bc167a2a53
## What changes were proposed in this pull request? Now since we have migrated to Kryo-3.0.0 in https://issues.apache.org/jira/browse/SPARK-11416, we can gives users option to use unsafe SerDer. It can turned by setting `spark.kryo.useUnsafe` to `true` ## How was this patch tested? Ran existing tests ``` Benchmark Kryo Unsafe vs safe Serialization: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative ------------------------------------------------------------------------------------------------ basicTypes: Int unsafe:true 160 / 178 98.5 10.1 1.0X basicTypes: Long unsafe:true 210 / 218 74.9 13.4 0.8X basicTypes: Float unsafe:true 203 / 213 77.5 12.9 0.8X basicTypes: Double unsafe:true 226 / 235 69.5 14.4 0.7X Array: Int unsafe:true 1087 / 1101 14.5 69.1 0.1X Array: Long unsafe:true 2758 / 2844 5.7 175.4 0.1X Array: Float unsafe:true 1511 / 1552 10.4 96.1 0.1X Array: Double unsafe:true 2942 / 2972 5.3 187.0 0.1X Map of string->Double unsafe:true 2645 / 2739 5.9 168.2 0.1X basicTypes: Int unsafe:false 211 / 218 74.7 13.4 0.8X basicTypes: Long unsafe:false 247 / 253 63.6 15.7 0.6X basicTypes: Float unsafe:false 211 / 216 74.5 13.4 0.8X basicTypes: Double unsafe:false 227 / 233 69.2 14.4 0.7X Array: Int unsafe:false 3012 / 3032 5.2 191.5 0.1X Array: Long unsafe:false 4463 / 4515 3.5 283.8 0.0X Array: Float unsafe:false 2788 / 2868 5.6 177.2 0.1X Array: Double unsafe:false 3558 / 3752 4.4 226.2 0.0X Map of string->Double unsafe:false 2806 / 2933 5.6 178.4 0.1X ``` Author: Sandeep Singh <sandeep@techaddict.me> Author: Sandeep Singh <sandeep@origamilogic.com> Closes #12913 from techaddict/SPARK-928. |
||
---|---|---|
.github | ||
assembly | ||
bin | ||
build | ||
common | ||
conf | ||
core | ||
data | ||
dev | ||
docs | ||
examples | ||
external | ||
graphx | ||
launcher | ||
licenses | ||
mesos | ||
mllib | ||
mllib-local | ||
project | ||
python | ||
R | ||
repl | ||
sbin | ||
sql | ||
streaming | ||
tools | ||
yarn | ||
.gitattributes | ||
.gitignore | ||
.travis.yml | ||
appveyor.yml | ||
CONTRIBUTING.md | ||
LICENSE | ||
NOTICE | ||
pom.xml | ||
README.md | ||
scalastyle-config.xml |
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.
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.)
You can build Spark using more than one thread by using the -T option with Maven, see "Parallel builds in Maven 3". 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.
## Contributing
Please review the Contribution to Spark wiki for information on how to get started contributing to the project.