org.apache.flink.runtime.state

Interface StateBackendFactory<T extends StateBackend>

Type Parameters:

T - The type of the state backend created.

All Known Implementing Classes:

EmbeddedRocksDBStateBackendFactory, FsStateBackendFactory, HashMapStateBackendFactory, MemoryStateBackendFactory, RocksDBStateBackendFactory

@PublicEvolving
public interface StateBackendFactory<T extends StateBackend>

A factory to create a specific state backend. The state backend creation gets a Configuration object that can be used to read further config values.

The state backend factory is typically specified in the configuration to produce a configured state backend.

Method Summary

Modifier and Type	Method and Description
T	createFromConfig(ReadableConfig config, ClassLoader classLoader) Creates the state backend, optionally using the given configuration.

Method Detail

createFromConfig

T createFromConfig(ReadableConfig config,
                   ClassLoader classLoader)
            throws IllegalConfigurationException,
                   IOException

Creates the state backend, optionally using the given configuration.

Parameters:

config - The Flink configuration (loaded by the TaskManager).

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

Returns:

The created state backend.

Throws:

IllegalConfigurationException - If the configuration misses critical values, or specifies invalid values

IOException - If the state backend initialization failed due to an I/O exception