org.apache.crunch

Interface Pipeline

All Known Implementing Classes:

DistributedPipeline, MemPipeline, MRPipeline, SparkPipeline

public interface Pipeline

Manages the state of a pipeline execution.

Method Summary

Methods

Modifier and Type	Method and Description
<T> void	cache(PCollection<T> pcollection, CachingOptions options) Caches the given PCollection so that it will be processed at most once during pipeline execution.
void	cleanup(boolean force) Cleans up any artifacts created as a result of running the pipeline.
<K,V> PTable<K,V>	create(Iterable<Pair<K,V>> contents, PTableType<K,V> ptype) Creates a PTable containing the values found in the given Iterable using an implementation-specific distribution mechanism.
<K,V> PTable<K,V>	create(Iterable<Pair<K,V>> contents, PTableType<K,V> ptype, CreateOptions options) Creates a PTable containing the values found in the given Iterable using an implementation-specific distribution mechanism.
<T> PCollection<T>	create(Iterable<T> contents, PType<T> ptype) Creates a PCollection containing the values found in the given Iterable using an implementation-specific distribution mechanism.
<T> PCollection<T>	create(Iterable<T> contents, PType<T> ptype, CreateOptions options) Creates a PCollection containing the values found in the given Iterable using an implementation-specific distribution mechanism.
PipelineResult	done() Run any remaining jobs required to generate outputs and then clean up any intermediate data files that were created in this run or previous calls to run.
<T> PCollection<T>	emptyPCollection(PType<T> ptype) Creates an empty PCollection of the given PType.
<K,V> PTable<K,V>	emptyPTable(PTableType<K,V> ptype) Creates an empty PTable of the given PTable Type.
void	enableDebug() Turn on debug logging for jobs that are run from this pipeline.
org.apache.hadoop.conf.Configuration	getConfiguration() Returns the Configuration instance associated with this pipeline.
String	getName() Returns the name of this pipeline.
<T> Iterable<T>	materialize(PCollection<T> pcollection) Create the given PCollection and read the data it contains into the returned Collection instance for client use.
<T> PCollection<T>	read(Source<T> source) Converts the given Source into a PCollection that is available to jobs run using this Pipeline instance.
<T> PCollection<T>	read(Source<T> source, String named) Converts the given Source into a PCollection that is available to jobs run using this Pipeline instance.
<K,V> PTable<K,V>	read(TableSource<K,V> tableSource) A version of the read method for TableSource instances that map to PTables.
<K,V> PTable<K,V>	read(TableSource<K,V> tableSource, String named) A version of the read method for TableSource instances that map to PTables.
PCollection<String>	readTextFile(String pathName) A convenience method for reading a text file.
PipelineResult	run() Constructs and executes a series of MapReduce jobs in order to write data to the output targets.
PipelineExecution	runAsync() Constructs and starts a series of MapReduce jobs in order ot write data to the output targets, but returns a ListenableFuture to allow clients to control job execution.
<Output> Output	sequentialDo(PipelineCallable<Output> pipelineCallable) Executes the given PipelineCallable on the client after the Targets that the PipelineCallable depends on (if any) have been created by other pipeline processing steps.
void	setConfiguration(org.apache.hadoop.conf.Configuration conf) Set the Configuration to use with this pipeline.
<S> PCollection<S>	union(List<PCollection<S>> collections)
<K,V> PTable<K,V>	unionTables(List<PTable<K,V>> tables)
void	write(PCollection<?> collection, Target target) Write the given collection to the given target on the next pipeline run.
void	write(PCollection<?> collection, Target target, Target.WriteMode writeMode) Write the contents of the PCollection to the given Target, using the storage format specified by the target and the given WriteMode for cases where the referenced Target already exists.
<T> void	writeTextFile(PCollection<T> collection, String pathName) A convenience method for writing a text file.

Method Detail

setConfiguration

void setConfiguration(org.apache.hadoop.conf.Configuration conf)

Set the Configuration to use with this pipeline.

getName

String getName()

Returns the name of this pipeline.

Returns:

Name of the pipeline

getConfiguration

org.apache.hadoop.conf.Configuration getConfiguration()

Returns the Configuration instance associated with this pipeline.

read

<T> PCollection<T> read(Source<T> source)

Converts the given Source into a PCollection that is available to jobs run using this Pipeline instance.

Parameters:

source - The source of data

Returns:

A PCollection that references the given source

read

<T> PCollection<T> read(Source<T> source,
                      String named)

Converts the given Source into a PCollection that is available to jobs run using this Pipeline instance.

Parameters:

source - The source of data

named - A name for the returned PCollection

Returns:

A PCollection that references the given source

read

<K,V> PTable<K,V> read(TableSource<K,V> tableSource)

A version of the read method for TableSource instances that map to PTables.

Parameters:

tableSource - The source of the data

Returns:

A PTable that references the given source

read

<K,V> PTable<K,V> read(TableSource<K,V> tableSource,
                     String named)

A version of the read method for TableSource instances that map to PTables.

Parameters:

tableSource - The source of the data

named - A name for the returned PTable

Returns:

A PTable that references the given source

write

void write(PCollection<?> collection,
         Target target)

Write the given collection to the given target on the next pipeline run. The system will check to see if the target's location already exists using the WriteMode.DEFAULT rule for the given Target.

Parameters:

collection - The collection

target - The output target

write

void write(PCollection<?> collection,
         Target target,
         Target.WriteMode writeMode)

Write the contents of the PCollection to the given Target, using the storage format specified by the target and the given WriteMode for cases where the referenced Target already exists.

Parameters:

collection - The collection

target - The target to write to

writeMode - The strategy to use for handling existing outputs

materialize

<T> Iterable<T> materialize(PCollection<T> pcollection)

Create the given PCollection and read the data it contains into the returned Collection instance for client use.

Parameters:

pcollection - The PCollection to materialize

Returns:

the data from the PCollection as a read-only Collection

cache

<T> void cache(PCollection<T> pcollection,
             CachingOptions options)

Caches the given PCollection so that it will be processed at most once during pipeline execution.

Parameters:

pcollection - The PCollection to cache

options - The options for how the cached data is stored

emptyPCollection

<T> PCollection<T> emptyPCollection(PType<T> ptype)

Creates an empty PCollection of the given PType.

Parameters:

ptype - The PType of the empty PCollection

Returns:

A valid PCollection with no contents

emptyPTable

<K,V> PTable<K,V> emptyPTable(PTableType<K,V> ptype)

Creates an empty PTable of the given PTable Type.

Parameters:

ptype - The PTableType of the empty PTable

Returns:

A valid PTable with no contents

create

<T> PCollection<T> create(Iterable<T> contents,
                        PType<T> ptype)

Creates a PCollection containing the values found in the given Iterable using an implementation-specific distribution mechanism.

Parameters:

contents - The values the new PCollection will contain

ptype - The PType of the PCollection

Returns:

A PCollection that contains the given values

create

<T> PCollection<T> create(Iterable<T> contents,
                        PType<T> ptype,
                        CreateOptions options)

Creates a PCollection containing the values found in the given Iterable using an implementation-specific distribution mechanism.

Parameters:

contents - The values the new PCollection will contain

ptype - The PType of the PCollection

options - Additional options, such as the name or desired parallelism of the PCollection

Returns:

A PCollection that contains the given values

create

<K,V> PTable<K,V> create(Iterable<Pair<K,V>> contents,
                       PTableType<K,V> ptype)

Creates a PTable containing the values found in the given Iterable using an implementation-specific distribution mechanism.

Parameters:

contents - The values the new PTable will contain

ptype - The PTableType of the PTable

Returns:

A PTable that contains the given values

create

<K,V> PTable<K,V> create(Iterable<Pair<K,V>> contents,
                       PTableType<K,V> ptype,
                       CreateOptions options)

Creates a PTable containing the values found in the given Iterable using an implementation-specific distribution mechanism.

Parameters:

contents - The values the new PTable will contain

ptype - The PTableType of the PTable

options - Additional options, such as the name or desired parallelism of the PTable

Returns:

A PTable that contains the given values

union

<S> PCollection<S> union(List<PCollection<S>> collections)

unionTables

<K,V> PTable<K,V> unionTables(List<PTable<K,V>> tables)

sequentialDo

<Output> Output sequentialDo(PipelineCallable<Output> pipelineCallable)

Executes the given PipelineCallable on the client after the Targets that the PipelineCallable depends on (if any) have been created by other pipeline processing steps.

Type Parameters:

Output - The return type of the PipelineCallable

Parameters:

pipelineCallable - The sequential logic to execute

Returns:

The result of executing the PipelineCallable

run

PipelineResult run()

Constructs and executes a series of MapReduce jobs in order to write data to the output targets.

runAsync

PipelineExecution runAsync()

Constructs and starts a series of MapReduce jobs in order ot write data to the output targets, but returns a ListenableFuture to allow clients to control job execution.

Returns:

done

PipelineResult done()

Run any remaining jobs required to generate outputs and then clean up any intermediate data files that were created in this run or previous calls to run.

cleanup

void cleanup(boolean force)

Cleans up any artifacts created as a result of running the pipeline.

Parameters:

force - forces the cleanup even if all targets of the pipeline have not been completed.

readTextFile

PCollection<String> readTextFile(String pathName)

A convenience method for reading a text file.

writeTextFile

<T> void writeTextFile(PCollection<T> collection,
                     String pathName)

A convenience method for writing a text file.

enableDebug

void enableDebug()

Turn on debug logging for jobs that are run from this pipeline.