org.apache.pig.impl.streaming
Class ExecutableManager

java.lang.Object
  org.apache.pig.impl.streaming.ExecutableManager

Direct Known Subclasses:

HadoopExecutableManager

public class ExecutableManager
extends Object

ExecutableManager manages an external executable which processes data in a Pig query. The ExecutableManager is responsible for startup/teardown of the external process and also for managing it. It feeds input records to the executable via it's stdin, collects the output records from the stdout and also diagnostic information from the stdout.

Field Summary

protected StreamingCommand	command
protected int	exitCode
protected long	inputBytes
protected long	inputRecords
protected Throwable	outerrThreadsError
protected long	outputBytes
protected long	outputRecords
protected DataOutputStream	stdin

Constructor Summary

ExecutableManager()
Create a new ExecutableManager.

Method Summary

void	close() Close and cleanup the ExecutableManager.
void	configure(POStream stream) Configure and initialize the ExecutableManager.
protected void	exec() Start execution of the external process.
protected void	processError(String error) Workhorse to process the stderr stream of the managed process.
void	run() Start execution of the ExecutableManager.
protected void	setupEnvironment(ProcessBuilder pb) Set up the run-time environment of the managed process.

Methods inherited from class java.lang.Object

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

Field Detail

command

protected StreamingCommand command

exitCode

protected int exitCode

stdin

protected DataOutputStream stdin

inputRecords

protected long inputRecords

inputBytes

protected long inputBytes

outputRecords

protected long outputRecords

outputBytes

protected long outputBytes

outerrThreadsError

protected volatile Throwable outerrThreadsError

Constructor Detail

ExecutableManager

public ExecutableManager()

Create a new ExecutableManager.

Method Detail

configure

public void configure(POStream stream)
               throws IOException,
                      ExecException

Configure and initialize the ExecutableManager.

Parameters:

stream - POStream operator

Throws:

IOException

ExecException

close

public void close()
           throws IOException

Close and cleanup the ExecutableManager.

Throws:

IOException

setupEnvironment

protected void setupEnvironment(ProcessBuilder pb)

Set up the run-time environment of the managed process.

Parameters:

pb - ProcessBuilder used to exec the process

exec

protected void exec()
             throws IOException

Start execution of the external process. This takes care of setting up the environment of the process and also starts ProcessErrorThread to process the stderr of the managed process.

Throws:

IOException

run

public void run()
         throws IOException

Start execution of the ExecutableManager.

Throws:

IOException

processError

protected void processError(String error)

Workhorse to process the stderr stream of the managed process. By default ExecuatbleManager just sends out the received error message to the stderr of itself.

Parameters:

error - error message from the managed process.