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Marcelo Vanzin authored
Currently, when Spark launches the Yarn AM, the process will use
the local Hadoop configuration on the node where the AM launches,
if one is present. A more correct approach is to use the same
configuration used to launch the Spark job, since the user may
have made modifications (such as adding app-specific configs).

The approach taken here is to use the distributed cache to make
all files in the Hadoop configuration directory available to the
AM. This is a little overkill since only the AM needs them (the
executors use the broadcast Hadoop configuration from the driver),
but is the easier approach.

Even though only a few files in that directory may end up being
used, all of them are uploaded. This allows supporting use cases
such as when auxiliary configuration files are used for SSL
configuration, or when uploading a Hive configuration directory.
Not all of these may be reflected in a o.a.h.conf.Configuration object,
but may be needed when a driver in cluster mode instantiates, for
example, a HiveConf object instead.

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #4142 from vanzin/SPARK-2669 and squashes the following commits:

f5434b9 [Marcelo Vanzin] Merge branch 'master' into SPARK-2669
013f0fb [Marcelo Vanzin] Review feedback.
f693152 [Marcelo Vanzin] Le sigh.
ed45b7d [Marcelo Vanzin] Zip all config files and upload them as an archive.
5927b6b [Marcelo Vanzin] Merge branch 'master' into SPARK-2669
cbb9fb3 [Marcelo Vanzin] Remove stale test.
e3e58d0 [Marcelo Vanzin] Merge branch 'master' into SPARK-2669
e3d0613 [Marcelo Vanzin] Review feedback.
34bdbd8 [Marcelo Vanzin] Fix test.
022a688 [Marcelo Vanzin] Merge branch 'master' into SPARK-2669
a77ddd5 [Marcelo Vanzin] Merge branch 'master' into SPARK-2669
79221c7 [Marcelo Vanzin] [SPARK-2669] [yarn] Distribute client configuration to AM.
50ab8a65
History

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.