend object, this method may return the original state backend object. Otherwise it typically returns a modified copy.

指定者:

configure 在接口中 ConfigurableStateBackend

参数:

config - The configuration to pick the values from.

classLoader - The class loader that should be used to load the state backend.

返回:

A reconfigured state backend.

抛出:

org.apache.flink.configuration.IllegalConfigurationException - Thrown if the configuration contained invalid entries.

supportsNoClaimRestoreMode

public boolean supportsNoClaimRestoreMode()

从接口复制的说明: StateBackend

Tells if a state backend supports the RestoreMode.NO_CLAIM mode.

If a state backend supports NO_CLAIM mode, it should create an independent snapshot when it receives CheckpointType.FULL_CHECKPOINT in Snapshotable.snapshot(long, long, CheckpointStreamFactory, CheckpointOptions).

指定者:

supportsNoClaimRestoreMode 在接口中 StateBackend

返回:

If the state backend supports RestoreMode.NO_CLAIM mode.

supportsSavepointFormat

public boolean supportsSavepointFormat(org.apache.flink.core.execution.SavepointFormatType formatType)

指定者:

supportsSavepointFormat 在接口中 StateBackend

createKeyedStateBackend

public <K> AbstractKeyedStateBackend<K> createKeyedStateBackend(StateBackend.KeyedStateBackendParameters<K> parameters)
                                                         throws IOException

从接口复制的说明: StateBackend

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

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

指定者:

createKeyedStateBackend 在接口中 StateBackend

指定者:

createKeyedStateBackend 在类中 AbstractStateBackend

类型参数:

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

参数:

parameters - The arguments bundle for creating CheckpointableKeyedStateBackend.

返回:

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

抛出:

IOException

createOperatorStateBackend

public OperatorStateBackend createOperatorStateBackend(StateBackend.OperatorStateBackendParameters parameters)
                                                throws BackendBuildingException

从接口复制的说明: 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.

指定者:

createOperatorStateBackend 在接口中 StateBackend

指定者:

createOperatorStateBackend 在类中 AbstractStateBackend

参数:

parameters - The arguments bundle for creating OperatorStateBackend.

返回:

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

抛出:

BackendBuildingException