Apache Spark - A unified analytics engine for large-scale data processing
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Andrew Or b3ffac5178 [SPARK-10983] Unified memory manager
This patch unifies the memory management of the storage and execution regions such that either side can borrow memory from each other. When memory pressure arises, storage will be evicted in favor of execution. To avoid regressions in cases where storage is crucial, we dynamically allocate a fraction of space for storage that execution cannot evict. Several configurations are introduced:

- **spark.memory.fraction (default 0.75)**: ​fraction of the heap space used for execution and storage. The lower this is, the more frequently spills and cached data eviction occur. The purpose of this config is to set aside memory for internal metadata, user data structures, and imprecise size estimation in the case of sparse, unusually large records.

- **spark.memory.storageFraction (default 0.5)**: size of the storage region within the space set aside by `s​park.memory.fraction`. ​Cached data may only be evicted if total storage exceeds this region.

- **spark.memory.useLegacyMode (default false)**: whether to use the memory management that existed in Spark 1.5 and before. This is mainly for backward compatibility.

For a detailed description of the design, see [SPARK-10000](https://issues.apache.org/jira/browse/SPARK-10000). This patch builds on top of the `MemoryManager` interface introduced in #9000.

Author: Andrew Or <andrew@databricks.com>

Closes #9084 from andrewor14/unified-memory-manager.
2015-10-13 13:49:59 -07:00
assembly Update version to 1.6.0-SNAPSHOT. 2015-09-15 00:54:20 -07:00
bagel [SPARK-10300] [BUILD] [TESTS] Add support for test tags in run-tests.py. 2015-10-07 14:11:21 -07:00
bin [SPARK-9284] [TESTS] Allow all tests to run without an assembly. 2015-08-28 12:33:40 -07:00
build [SPARK-10952] Only add hive to classpath if HIVE_HOME is set. 2015-10-07 09:54:02 -07:00
conf [SPARK-10718] [BUILD] Update License on conf files and corresponding excludes file update 2015-09-22 11:03:21 +01:00
core [SPARK-10983] Unified memory manager 2015-10-13 13:49:59 -07:00
data/mllib [MLLIB] [DOC] Seed fix in mllib naive bayes example 2015-07-18 10:12:48 -07:00
dev [SPARK-10300] [BUILD] [TESTS] Add support for test tags in run-tests.py. 2015-10-07 14:11:21 -07:00
docker [SPARK-10398] [DOCS] Migrate Spark download page to use new lua mirroring scripts 2015-09-01 20:06:01 +01:00
docs [SPARK-10983] Unified memory manager 2015-10-13 13:49:59 -07:00
ec2 Add 1.5 to master branch EC2 scripts 2015-09-10 13:43:13 -07:00
examples [SPARK-9715] [ML] Store numFeatures in all ML PredictionModel types 2015-09-23 15:00:52 -07:00
external [SPARK-11019] [STREAMING] [FLUME] Gracefully shutdown Flume receiver th… 2015-10-08 18:50:27 -07:00
extras [SPARK-10300] [BUILD] [TESTS] Add support for test tags in run-tests.py. 2015-10-07 14:11:21 -07:00
graphx [SPARK-10300] [BUILD] [TESTS] Add support for test tags in run-tests.py. 2015-10-07 14:11:21 -07:00
launcher [SPARK-8673] [LAUNCHER] API and infrastructure for communicating with child apps. 2015-10-09 15:28:09 -05:00
licenses [SPARK-10833] [BUILD] Inline, organize BSD/MIT licenses in LICENSE 2015-09-28 22:56:43 -04:00
mllib [SPARK-7402] [ML] JSON SerDe for standard param types 2015-10-13 13:24:10 -07:00
network [SPARK-10300] [BUILD] [TESTS] Add support for test tags in run-tests.py. 2015-10-07 14:11:21 -07:00
project [SPARK-10810] [SPARK-10902] [SQL] Improve session management in SQL 2015-10-08 17:34:24 -07:00
python [PYTHON] [MINOR] List modules in PySpark tests when given bad name 2015-10-13 12:03:46 -07:00
R [SPARK-10913] [SPARKR] attach() function support 2015-10-13 10:21:07 -07:00
repl [SPARK-10300] [BUILD] [TESTS] Add support for test tags in run-tests.py. 2015-10-07 14:11:21 -07:00
sbin [SPARK-10317] [CORE] Compatibility between history server script and functionality 2015-10-02 15:26:11 -07:00
sbt Adde LICENSE Header to build/mvn, build/sbt and sbt/sbt 2014-12-29 10:48:53 -08:00
sql [SPARK-10983] Unified memory manager 2015-10-13 13:49:59 -07:00
streaming [SPARK-10772] [STREAMING] [SCALA] NullPointerException when transform function in DStream returns NULL 2015-10-10 11:36:18 +01:00
tags [SPARK-10300] [BUILD] [TESTS] Add support for test tags in run-tests.py. 2015-10-07 14:11:21 -07:00
tools Update version to 1.6.0-SNAPSHOT. 2015-09-15 00:54:20 -07:00
unsafe [SPARK-10990] [SPARK-11018] [SQL] improve unrolling of complex types 2015-10-12 21:12:59 -07:00
yarn [SPARK-11026] [YARN] spark.yarn.user.classpath.first does work for 'spark-submit --jars hdfs://user/foo.jar' 2015-10-13 08:29:47 -05:00
.gitattributes [SPARK-3870] EOL character enforcement 2014-10-31 12:39:52 -07:00
.gitignore [SPARK-8495] [SPARKR] Add a .lintr file to validate the SparkR files and the lint-r script 2015-06-20 16:10:14 -07:00
.rat-excludes [SPARK-10718] [BUILD] Update License on conf files and corresponding excludes file update 2015-09-22 11:03:21 +01:00
CONTRIBUTING.md [SPARK-6889] [DOCS] CONTRIBUTING.md updates to accompany contribution doc updates 2015-04-21 22:34:31 -07:00
LICENSE [SPARK-10833] [BUILD] Inline, organize BSD/MIT licenses in LICENSE 2015-09-28 22:56:43 -04:00
make-distribution.sh [SPARK-10833] [BUILD] Inline, organize BSD/MIT licenses in LICENSE 2015-09-28 22:56:43 -04:00
NOTICE [SPARK-10833] [BUILD] Inline, organize BSD/MIT licenses in LICENSE 2015-09-28 22:56:43 -04:00
pom.xml [SPARK-10300] [BUILD] [TESTS] Add support for test tags in run-tests.py. 2015-10-07 14:11:21 -07:00
pylintrc [SPARK-9116] [SQL] [PYSPARK] support Python only UDT in __main__ 2015-07-29 22:30:49 -07:00
README.md [SPARK-9570] [DOCS] Consistent recommendation for submitting spark apps to YARN, -master yarn --deploy-mode x vs -master yarn-x'. 2015-10-04 09:31:52 +01:00
scalastyle-config.xml [SPARK-10330] Add Scalastyle rule to require use of SparkHadoopUtil JobContext methods 2015-09-12 16:23:55 -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, 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".

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. 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.