Apache Spark - A unified analytics engine for large-scale data processing
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jbencook fd41eb9574 [SPARK-4860][pyspark][sql] speeding up sample() and takeSample()
This PR modifies the python `SchemaRDD` to use `sample()` and `takeSample()` from Scala instead of the slower python implementations from `rdd.py`. This is worthwhile because the `Row`'s are already serialized as Java objects.

In order to use the faster `takeSample()`, a `takeSampleToPython()` method was implemented in `SchemaRDD.scala` following the pattern of `collectToPython()`.

Author: jbencook <jbenjamincook@gmail.com>
Author: J. Benjamin Cook <jbenjamincook@gmail.com>

Closes #3764 from jbencook/master and squashes the following commits:

6fbc769 [J. Benjamin Cook] [SPARK-4860][pyspark][sql] fixing sloppy indentation for takeSampleToPython() arguments
5170da2 [J. Benjamin Cook] [SPARK-4860][pyspark][sql] fixing typo: from RDD to SchemaRDD
de22f70 [jbencook] [SPARK-4860][pyspark][sql] using sample() method from JavaSchemaRDD
b916442 [jbencook] [SPARK-4860][pyspark][sql] adding sample() to JavaSchemaRDD
020cbdf [jbencook] [SPARK-4860][pyspark][sql] using Scala implementations of `sample()` and `takeSample()`
2014-12-23 17:46:24 -08:00
assembly SPARK-4338. [YARN] Ditch yarn-alpha. 2014-12-09 11:02:43 -08:00
bagel Bumping version to 1.3.0-SNAPSHOT. 2014-11-18 21:24:18 -08:00
bin [SPARK-4831] Do not include SPARK_CLASSPATH if empty 2014-12-19 19:32:46 -08:00
conf [SPARK-4889] update history server example cmds 2014-12-19 13:56:04 -08:00
core [SPARK-4606] Send EOF to child JVM when there's no more data to read. 2014-12-23 16:07:59 -08:00
data/mllib SPARK-2363. Clean MLlib's sample data files 2014-07-13 19:27:43 -07:00
dev [SPARK-4914][Build] Cleans lib_managed before compiling with Hive 0.13.1 2014-12-23 12:54:20 -08:00
docker [SPARK-1342] Scala 2.10.4 2014-04-01 18:35:50 -07:00
docs [SPARK-4931][Yarn][Docs] Fix the format of running-on-yarn.md 2014-12-23 11:18:06 -08:00
ec2 [SPARK-4890] Upgrade Boto to 2.34.0; automatically download Boto from PyPi instead of packaging it 2014-12-19 17:02:37 -08:00
examples [SPARK-4932] Add help comments in Analytics 2014-12-23 12:39:41 -08:00
external fixed spelling errors in documentation 2014-12-14 00:01:16 -08:00
extras Bumping version to 1.3.0-SNAPSHOT. 2014-11-18 21:24:18 -08:00
graphx [SPARK-4620] Add unpersist in Graph and GraphImpl 2014-12-07 19:42:02 -08:00
mllib [SPARK-4907][MLlib] Inconsistent loss and gradient in LeastSquaresGradient compared with R 2014-12-22 16:42:55 -08:00
network [SPARK-4864] Add documentation to Netty-based configs 2014-12-22 13:09:22 -08:00
project [Build] Remove spark-staging-1038 2014-12-19 08:29:38 -08:00
python [SPARK-4860][pyspark][sql] speeding up sample() and takeSample() 2014-12-23 17:46:24 -08:00
repl [SPARK-4472][Shell] Print "Spark context available as sc." only when SparkContext is created... 2014-11-21 00:42:43 -08:00
sbin [SPARK-874] adding a --wait flag 2014-12-09 12:16:19 -08:00
sbt [SPARK-4701] Typo in sbt/sbt 2014-12-03 12:08:00 -08:00
sql [SPARK-4860][pyspark][sql] speeding up sample() and takeSample() 2014-12-23 17:46:24 -08:00
streaming [SPARK-4671][Streaming]Do not replicate streaming block when WAL is enabled 2014-12-23 15:45:53 -08:00
tools Bumping version to 1.3.0-SNAPSHOT. 2014-11-18 21:24:18 -08:00
yarn [SPARK-4730][YARN] Warn against deprecated YARN settings 2014-12-23 14:28:36 -08:00
.gitattributes [SPARK-3870] EOL character enforcement 2014-10-31 12:39:52 -07:00
.gitignore [SPARK-4890] Ignore downloaded EC2 libs 2014-12-23 11:12:16 -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-2192 [BUILD] Examples Data Not in Binary Distribution 2014-12-01 16:31:04 +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 [SPARK-4914][Build] Cleans lib_managed before compiling with Hive 0.13.1 2014-12-23 12:54:20 -08:00
README.md SPARK-971 [DOCS] Link to Confluence wiki from project website / documentation 2014-11-09 17:40:48 -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 with Maven".

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.