org.apache.flink.api.java

Class LocalEnvironment

java.lang.Object

org.apache.flink.api.java.ExecutionEnvironment

org.apache.flink.api.java.LocalEnvironment

public class LocalEnvironment
extends ExecutionEnvironment

An ExecutionEnvironment that runs the program locally, multi-threaded, in the JVM where the environment is instantiated.

When this environment is instantiated, it uses a default parallelism of 1. The default parallelism can be set via ExecutionEnvironment.setParallelism(int).

Local environments can also be instantiated through ExecutionEnvironment.createLocalEnvironment() and ExecutionEnvironment.createLocalEnvironment(int). The former version will pick a default parallelism equal to the number of hardware contexts in the local machine.

Field Summary

Fields inherited from class org.apache.flink.api.java.ExecutionEnvironment

jobID, lastJobExecutionResult, LOG, sessionTimeout

Constructor Summary

Constructors

Constructor and Description
LocalEnvironment() Creates a new local environment.
LocalEnvironment(Configuration config) Creates a new local environment that configures its local executor with the given configuration.

Method Summary

Methods

Modifier and Type	Method and Description
JobExecutionResult	execute(String jobName) Triggers the program execution.
String	getExecutionPlan() Creates the plan with which the system will execute the program, and returns it as a String using a JSON representation of the execution data flow graph.
void	startNewSession() Starts a new session, discarding the previous data flow and all of its intermediate results.
String	toString()

Methods inherited from class org.apache.flink.api.java.ExecutionEnvironment

addDefaultKryoSerializer, addDefaultKryoSerializer, areExplicitEnvironmentsAllowed, createCollectionsEnvironment, createHadoopInput, createHadoopInput, createInput, createInput, createLocalEnvironment, createLocalEnvironment, createLocalEnvironment, createProgramPlan, createProgramPlan, createProgramPlan, createRemoteEnvironment, createRemoteEnvironment, createRemoteEnvironment, execute, fromCollection, fromCollection, fromCollection, fromCollection, fromElements, fromParallelCollection, fromParallelCollection, generateSequence, getConfig, getExecutionEnvironment, getId, getIdString, getLastJobExecutionResult, getNumberOfExecutionRetries, getParallelism, getSessionTimeout, initializeContextEnvironment, readCsvFile, readFile, readFileOfPrimitives, readFileOfPrimitives, readHadoopFile, readHadoopFile, readHadoopFile, readHadoopFile, readSequenceFile, readTextFile, readTextFile, readTextFileWithValue, readTextFileWithValue, registerCachedFile, registerCachedFile, registerCachedFilesWithPlan, registerType, registerTypeWithKryoSerializer, registerTypeWithKryoSerializer, resetContextEnvironment, setDefaultLocalParallelism, setNumberOfExecutionRetries, setParallelism, setSessionTimeout

Methods inherited from class java.lang.Object

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

Constructor Detail

LocalEnvironment

public LocalEnvironment()

Creates a new local environment.

LocalEnvironment

public LocalEnvironment(Configuration config)

Creates a new local environment that configures its local executor with the given configuration.

Parameters:

config - The configuration used to configure the local executor.

Method Detail

execute

public JobExecutionResult execute(String jobName)
                           throws Exception

Description copied from class: ExecutionEnvironment

Triggers the program execution. The environment will execute all parts of the program that have resulted in a "sink" operation. Sink operations are for example printing results (DataSet.print(), writing results (e.g. DataSet.writeAsText(String), DataSet.write(org.apache.flink.api.common.io.FileOutputFormat, String), or other generic data sinks created with DataSet.output(org.apache.flink.api.common.io.OutputFormat).

The program execution will be logged and displayed with the given job name.

Specified by:

execute in class ExecutionEnvironment

Returns:

The result of the job execution, containing elapsed time and accumulators.

Throws:

Exception - Thrown, if the program executions fails.

getExecutionPlan

public String getExecutionPlan()
                        throws Exception

Description copied from class: ExecutionEnvironment

Creates the plan with which the system will execute the program, and returns it as a String using a JSON representation of the execution data flow graph. Note that this needs to be called, before the plan is executed.

Specified by:

getExecutionPlan in class ExecutionEnvironment

Returns:

The execution plan of the program, as a JSON String.

Throws:

Exception - Thrown, if the compiler could not be instantiated, or the master could not be contacted to retrieve information relevant to the execution planning.

startNewSession

public void startNewSession()
                     throws Exception

Description copied from class: ExecutionEnvironment

Starts a new session, discarding the previous data flow and all of its intermediate results.

Specified by:

startNewSession in class ExecutionEnvironment

Throws:

Exception

toString

public String toString()

Overrides:

toString in class Object