Apache Spark - A unified analytics engine for large-scale data processing
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Josh Rosen 0c33c7b4a6 [SPARK-7858] [SQL] Use output schema, not relation schema, for data source input conversion
In `DataSourceStrategy.createPhysicalRDD`, we use the relation schema as the target schema for converting incoming rows into Catalyst rows.  However, we should be using the output schema instead, since our scan might return a subset of the relation's columns.

This patch incorporates #6414 by liancheng, which fixes an issue in `SimpleTestRelation` that prevented this bug from being caught by our old tests:

> In `SimpleTextRelation`, we specified `needsConversion` to `true`, indicating that values produced by this testing relation should be of Scala types, and need to be converted to Catalyst types when necessary. However, we also used `Cast` to convert strings to expected data types. And `Cast` always produces values of Catalyst types, thus no conversion is done at all. This PR makes `SimpleTextRelation` produce Scala values so that data conversion code paths can be properly tested.

Closes #5986.

Author: Josh Rosen <joshrosen@databricks.com>
Author: Cheng Lian <lian@databricks.com>
Author: Cheng Lian <liancheng@users.noreply.github.com>

Closes #6400 from JoshRosen/SPARK-7858 and squashes the following commits:

e71c866 [Josh Rosen] Re-fix bug so that the tests pass again
56b13e5 [Josh Rosen] Add regression test to hadoopFsRelationSuites
2169a0f [Josh Rosen] Remove use of SpecificMutableRow and BufferedIterator
6cd7366 [Josh Rosen] Fix SPARK-7858 by using output types for conversion.
5a00e66 [Josh Rosen] Add assertions in order to reproduce SPARK-7858
8ba195c [Cheng Lian] Merge 9968fba9979287aaa1f141ba18bfb9d4c116a3b3 into 61664732b2
9968fba [Cheng Lian] Tests the data type conversion code paths
2015-05-26 20:24:35 -07:00
assembly [SPARK-6869] [PYSPARK] Add pyspark archives path to PYTHONPATH 2015-05-08 08:44:46 -05:00
bagel [SPARK-6758]block the right jetty package in log 2015-04-09 17:44:08 -04:00
bin Limit help option regex 2015-05-01 19:26:55 +01:00
build SPARK-5856: In Maven build script, launch Zinc with more memory 2015-02-17 10:10:01 -08:00
conf [SPARK-7811] Fix typo on slf4j configuration on metrics.properties.tem… 2015-05-24 21:48:27 +01:00
core [SPARK-7864] [UI] Do not kill innocent stages from visualization 2015-05-26 16:31:34 -07:00
data/mllib [SPARK-7574] [ML] [DOC] User guide for OneVsRest 2015-05-22 13:18:08 -07:00
dev [SPARK-7832] [Build] Always run SQL tests in master build. 2015-05-25 18:23:58 -07:00
docker [SPARK-2691] [MESOS] Support for Mesos DockerInfo 2015-05-01 18:41:22 -07:00
docs [SPARK-7883] [DOCS] [MLLIB] Fixing broken trainImplicit Scala example in MLlib Collaborative Filtering documentation. 2015-05-26 18:08:57 -07:00
ec2 [SPARK-3674] YARN support in Spark EC2 2015-05-26 15:01:27 -07:00
examples Close HBaseAdmin at the end of HBaseTest 2015-05-25 08:19:42 +01:00
external [SPARK-7621] [STREAMING] Report Kafka errors to StreamingListeners 2015-05-18 18:13:29 -07:00
extras [SPARK-7838] [STREAMING] Set scope for kinesis stream 2015-05-22 23:05:54 -07:00
graphx [SPARK-5854] personalized page rank 2015-05-01 11:55:43 -07:00
launcher [MINOR] Avoid passing the PermGenSize option to IBM JVMs. 2015-05-13 21:00:12 +01:00
mllib [SPARK-7748] [MLLIB] Graduate spark.ml from alpha 2015-05-26 15:51:31 -07:00
network [SPARK-7726] Fix Scaladoc false errors 2015-05-19 12:14:48 -07:00
project [SPARK-7805] [SQL] Move SQLTestUtils.scala and ParquetTest.scala to src/test 2015-05-24 09:51:37 -07:00
python [SPARK-7339] [PYSPARK] PySpark shuffle spill memory sometimes are not correct 2015-05-26 08:35:39 -07:00
R [SPARK-6811] Copy SparkR lib in make-distribution.sh 2015-05-23 00:04:01 -07:00
repl [SPARK-7726] Fix Scaladoc false errors 2015-05-19 12:14:48 -07:00
sbin [SPARK-5412] [DEPLOY] Cannot bind Master to a specific hostname as per the documentation 2015-05-15 11:30:19 -07:00
sbt Adde LICENSE Header to build/mvn, build/sbt and sbt/sbt 2014-12-29 10:48:53 -08:00
sql [SPARK-7858] [SQL] Use output schema, not relation schema, for data source input conversion 2015-05-26 20:24:35 -07:00
streaming [SPARK-7777][Streaming] Handle the case when there is no block in a batch 2015-05-23 02:11:17 -07:00
tools [SPARK-4550] In sort-based shuffle, store map outputs in serialized form 2015-04-30 23:14:14 -07:00
unsafe [SPARK-7800] isDefined should not marked too early in putNewKey 2015-05-21 23:12:00 +01:00
yarn [SPARK-6602] [CORE] Remove some places in core that calling SparkEnv.actorSystem 2015-05-26 15:28:49 -07:00
.gitattributes [SPARK-3870] EOL character enforcement 2014-10-31 12:39:52 -07:00
.gitignore [MINOR] Ignore python/lib/pyspark.zip 2015-05-08 14:06:02 -07:00
.rat-excludes [WEBUI] Remove debug feature for vis.js 2015-05-08 14:06:37 -07:00
CONTRIBUTING.md [SPARK-6889] [DOCS] CONTRIBUTING.md updates to accompany contribution doc updates 2015-04-21 22:34:31 -07:00
LICENSE [BUILD] update jblas dependency version to 1.2.4 2015-05-16 18:17:48 +01:00
make-distribution.sh [HOTFIX] Copy SparkR lib if it exists in make-distribution 2015-05-23 12:28:16 -07:00
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-7042] [BUILD] use the standard akka artifacts with hadoop-2.x" 2015-05-26 10:05:13 -07:00
README.md [MINOR] [DOCS] Fix the link to test building info on the wiki 2015-05-12 00:25:43 +01:00
scalastyle-config.xml [SPARK-6428] Turn on explicit type checking for public methods. 2015-04-03 01:25:02 -07:00
tox.ini [SPARK-7427] [PYSPARK] Make sharedParams match in Scala, Python 2015-05-10 19:18:32 -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 tests for a module, or individual 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.