Apache Spark - A unified analytics engine for large-scale data processing
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Joseph K. Bradley dc0c4490a1 [SPARK-4789] [SPARK-4942] [SPARK-5031] [mllib] Standardize ML Prediction APIs
This is part (1a) of the updates from the design doc in [https://docs.google.com/document/d/1BH9el33kBX8JiDdgUJXdLW14CA2qhTCWIG46eXZVoJs]

**UPDATE**: Most of the APIs are being kept private[spark] to allow further discussion.  Here is a list of changes which are public:
* new output columns: rawPrediction, probabilities
  * The “score” column is now called “rawPrediction”
* Classifiers now provide numClasses
* Params.get and .set are now protected instead of private[ml].
* ParamMap now has a size method.
* new classes: LinearRegression, LinearRegressionModel
* LogisticRegression now has an intercept.

### Sketch of APIs (most of which are private[spark] for now)

Abstract classes for learning algorithms (+ corresponding Model abstractions):
* Classifier (+ ClassificationModel)
* ProbabilisticClassifier (+ ProbabilisticClassificationModel)
* Regressor (+ RegressionModel)
* Predictor (+ PredictionModel)
* *For all of these*:
 * There is no strongly typed training-time API.
 * There is a strongly typed test-time (prediction) API which helps developers implement new algorithms.

Concrete classes: learning algorithms
* LinearRegression
* LogisticRegression (updated to use new abstract classes)
 * Also, removed "score" in favor of "probability" output column.  Changed BinaryClassificationEvaluator to match. (SPARK-5031)

Other updates:
* params.scala: Changed Params.set/get to be protected instead of private[ml]
 * This was needed for the example of defining a class from outside of the MLlib namespace.
* VectorUDT: Will later change from private[spark] to public.
 * This is needed for outside users to write their own validateAndTransformSchema() methods using vectors.
 * Also, added equals() method.f
* SPARK-4942 : ML Transformers should allow output cols to be turned on,off
 * Update validateAndTransformSchema
 * Update transform
* (Updated examples, test suites according to other changes)

New examples:
* DeveloperApiExample.scala (example of defining algorithm from outside of the MLlib namespace)
 * Added Java version too

Test Suites:
* LinearRegressionSuite
* LogisticRegressionSuite
* + Java versions of above suites

CC: mengxr  etrain  shivaram

Author: Joseph K. Bradley <joseph@databricks.com>

Closes #3637 from jkbradley/ml-api-part1 and squashes the following commits:

405bfb8 [Joseph K. Bradley] Last edits based on code review.  Small cleanups
fec348a [Joseph K. Bradley] Added JavaDeveloperApiExample.java and fixed other issues: Made developer API private[spark] for now. Added constructors Java can understand to specialized Param types.
8316d5e [Joseph K. Bradley] fixes after rebasing on master
fc62406 [Joseph K. Bradley] fixed test suites after last commit
bcb9549 [Joseph K. Bradley] Fixed issues after rebasing from master (after move from SchemaRDD to DataFrame)
9872424 [Joseph K. Bradley] fixed JavaLinearRegressionSuite.java Java sql api
f542997 [Joseph K. Bradley] Added MIMA excludes for VectorUDT (now public), and added DeveloperApi annotation to it
216d199 [Joseph K. Bradley] fixed after sql datatypes PR got merged
f549e34 [Joseph K. Bradley] Updates based on code review.  Major ones are: * Created weakly typed Predictor.train() method which is called by fit() so that developers do not have to call schema validation or copy parameters. * Made Predictor.featuresDataType have a default value of VectorUDT.   * NOTE: This could be dangerous since the FeaturesType type parameter cannot have a default value.
343e7bd [Joseph K. Bradley] added blanket mima exclude for ml package
82f340b [Joseph K. Bradley] Fixed bug in LogisticRegression (introduced in this PR).  Fixed Java suites
0a16da9 [Joseph K. Bradley] Fixed Linear/Logistic RegressionSuites
c3c8da5 [Joseph K. Bradley] small cleanup
934f97b [Joseph K. Bradley] Fixed bugs from previous commit.
1c61723 [Joseph K. Bradley] * Made ProbabilisticClassificationModel into a subclass of ClassificationModel.  Also introduced ProbabilisticClassifier.  * This was to support output column “probabilityCol” in transform().
4e2f711 [Joseph K. Bradley] rat fix
bc654e1 [Joseph K. Bradley] Added spark.ml LinearRegressionSuite
8d13233 [Joseph K. Bradley] Added methods: * Classifier: batch predictRaw() * Predictor: train() without paramMap ProbabilisticClassificationModel.predictProbabilities() * Java versions of all above batch methods + others
1680905 [Joseph K. Bradley] Added JavaLabeledPointSuite.java for spark.ml, and added constructor to LabeledPoint which defaults weight to 1.0
adbe50a [Joseph K. Bradley] * fixed LinearRegression train() to use embedded paramMap * added Predictor.predict(RDD[Vector]) method * updated Linear/LogisticRegressionSuites
58802e3 [Joseph K. Bradley] added train() to Predictor subclasses which does not take a ParamMap.
57d54ab [Joseph K. Bradley] * Changed semantics of Predictor.train() to merge the given paramMap with the embedded paramMap. * remove threshold_internal from logreg * Added Predictor.copy() * Extended LogisticRegressionSuite
e433872 [Joseph K. Bradley] Updated docs.  Added LabeledPointSuite to spark.ml
54b7b31 [Joseph K. Bradley] Fixed issue with logreg threshold being set correctly
0617d61 [Joseph K. Bradley] Fixed bug from last commit (sorting paramMap by parameter names in toString).  Fixed bug in persisting logreg data.  Added threshold_internal to logreg for faster test-time prediction (avoiding map lookup).
601e792 [Joseph K. Bradley] Modified ParamMap to sort parameters in toString.  Cleaned up classes in class hierarchy, before implementing tests and examples.
d705e87 [Joseph K. Bradley] Added LinearRegression and Regressor back from ml-api branch
52f4fde [Joseph K. Bradley] removing everything except for simple class hierarchy for classification
d35bb5d [Joseph K. Bradley] fixed compilation issues, but have not added tests yet
bfade12 [Joseph K. Bradley] Added lots of classes for new ML API:
2015-02-05 23:43:47 -08:00
assembly [SPARK-4809] Rework Guava library shading. 2015-01-28 00:29:29 -08:00
bagel [SPARK-4048] Enhance and extend hadoop-provided profile. 2015-01-08 17:15:13 -08:00
bin [SPARK-5341] Use maven coordinates as dependencies in spark-shell and spark-submit 2015-02-03 22:39:17 -08:00
build [SPARK-5474][Build]curl should support URL redirection in build/mvn 2015-02-05 12:03:13 -08:00
conf [SPARK-5422] Add support for sending Graphite metrics via UDP 2015-01-31 23:41:05 -08:00
core SPARK-5557: Explicitly include servlet API in dependencies. 2015-02-05 18:14:54 -08:00
data/mllib SPARK-2363. Clean MLlib's sample data files 2014-07-13 19:27:43 -07:00
dev [SPARK-5474][Build]curl should support URL redirection in build/mvn 2015-02-05 12:03:13 -08:00
docker [SPARK-1342] Scala 2.10.4 2014-04-01 18:35:50 -07:00
docs [Branch-1.3] [DOC] doc fix for date 2015-02-05 12:42:27 -08:00
ec2 [SPARK-5434] [EC2] Preserve spaces in EC2 path 2015-01-28 12:56:03 -08:00
examples [SPARK-4789] [SPARK-4942] [SPARK-5031] [mllib] Standardize ML Prediction APIs 2015-02-05 23:43:47 -08:00
external [SPARK-4707][STREAMING] Reliable Kafka Receiver can lose data if the blo... 2015-02-04 14:20:44 -08:00
extras [SPARK-5155] Build fails with spark-ganglia-lgpl profile 2015-02-01 17:53:56 -08:00
graphx [SPARK-4795][Core] Redesign the "primitive type => Writable" implicit APIs to make them be activated automatically 2015-02-03 20:17:12 -08:00
mllib [SPARK-4789] [SPARK-4942] [SPARK-5031] [mllib] Standardize ML Prediction APIs 2015-02-05 23:43:47 -08:00
network [SPARK-3996]: Shade Jetty in Spark deliverables 2015-02-01 21:13:57 -08:00
project [SPARK-4789] [SPARK-4942] [SPARK-5031] [mllib] Standardize ML Prediction APIs 2015-02-05 23:43:47 -08:00
python [SPARK-5182] [SPARK-5528] [SPARK-5509] [SPARK-3575] [SQL] Parquet data source improvements 2015-02-05 15:29:56 -08:00
repl [SPARK-5612][SQL] Move DataFrame implicit functions into SQLContext.implicits. 2015-02-04 23:44:34 -08:00
sbin [SPARK-5176] The thrift server does not support cluster mode 2015-02-01 17:57:31 -08:00
sbt Adde LICENSE Header to build/mvn, build/sbt and sbt/sbt 2014-12-29 10:48:53 -08:00
sql [SPARK-5639][SQL] Support DataFrame.renameColumn. 2015-02-05 23:02:40 -08:00
streaming [Minor] Fix incorrect warning log 2015-02-04 00:52:41 -08:00
tools SPARK-4159 [CORE] Maven build doesn't run JUnit test suites 2015-01-06 12:02:08 -08:00
yarn SPARK-3996: Add jetty servlet and continuations. 2015-02-02 21:01:36 -08:00
.gitattributes [SPARK-3870] EOL character enforcement 2014-10-31 12:39:52 -07:00
.gitignore [SPARK-4501][Core] - Create build/mvn to automatically download maven/zinc/scalac 2014-12-27 13:26:38 -08:00
.rat-excludes [HOTFIX] Fix RAT exclusion for known_translations file 2014-12-16 23:00:25 -08:00
CONTRIBUTING.md [Docs] minor grammar fix 2014-09-17 12:33:09 -07:00
LICENSE SPARK-3926 [CORE] Reopened: result of JavaRDD collectAsMap() is not serializable 2014-12-08 16:13:03 -08:00
make-distribution.sh [SPARK-5188][BUILD] make-distribution.sh should support curl, not only wget to get Tachyon 2015-01-28 12:43:22 -08:00
NOTICE SPARK-1827. LICENSE and NOTICE files need a refresh to contain transitive dependency info 2014-05-14 09:38:33 -07:00
pom.xml Revert "SPARK-5607: Update to Kryo 2.24.0 to avoid including objenesis 1.2." 2015-02-05 18:36:48 -08:00
README.md [Docs] Fix Building Spark link text 2015-02-02 12:33:49 -08:00
scalastyle-config.xml [Core] Upgrading ScalaStyle version to 0.5 and removing SparkSpaceAfterCommentStartChecker. 2014-10-16 02:05:44 -04:00
tox.ini [SPARK-3073] [PySpark] use external sort in sortBy() and sortByKey() 2014-08-26 16:57:40 -07:00

Apache Spark

Spark is a fast and general cluster computing system for Big Data. It provides high-level APIs in Scala, Java, and Python, and an optimized engine that supports general computation graphs for data analysis. It also supports a rich set of higher-level tools including Spark SQL for SQL and structured data processing, MLlib for machine learning, GraphX for graph processing, and Spark Streaming for stream processing.

http://spark.apache.org/

Online Documentation

You can find the latest Spark documentation, including a programming guide, on the project web page and project wiki. This README file only contains basic setup instructions.

Building Spark

Spark is built using Apache Maven. To build Spark and its example programs, run:

mvn -DskipTests clean package

(You do not need to do this if you downloaded a pre-built package.) More detailed documentation is available from the project site, at "Building Spark".

Interactive Scala Shell

The easiest way to start using Spark is through the Scala shell:

./bin/spark-shell

Try the following command, which should return 1000:

scala> sc.parallelize(1 to 1000).count()

Interactive Python Shell

Alternatively, if you prefer Python, you can use the Python shell:

./bin/pyspark

And run the following command, which should also return 1000:

>>> sc.parallelize(range(1000)).count()

Example Programs

Spark also comes with several sample programs in the examples directory. To run one of them, use ./bin/run-example <class> [params]. For example:

./bin/run-example SparkPi

will run the Pi example locally.

You can set the MASTER environment variable when running examples to submit examples to a cluster. This can be a mesos:// or spark:// URL, "yarn-cluster" or "yarn-client" to run on YARN, and "local" to run locally with one thread, or "local[N]" to run locally with N threads. You can also use an abbreviated class name if the class is in the examples package. For instance:

MASTER=spark://host:7077 ./bin/run-example SparkPi

Many of the example programs print usage help if no params are given.

Running Tests

Testing first requires building Spark. Once Spark is built, tests can be run using:

./dev/run-tests

Please see the guidance on how to run all automated tests.

A Note About Hadoop Versions

Spark uses the Hadoop core library to talk to HDFS and other Hadoop-supported storage systems. Because the protocols have changed in different versions of Hadoop, you must build Spark against the same version that your cluster runs.

Please refer to the build documentation at "Specifying the Hadoop Version" for detailed guidance on building for a particular distribution of Hadoop, including building for particular Hive and Hive Thriftserver distributions. See also "Third Party Hadoop Distributions" for guidance on building a Spark application that works with a particular distribution.

Configuration

Please refer to the Configuration guide in the online documentation for an overview on how to configure Spark.