Apache Spark - A unified analytics engine for large-scale data processing
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Josh Rosen d6969ffc0f [SPARK-12817] Add BlockManager.getOrElseUpdate and remove CacheManager
CacheManager directly calls MemoryStore.unrollSafely() and has its own logic for handling graceful fallback to disk when cached data does not fit in memory. However, this logic also exists inside of the MemoryStore itself, so this appears to be unnecessary duplication.

Thanks to the addition of block-level read/write locks in #10705, we can refactor the code to remove the CacheManager and replace it with an atomic `BlockManager.getOrElseUpdate()` method.

This pull request replaces / subsumes #10748.

/cc andrewor14 and nongli for review. Note that this changes the locking semantics of a couple of internal BlockManager methods (`doPut()` and `lockNewBlockForWriting`), so please pay attention to the Scaladoc changes and new test cases for those methods.

Author: Josh Rosen <joshrosen@databricks.com>

Closes #11436 from JoshRosen/remove-cachemanager.
2016-03-02 10:26:47 -08:00
.github [MINOR][MAINTENANCE] Fix typo for the pull request template. 2016-02-24 00:45:31 -08:00
assembly [SPARK-6363][BUILD] Make Scala 2.11 the default Scala version 2016-01-30 00:20:28 -08:00
bin [SPARK-13592][WINDOWS] fix path of spark-submit2.cmd in spark-submit.cmd 2016-03-01 14:37:36 +00:00
build [SPARK-13324][CORE][BUILD] Update plugin, test, example dependencies for 2.x 2016-02-17 19:03:29 -08:00
common [SPARK-13548][BUILD] Move tags and unsafe modules into common 2016-03-01 15:39:13 -08:00
conf [SPARK-13264][DOC] Removed multi-byte characters in spark-env.sh.template 2016-02-11 09:30:36 +00:00
core [SPARK-12817] Add BlockManager.getOrElseUpdate and remove CacheManager 2016-03-02 10:26:47 -08:00
data [SPARK-12247][ML][DOC] Documentation for spark.ml's ALS and collaborative filtering in general 2016-02-16 13:03:28 +00:00
dev Fix run-tests.py typos 2016-03-02 15:32:32 +00:00
docker [SPARK-13189] Cleanup build references to Scala 2.10 2016-02-09 11:56:25 -08:00
docker-integration-tests [SPARK-12941][SQL][MASTER] Spark-SQL JDBC Oracle dialect fails to map string datatypes to Oracle VARCHAR datatype 2016-02-25 22:52:25 -08:00
docs [SPARK-13529][BUILD] Move network/* modules into common/network-* 2016-02-28 17:25:07 -08:00
examples [MINOR][STREAMING] Replace deprecated apply with create in example. 2016-03-02 11:48:23 +00:00
external [SPARK-13069][STREAMING] Add "ask" style store() to ActorReciever 2016-02-25 12:32:24 -08:00
extras [SPARK-13186][STREAMING] migrate away from SynchronizedMap 2016-02-22 09:44:32 +00:00
graphx [MINOR][DOCS] Fix all typos in markdown files of doc and similar patterns in other comments 2016-02-22 09:52:07 +00:00
launcher [SPARK-13529][BUILD] Move network/* modules into common/network-* 2016-02-28 17:25:07 -08:00
licenses [SPARK-10833] [BUILD] Inline, organize BSD/MIT licenses in LICENSE 2015-09-28 22:56:43 -04:00
mllib [SPARK-12811][ML] Estimator for Generalized Linear Models(GLMs) 2016-03-01 08:47:56 -08:00
project [SPARK-13526][SQL] Move SQLContext per-session states to new class 2016-02-27 19:51:28 -08:00
python [SPARK-13008][ML][PYTHON] Put one alg per line in pyspark.ml all lists 2016-03-01 21:26:47 -08:00
R [SPARK-13504] [SPARKR] Add approxQuantile for SparkR 2016-02-25 21:23:41 -08:00
repl [SPARK-13086][SHELL] Use the Scala REPL settings, to enable things like -i file. 2016-02-09 09:05:22 +00:00
sbin [SPARK-13521][BUILD] Remove reference to Tachyon in cluster & release scripts 2016-02-26 22:35:12 -08:00
sbt Adde LICENSE Header to build/mvn, build/sbt and sbt/sbt 2014-12-29 10:48:53 -08:00
sql [SPARK-13609] [SQL] Support Column Pruning for MapPartitions 2016-03-02 09:59:22 -08:00
streaming [SPARK-12817] Add BlockManager.getOrElseUpdate and remove CacheManager 2016-03-02 10:26:47 -08:00
tools [SPARK-6363][BUILD] Make Scala 2.11 the default Scala version 2016-01-30 00:20:28 -08:00
yarn [SPARK-13478][YARN] Use real user when fetching delegation tokens. 2016-02-29 13:01:27 -08:00
.gitattributes [SPARK-3870] EOL character enforcement 2014-10-31 12:39:52 -07:00
.gitignore [SPARK-12735] Consolidate & move spark-ec2 to AMPLab managed repository. 2016-01-09 20:28:20 -08:00
.rat-excludes [SPARK-12790][CORE] Remove HistoryServer old multiple files format 2016-02-01 16:55:21 -08:00
checkstyle-suppressions.xml [SPARK-6990][BUILD] Add Java linting script; fix minor warnings 2015-12-04 12:03:45 -08:00
checkstyle.xml [SPARK-12830] Java style: disallow trailing whitespaces. 2016-01-14 23:33:45 -08:00
CONTRIBUTING.md [SPARK-6889] [DOCS] CONTRIBUTING.md updates to accompany contribution doc updates 2015-04-21 22:34:31 -07:00
LICENSE [SPARK-13189] Cleanup build references to Scala 2.10 2016-02-09 11:56:25 -08:00
make-distribution.sh [SPARK-13529][BUILD] Move network/* modules into common/network-* 2016-02-28 17:25:07 -08:00
NOTICE [SPARK-8725][PROJECT-INFRA] Test modules in topologically-sorted order in dev/run-tests 2016-01-26 14:20:11 -08:00
pom.xml [SPARK-13548][BUILD] Move tags and unsafe modules into common 2016-03-01 15:39:13 -08:00
pylintrc [SPARK-9116] [SQL] [PYSPARK] support Python only UDT in __main__ 2015-07-29 22:30:49 -07:00
README.md Add links howto to setup IDEs for developing spark 2015-12-04 14:43:16 +00:00
scalastyle-config.xml [SPARK-13203] Add scalastyle rule banning use of mutable.SynchronizedBuffer 2016-02-10 10:58:41 +00:00
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, Python, and R, 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 DataFrames, 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:

build/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". For developing Spark using an IDE, see Eclipse and IntelliJ.

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" 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.

Configuration

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