org.apache.hadoop.chukwa.datacollection.adaptor

Class DirTailingAdaptor

java.lang.Object

org.apache.hadoop.chukwa.datacollection.adaptor.AbstractAdaptor

org.apache.hadoop.chukwa.datacollection.adaptor.DirTailingAdaptor

All Implemented Interfaces:

Runnable, Adaptor

Direct Known Subclasses:

RegExDirTailingAdaptor

public class DirTailingAdaptor
extends AbstractAdaptor
implements Runnable

Explore a whole directory hierarchy, looking for files to tail. DirTailingAdaptor will not try to start tailing a file more than once, if the file hasn't been modified in the interim. Offset param is used to track last finished scan. Mandatory first parameter is a directory with an optional unix style file filter. Mandatory second parameter is the name of an adaptor to start. If the specified directory does not exist, the DirTailer will continue running, and will start tailing if the directory is later created.

Constructor Summary

Constructors

Constructor and Description
DirTailingAdaptor()

Method Summary

Modifier and Type	Method and Description
String	getCurrentStatus() Return the adaptor's state Should not include class name or byte offset, which are written by caller.
String	parseArgs(String status)
void	run()
long	shutdown(AdaptorShutdownPolicy shutdownPolicy) Signals this adaptor to come to an orderly stop.
void	start(long offset)

Methods inherited from class org.apache.hadoop.chukwa.datacollection.adaptor.AbstractAdaptor

deregisterAndStop, getType, hardStop, parseArgs, shutdown, start

Methods inherited from class java.lang.Object

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

Constructor Detail

DirTailingAdaptor

public DirTailingAdaptor()

Method Detail

start

public void start(long offset)
           throws AdaptorException

Specified by:

start in class AbstractAdaptor

Throws:

AdaptorException

run

public void run()

Specified by:

run in interface Runnable

getCurrentStatus

public String getCurrentStatus()

Description copied from interface: Adaptor

Return the adaptor's state Should not include class name or byte offset, which are written by caller. The datatype should, however, be written by this method.

Specified by:

getCurrentStatus in interface Adaptor

Returns:

the adaptor state as a string

parseArgs

public String parseArgs(String status)

Specified by:

parseArgs in class AbstractAdaptor

shutdown

public long shutdown(AdaptorShutdownPolicy shutdownPolicy)
              throws AdaptorException

Description copied from interface: Adaptor

Signals this adaptor to come to an orderly stop. The adaptor ought to push out all the data it can before exiting depending of the shutdown policy

Specified by:

shutdown in interface Adaptor

Parameters:

shutdownPolicy - is defined as forcefully or gracefully

Returns:

the logical offset at which the adaptor was when the method return

Throws:

AdaptorException - Exception on shutdown