org.apache.hadoop.chukwa.datacollection.writer.gora

Class GoraWriter

java.lang.Object

org.apache.hadoop.chukwa.datacollection.writer.PipelineableWriter

org.apache.hadoop.chukwa.datacollection.writer.gora.GoraWriter

All Implemented Interfaces:

ChukwaWriter

public class GoraWriter
extends PipelineableWriter

This class leverages Apache Gora as a pipeline writer implementation for mapping Chukwa data chunks and metadata as ChukwaChunk's.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.hadoop.chukwa.datacollection.writer.ChukwaWriter

ChukwaWriter.COMMIT_PENDING, ChukwaWriter.CommitStatus

Field Summary

Fields inherited from interface org.apache.hadoop.chukwa.datacollection.writer.ChukwaWriter

COMMIT_FAIL, COMMIT_OK

Constructor Summary

Constructors

Constructor and Description
GoraWriter() Default constructor for this class.

Method Summary

Modifier and Type	Method and Description
ChukwaWriter.CommitStatus	add(List<Chunk> chunks) Called repeatedly with data that should be serialized.
void	close() If the DataStore instance is not null, we execute a DataStore.flush().
void	init(org.apache.hadoop.conf.Configuration c) DataStore objects are created from a factory.

Methods inherited from class org.apache.hadoop.chukwa.datacollection.writer.PipelineableWriter

setNextStage

Methods inherited from class java.lang.Object

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

Constructor Detail

GoraWriter

public GoraWriter()
           throws WriterException

Default constructor for this class.

Throws:

WriterException - if error writing

Method Detail

init

public void init(org.apache.hadoop.conf.Configuration c)
          throws WriterException

DataStore objects are created from a factory. It is necessary to provide the key and value class. The datastore class parameters is optional, and if not specified it will be read from the gora.properties file.

Parameters:

c - is Chukwa configuration

Throws:

WriterException - if error occurs

See Also:

ChukwaWriter.init(org.apache.hadoop.conf.Configuration)

close

public void close()
           throws WriterException

If the DataStore instance is not null, we execute a DataStore.flush(). This forces the write caches to be flushed. DataStore implementations may optimize their writing by deferring the actual put / delete operations until this moment.

Otherwise, we utilize DataStore.close() which closes the DataStore. This should release any resources held by the implementation, so that the instance is ready for GC. All other DataStore methods cannot be used after this method was called. Subsequent calls of this method are ignored.

Throws:

WriterException - if error writing data

See Also:

ChukwaWriter.close()

add

public ChukwaWriter.CommitStatus add(List<Chunk> chunks)
                              throws WriterException

Description copied from interface: ChukwaWriter

Called repeatedly with data that should be serialized. Subclasses may assume that init() will be called before any calls to add(), and that add() won't be called after close().

Specified by:

add in interface ChukwaWriter

Overrides:

add in class PipelineableWriter

Parameters:

chunks - is a list of data to send

Returns:

CommitStatus

Throws:

WriterException - if error writing data