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

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. 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.

Field Summary

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

adaptorID, control, dest, type

Constructor Summary

Constructors

Constructor and Description
DirTailingAdaptor()

Method Summary

Methods

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.
void	hardStop() Deprecated.
String	parseArgs(String status) Parse args, return stream name.
void	run()
long	shutdown() Deprecated.
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, start

Methods inherited from class java.lang.Object

clone, equals, finalize, 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)

Description copied from interface: Adaptor

Parse args, return stream name. Do not start running. Return the stream name, given params. The stream name is the part of the Adaptor status that's used to determine uniqueness.

Specified by:

parseArgs in interface Adaptor

Returns:

Stream name as a string, null if params are malformed

shutdown

@Deprecated
public long shutdown()
              throws AdaptorException

Deprecated.

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. This method is synchronous up to 60 seconds

Specified by:

shutdown in interface Adaptor

Returns:

the logical offset at which the adaptor stops

Throws:

AdaptorException

hardStop

@Deprecated
public void hardStop()
              throws AdaptorException

Deprecated.

Description copied from interface: Adaptor

Signals this adaptor to come to an abrupt stop, as quickly as it can. The use case here is "Whups, I didn't mean to start that adaptor tailing a gigabyte file, stop it now". Adaptors might need to do something nontrivial here, e.g., in the case in which they have registered periodic timer interrupts, or use a shared worker thread from which they need to disengage. This method is synchronous: In other words, after shutdown() returns, no new data should be written.

Specified by:

hardStop in interface Adaptor

Throws:

AdaptorException

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

Returns:

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

Throws:

AdaptorException