Apache Spark - A unified analytics engine for large-scale data processing
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Wenchen Fan 32407bfd2b [SPARK-9899] [SQL] log warning for direct output committer with speculation enabled
This is a follow-up of https://github.com/apache/spark/pull/8317.

When speculation is enabled, there may be multiply tasks writing to the same path. Generally it's OK as we will write to a temporary directory first and only one task can commit the temporary directory to target path.

However, when we use direct output committer, tasks will write data to target path directly without temporary directory. This causes problems like corrupted data. Please see [PR comment](https://github.com/apache/spark/pull/8191#issuecomment-131598385) for more details.

Unfortunately, we don't have a simple flag to tell if a output committer will write to temporary directory or not, so for safety, we have to disable any customized output committer when `speculation` is true.

Author: Wenchen Fan <cloud0fan@outlook.com>

Closes #8687 from cloud-fan/direct-committer.
2015-09-14 11:51:39 -07:00
assembly [SPARK-7801] [BUILD] Updating versions to SPARK 1.5.0 2015-06-03 10:11:27 -07:00
bagel [SPARK-10222] [GRAPHX] [DOCS] More thoroughly deprecate Bagel in favor of GraphX 2015-09-13 08:36:46 +01:00
bin [SPARK-9284] [TESTS] Allow all tests to run without an assembly. 2015-08-28 12:33:40 -07:00
build [SPARK-9633] [BUILD] SBT download locations outdated; need an update 2015-08-06 23:43:52 +01:00
conf [SPARK-8118] [SQL] Redirects Parquet JUL logger via SLF4J 2015-08-18 20:15:33 +08:00
core [SPARK-9899] [SQL] log warning for direct output committer with speculation enabled 2015-09-14 11:51:39 -07:00
data/mllib [MLLIB] [DOC] Seed fix in mllib naive bayes example 2015-07-18 10:12:48 -07:00
dev [SPARK-10497] [BUILD] [TRIVIAL] Handle both locations for JIRAError with python-jira 2015-09-10 16:42:12 +02:00
docker [SPARK-10398] [DOCS] Migrate Spark download page to use new lua mirroring scripts 2015-09-01 20:06:01 +01:00
docs [SPARK-10222] [GRAPHX] [DOCS] More thoroughly deprecate Bagel in favor of GraphX 2015-09-13 08:36:46 +01:00
ec2 Add 1.5 to master branch EC2 scripts 2015-09-10 13:43:13 -07:00
examples [SPARK-10330] Add Scalastyle rule to require use of SparkHadoopUtil JobContext methods 2015-09-12 16:23:55 -07:00
external [SPARK-10547] [TEST] Streamline / improve style of Java API tests 2015-09-12 10:40:10 +01:00
extras [SPARK-10547] [TEST] Streamline / improve style of Java API tests 2015-09-12 10:40:10 +01:00
graphx [SPARK-10227] fatal warnings with sbt on Scala 2.11 2015-09-09 09:57:58 +01:00
launcher [SPARK-9284] [TESTS] Allow all tests to run without an assembly. 2015-08-28 12:33:40 -07:00
mllib [SPARK-9720] [ML] Identifiable types need UID in toString methods 2015-09-14 09:18:46 +01:00
network [SPARK-10004] [SHUFFLE] Perform auth checks when clients read shuffle data. 2015-09-02 12:53:24 -07:00
project [SPARK-10556] Remove explicit Scala version for sbt project build files 2015-09-11 13:06:14 +01:00
python [SPARK-6548] Adding stddev to DataFrame functions 2015-09-12 10:17:15 -07:00
R [SPARK-6548] Adding stddev to DataFrame functions 2015-09-12 10:17:15 -07:00
repl [SPARK-10227] fatal warnings with sbt on Scala 2.11 2015-09-09 09:57:58 +01:00
sbin [SPARK-8064] [SQL] Build against Hive 1.2.1 2015-08-03 15:24:42 -07:00
sbt Adde LICENSE Header to build/mvn, build/sbt and sbt/sbt 2014-12-29 10:48:53 -08:00
sql [SPARK-9899] [SQL] log warning for direct output committer with speculation enabled 2015-09-14 11:51:39 -07:00
streaming [SPARK-10547] [TEST] Streamline / improve style of Java API tests 2015-09-12 10:40:10 +01:00
tools [SPARK-9613] [CORE] Ban use of JavaConversions and migrate all existing uses to JavaConverters 2015-08-25 12:33:13 +01:00
unsafe [SPARK-10351] [SQL] Fixes UTF8String.fromAddress to handle off-heap memory 2015-08-30 23:12:56 -07:00
yarn [SPARK-8167] Make tasks that fail from YARN preemption not fail job 2015-09-10 11:58:54 -07:00
.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-9340] [SQL] Fixes converting unannotated Parquet lists 2015-08-11 12:46:33 +08:00
CONTRIBUTING.md [SPARK-6889] [DOCS] CONTRIBUTING.md updates to accompany contribution doc updates 2015-04-21 22:34:31 -07:00
LICENSE [SPARK-8709] Exclude hadoop-client's mockito-all dependency 2015-06-29 14:07:55 -07:00
make-distribution.sh [SPARK-9199] [CORE] Upgrade Tachyon version from 0.7.0 -> 0.7.1. 2015-08-17 08:28:16 +01:00
NOTICE SPARK-1827. LICENSE and NOTICE files need a refresh to contain transitive dependency info 2014-05-14 09:38:33 -07:00
pom.xml [SPARK-10222] [GRAPHX] [DOCS] More thoroughly deprecate Bagel in favor of GraphX 2015-09-13 08:36:46 +01:00
pylintrc [SPARK-9116] [SQL] [PYSPARK] support Python only UDT in __main__ 2015-07-29 22:30:49 -07:00
README.md [DOC] Added R to the list of languages with "high-level API" support in the… 2015-09-08 14:36:34 +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-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 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.