Apache Spark - A unified analytics engine for large-scale data processing
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Yuhao Yang 9a0272fbb3 [SPARK-6177][MLlib]Add note in LDA example to remind possible coalesce
JIRA: https://issues.apache.org/jira/browse/SPARK-6177
Add comment to introduce coalesce to LDA example to avoid the possible massive partitions from `sc.textFile`.

sc.textFile will create RDD with one partition for each file, and the possible massive partitions downgrades LDA performance.

Author: Yuhao Yang <hhbyyh@gmail.com>

Closes #4899 from hhbyyh/adjustPartition and squashes the following commits:

a499630 [Yuhao Yang] update comment
9a2d7b6 [Yuhao Yang] move to comment
f7fd5d4 [Yuhao Yang] Merge remote-tracking branch 'upstream/master' into adjustPartition
26a564a [Yuhao Yang] add coalesce to LDAExample
2015-03-10 10:52:21 +00:00
assembly SPARK-6182 [BUILD] spark-parent pom needs to be published for both 2.10 and 2.11 2015-03-05 11:31:48 -08:00
bagel SPARK-6182 [BUILD] spark-parent pom needs to be published for both 2.10 and 2.11 2015-03-05 11:31:48 -08:00
bin [SPARK-5765][Examples]Fixed word split problem in run-example and compute-classpath 2015-02-12 14:44:21 -08:00
build SPARK-5856: In Maven build script, launch Zinc with more memory 2015-02-17 10:10:01 -08:00
conf [Spark-5708] Add Slf4jSink to Spark Metrics 2015-02-24 20:50:16 +00:00
core [SPARK-6194] [SPARK-677] [PySpark] fix memory leak in collect() 2015-03-09 16:24:06 -07:00
data/mllib [SPARK-5939][MLLib] make FPGrowth example app take parameters 2015-02-23 08:47:28 -08:00
dev SPARK-5143 [BUILD] [WIP] spark-network-yarn 2.11 depends on spark-network-shuffle 2.10 2015-03-04 21:00:51 -08:00
docker [SPARK-1342] Scala 2.10.4 2014-04-01 18:35:50 -07:00
docs [SPARK-5310][Doc] Update SQL Programming Guide to include DataFrames. 2015-03-09 16:16:16 -07:00
ec2 [EC2] [SPARK-6188] Instance types can be mislabeled when re-starting cluster with default arguments 2015-03-09 14:16:07 +00:00
examples [SPARK-6177][MLlib]Add note in LDA example to remind possible coalesce 2015-03-10 10:52:21 +00:00
external SPARK-6182 [BUILD] spark-parent pom needs to be published for both 2.10 and 2.11 2015-03-05 11:31:48 -08:00
extras SPARK-6182 [BUILD] spark-parent pom needs to be published for both 2.10 and 2.11 2015-03-05 11:31:48 -08:00
graphx SPARK-6182 [BUILD] spark-parent pom needs to be published for both 2.10 and 2.11 2015-03-05 11:31:48 -08:00
mllib [SPARK-6090][MLLIB] add a basic BinaryClassificationMetrics to PySpark/MLlib 2015-03-05 11:50:09 -08:00
network [SPARK-6178][Shuffle] Removed unused imports 2015-03-06 14:43:09 +00:00
project [SPARK-5310][SQL] Fixes to Docs and Datasources API 2015-03-02 22:14:08 -08:00
python [SPARK-6194] [SPARK-677] [PySpark] fix memory leak in collect() 2015-03-09 16:24:06 -07:00
repl [Docs] Replace references to SchemaRDD with DataFrame 2015-03-09 13:29:19 -07:00
sbin [Minor]fix the wrong description 2015-03-07 12:35:26 +00:00
sbt Adde LICENSE Header to build/mvn, build/sbt and sbt/sbt 2014-12-29 10:48:53 -08:00
sql [SQL] Make Strategies a public developer API 2015-03-05 14:50:25 -08:00
streaming [Minor] Resolve sbt warnings: postfix operator second should be enabled 2015-03-06 13:20:20 +00:00
tools SPARK-6182 [BUILD] spark-parent pom needs to be published for both 2.10 and 2.11 2015-03-05 11:31:48 -08:00
yarn SPARK-6182 [BUILD] spark-parent pom needs to be published for both 2.10 and 2.11 2015-03-05 11:31:48 -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 [SPARK-5778] throw if nonexistent metrics config file provided 2015-02-17 10:57:16 -08:00
CONTRIBUTING.md [Docs] minor grammar fix 2014-09-17 12:33:09 -07:00
LICENSE SPARK-5984: Fix TimSort bug causes ArrayOutOfBoundsException 2015-02-28 18:55:34 -08:00
make-distribution.sh SPARK-5747: Fix wordsplitting bugs in make-distribution.sh 2015-02-12 14:52:38 -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-6205 [CORE] UISeleniumSuite fails for Hadoop 2.x test with NoClassDefFoundError 2015-03-08 14:09:40 +00:00
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.