spark-instrumented-optimizer/README.md
Douglas R Colkitt 8fc5cb6285 [SPARK-28473][DOC] Stylistic consistency of build command in README
## What changes were proposed in this pull request?

Change the format of the build command in the README to start with a `./` prefix

    ./build/mvn -DskipTests clean package

This increases stylistic consistency across the README- all the other commands have a `./` prefix. Having a visible `./` prefix also makes it clear to the user that the shell command requires the current working directory to be at the repository root.

## How was this patch tested?

README.md was reviewed both in raw markdown and in the Github rendered landing page for stylistic consistency.

Closes #25231 from Mister-Meeseeks/master.

Lead-authored-by: Douglas R Colkitt <douglas.colkitt@gmail.com>
Co-authored-by: Mister-Meeseeks <douglas.colkitt@gmail.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
2019-07-23 16:29:46 -07:00

110 lines
4.6 KiB
Markdown

# Apache Spark
Spark is a unified analytics engine for large-scale data processing. 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 Structured Streaming for stream processing.
<https://spark.apache.org/>
[![Jenkins Build](https://amplab.cs.berkeley.edu/jenkins/job/spark-master-test-sbt-hadoop-2.7/badge/icon)](https://amplab.cs.berkeley.edu/jenkins/job/spark-master-test-sbt-hadoop-2.7)
[![AppVeyor Build](https://img.shields.io/appveyor/ci/ApacheSoftwareFoundation/spark/master.svg?style=plastic&logo=appveyor)](https://ci.appveyor.com/project/ApacheSoftwareFoundation/spark)
[![PySpark Coverage](https://img.shields.io/badge/dynamic/xml.svg?label=pyspark%20coverage&url=https%3A%2F%2Fspark-test.github.io%2Fpyspark-coverage-site&query=%2Fhtml%2Fbody%2Fdiv%5B1%5D%2Fdiv%2Fh1%2Fspan&colorB=brightgreen&style=plastic)](https://spark-test.github.io/pyspark-coverage-site)
## Online Documentation
You can find the latest Spark documentation, including a programming
guide, on the [project web page](https://spark.apache.org/documentation.html).
This README file only contains basic setup instructions.
## Building Spark
Spark is built using [Apache Maven](https://maven.apache.org/).
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"](https://cwiki.apache.org/confluence/display/MAVEN/Parallel+builds+in+Maven+3).
More detailed documentation is available from the project site, at
["Building Spark"](https://spark.apache.org/docs/latest/building-spark.html).
For general development tips, including info on developing Spark using an IDE, see ["Useful Developer Tools"](https://spark.apache.org/developer-tools.html).
## 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 1,000,000,000:
scala> spark.range(1000 * 1000 * 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 1,000,000,000:
>>> spark.range(1000 * 1000 * 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](#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](https://spark.apache.org/developer-tools.html#individual-tests).
There is also a Kubernetes integration test, see resource-managers/kubernetes/integration-tests/README.md
## 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 and Enabling YARN"](https://spark.apache.org/docs/latest/building-spark.html#specifying-the-hadoop-version-and-enabling-yarn)
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](https://spark.apache.org/docs/latest/configuration.html)
in the online documentation for an overview on how to configure Spark.
## Contributing
Please review the [Contribution to Spark guide](https://spark.apache.org/contributing.html)
for information on how to get started contributing to the project.