e0f28e010c
Dealing with [SPARK-4737], the handling of serialization errors should not be the DAGScheduler's responsibility. The task set manager now catches the error and aborts the stage. If the TaskSetManager throws a TaskNotSerializableException, the TaskSchedulerImpl will return an empty list of task descriptions, because no tasks were started. The scheduler should abort the stage gracefully. Note that I'm not too familiar with this part of the codebase and its place in the overall architecture of the Spark stack. If implementing it this way will have any averse side effects please voice that loudly. Author: mcheah <mcheah@palantir.com> Closes #3638 from mccheah/task-set-manager-properly-handle-ser-err and squashes the following commits: 1545984 [mcheah] Some more style fixes from Andrew Or. 5267929 [mcheah] Fixing style suggestions from Andrew Or. dfa145b [mcheah] Fixing style from Josh Rosen's feedback b2a430d [mcheah] Not returning empty seq when a task set cannot be serialized. 94844d7 [mcheah] Fixing compilation error, one brace too many 5f486f4 [mcheah] Adding license header for fake task class bf5e706 [mcheah] Fixing indentation. 097e7a2 [mcheah] [SPARK-4737] Catching task serialization exception in TaskSetManager |
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tox.ini |
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.
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 with Maven".
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.