flink-instrumentation/workspace/flink-1.4.1-instrumented/flink-1.4.1/flink-runtime/src/main/java/org/apache/flink/runtime/state/StateBackend.java
/**
	 * Creates a new {@link AbstractKeyedStateBackend} that is responsible for holding <b>keyed state</b>
	 * and checkpointing it.
	 * 
	 * <p><i>Keyed State</i> is state where each value is bound to a key.
	 * 
	 * @param env
	 * @param jobID
	 * @param operatorIdentifier
	 * @param keySerializer
	 * @param numberOfKeyGroups
	 * @param keyGroupRange
	 * @param kvStateRegistry
	 * 
	 * @param <K> The type of the keys by which the state is organized.
	 *     
	 * @return The Keyed State Backend for the given job, operator, and key group range.
	 * 
	 * @throws Exception This method may forward all exceptions that occur while instantiating the backend.
	 */
Creates a new  AbstractKeyedStateBackend that is responsible for holding keyed state
and checkpointing it.

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



@param  The type of the keys by which the state is organized.

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

@throws Exception This method may forward all exceptions that occur while instantiating the backend.
Creates a new AbstractKeyedStateBackend that is responsible for holding keyed state and checkpointing it . Keyed State is state where each value is bound to a key . @param The type of the keys by which the state is organized . @return The Keyed State Backend for the given job operator and key group range . @throws Exception This method may forward all exceptions that occur while instantiating the backend .
<K> AbstractKeyedStateBackend<K> createKeyedStateBackend(
			Environment env,
			JobID jobID,
			String operatorIdentifier,
			TypeSerializer<K> keySerializer,
			int numberOfKeyGroups,
			KeyGroupRange keyGroupRange,
			TaskKvStateRegistry kvStateRegistry) throws Exception;
< K > AbstractKeyedStateBackend < K > createKeyedStateBackend ( Environment env , JobID jobID , String operatorIdentifier , TypeSerializer < K > keySerializer , int numberOfKeyGroups , KeyGroupRange keyGroupRange , TaskKvStateRegistry kvStateRegistry ) throws Exception ;
Creates a new {@link AbstractKeyedStateBackend} that is responsible for holding <b>keyed state</b>
 and checkpointing it.
Creates a new { @link AbstractKeyedStateBackend } that is responsible for holding <b > keyed state< / b > and checkpointing it .