Building Spark
- Setting up Maven’s Memory Usage
- Specifying the Hadoop Version
- Building With Hive and JDBC Support
- Building for Scala 2.11
- Spark Tests in Maven
- Continuous Compilation
- Building Spark with IntelliJ IDEA or Eclipse
- Building Spark Debian Packages
- Running Java 8 Test Suites
- Building for PySpark on YARN
- Packaging without Hadoop Dependencies for YARN
- Building with SBT
- Testing with SBT
- Speeding up Compilation with Zinc
Building Spark using Maven requires Maven 3.0.4 or newer and Java 6+.
Note: Building Spark with Java 7 or later can create JAR files that may not be readable with early versions of Java 6, due to the large number of files in the JAR archive. Build with Java 6 if this is an issue for your deployment.
Setting up Maven’s Memory Usage
You’ll need to configure Maven to use more memory than usual by setting MAVEN_OPTS
. We recommend the following settings:
export MAVEN_OPTS="-Xmx2g -XX:MaxPermSize=512M -XX:ReservedCodeCacheSize=512m"
If you don’t run this, you may see errors like the following:
[INFO] Compiling 203 Scala sources and 9 Java sources to /Users/me/Development/spark/core/target/scala-2.10/classes...
[ERROR] PermGen space -> [Help 1]
[INFO] Compiling 203 Scala sources and 9 Java sources to /Users/me/Development/spark/core/target/scala-2.10/classes...
[ERROR] Java heap space -> [Help 1]
You can fix this by setting the MAVEN_OPTS
variable as discussed before.
Note: For Java 8 and above this step is not required.
Specifying the Hadoop Version
Because HDFS is not protocol-compatible across versions, if you want to read from HDFS, you’ll need to build Spark against the specific HDFS version in your environment. You can do this through the “hadoop.version” property. If unset, Spark will build against Hadoop 1.0.4 by default. Note that certain build profiles are required for particular Hadoop versions:
Hadoop version | Profile required |
---|---|
0.23.x | hadoop-0.23 |
1.x to 2.1.x | (none) |
2.2.x | hadoop-2.2 |
2.3.x | hadoop-2.3 |
2.4.x | hadoop-2.4 |
For Apache Hadoop versions 1.x, Cloudera CDH “mr1” distributions, and other Hadoop versions without YARN, use:
# Apache Hadoop 1.2.1
mvn -Dhadoop.version=1.2.1 -DskipTests clean package
# Cloudera CDH 4.2.0 with MapReduce v1
mvn -Dhadoop.version=2.0.0-mr1-cdh4.2.0 -DskipTests clean package
# Apache Hadoop 0.23.x
mvn -Phadoop-0.23 -Dhadoop.version=0.23.7 -DskipTests clean package
For Apache Hadoop 2.x, 0.23.x, Cloudera CDH, and other Hadoop versions with YARN, you can enable the “yarn-alpha” or “yarn” profile and optionally set the “yarn.version” property if it is different from “hadoop.version”. The additional build profile required depends on the YARN version:
YARN version | Profile required |
---|---|
0.23.x to 2.1.x | yarn-alpha (Deprecated.) |
2.2.x and later | yarn |
Note: Support for YARN-alpha API’s will be removed in Spark 1.3 (see SPARK-3445).
Examples:
# Apache Hadoop 2.0.5-alpha
mvn -Pyarn-alpha -Dhadoop.version=2.0.5-alpha -DskipTests clean package
# Cloudera CDH 4.2.0
mvn -Pyarn-alpha -Dhadoop.version=2.0.0-cdh4.2.0 -DskipTests clean package
# Apache Hadoop 0.23.x
mvn -Pyarn-alpha -Phadoop-0.23 -Dhadoop.version=0.23.7 -DskipTests clean package
# Apache Hadoop 2.2.X
mvn -Pyarn -Phadoop-2.2 -Dhadoop.version=2.2.0 -DskipTests clean package
# Apache Hadoop 2.3.X
mvn -Pyarn -Phadoop-2.3 -Dhadoop.version=2.3.0 -DskipTests clean package
# Apache Hadoop 2.4.X or 2.5.X
mvn -Pyarn -Phadoop-2.4 -Dhadoop.version=VERSION -DskipTests clean package
Versions of Hadoop after 2.5.X may or may not work with the -Phadoop-2.4 profile (they were
released after this version of Spark).
# Different versions of HDFS and YARN.
mvn -Pyarn-alpha -Phadoop-2.3 -Dhadoop.version=2.3.0 -Dyarn.version=0.23.7 -DskipTests clean package
Building With Hive and JDBC Support
To enable Hive integration for Spark SQL along with its JDBC server and CLI,
add the -Phive
and Phive-thriftserver
profiles to your existing build options.
By default Spark will build with Hive 0.13.1 bindings. You can also build for
Hive 0.12.0 using the -Phive-0.12.0
profile.
# Apache Hadoop 2.4.X with Hive 13 support
mvn -Pyarn -Phadoop-2.4 -Dhadoop.version=2.4.0 -Phive -Phive-thriftserver -DskipTests clean package
# Apache Hadoop 2.4.X with Hive 12 support
mvn -Pyarn -Phadoop-2.4 -Dhadoop.version=2.4.0 -Phive -Phive-0.12.0 -Phive-thriftserver -DskipTests clean package
Building for Scala 2.11
To produce a Spark package compiled with Scala 2.11, use the -Dscala-2.11
property:
dev/change-version-to-2.11.sh
mvn -Pyarn -Phadoop-2.4 -Dscala-2.11 -DskipTests clean package
Scala 2.11 support in Spark is experimental and does not support a few features. Specifically, Spark’s external Kafka library and JDBC component are not yet supported in Scala 2.11 builds.
Spark Tests in Maven
Tests are run by default via the ScalaTest Maven plugin.
Some of the tests require Spark to be packaged first, so always run mvn package
with -DskipTests
the first time. The following is an example of a correct (build, test) sequence:
mvn -Pyarn -Phadoop-2.3 -DskipTests -Phive -Phive-thriftserver clean package
mvn -Pyarn -Phadoop-2.3 -Phive -Phive-thriftserver test
The ScalaTest plugin also supports running only a specific test suite as follows:
mvn -Dhadoop.version=... -DwildcardSuites=org.apache.spark.repl.ReplSuite test
Continuous Compilation
We use the scala-maven-plugin which supports incremental and continuous compilation. E.g.
mvn scala:cc
should run continuous compilation (i.e. wait for changes). However, this has not been tested
extensively. A couple of gotchas to note:
* it only scans the paths src/main
and src/test
(see
docs), so it will only work
from within certain submodules that have that structure.
* you’ll typically need to run mvn install
from the project root for compilation within
specific submodules to work; this is because submodules that depend on other submodules do so via
the spark-parent
module).
Thus, the full flow for running continuous-compilation of the core
submodule may look more like:
$ mvn install
$ cd core
$ mvn scala:cc
Building Spark with IntelliJ IDEA or Eclipse
For help in setting up IntelliJ IDEA or Eclipse for Spark development, and troubleshooting, refer to the wiki page for IDE setup.
Building Spark Debian Packages
The Maven build includes support for building a Debian package containing the assembly ‘fat-jar’, PySpark, and the necessary scripts and configuration files. This can be created by specifying the following:
mvn -Pdeb -DskipTests clean package
The debian package can then be found under assembly/target. We added the short commit hash to the file name so that we can distinguish individual packages built for SNAPSHOT versions.
Running Java 8 Test Suites
Running only Java 8 tests and nothing else.
mvn install -DskipTests -Pjava8-tests
Java 8 tests are run when -Pjava8-tests
profile is enabled, they will run in spite of -DskipTests
.
For these tests to run your system must have a JDK 8 installation.
If you have JDK 8 installed but it is not the system default, you can set JAVA_HOME to point to JDK 8 before running the tests.
Building for PySpark on YARN
PySpark on YARN is only supported if the jar is built with Maven. Further, there is a known problem with building this assembly jar on Red Hat based operating systems (see SPARK-1753). If you wish to run PySpark on a YARN cluster with Red Hat installed, we recommend that you build the jar elsewhere, then ship it over to the cluster. We are investigating the exact cause for this.
Packaging without Hadoop Dependencies for YARN
The assembly jar produced by mvn package
will, by default, include all of Spark’s dependencies, including Hadoop and some of its ecosystem projects. On YARN deployments, this causes multiple versions of these to appear on executor classpaths: the version packaged in the Spark assembly and the version on each node, included with yarn.application.classpath. The hadoop-provided
profile builds the assembly without including Hadoop-ecosystem projects, like ZooKeeper and Hadoop itself.
Building with SBT
Maven is the official recommendation for packaging Spark, and is the “build of reference”. But SBT is supported for day-to-day development since it can provide much faster iterative compilation. More advanced developers may wish to use SBT.
The SBT build is derived from the Maven POM files, and so the same Maven profiles and variables can be set to control the SBT build. For example:
sbt/sbt -Pyarn -Phadoop-2.3 assembly
Testing with SBT
Some of the tests require Spark to be packaged first, so always run sbt/sbt assembly
the first time. The following is an example of a correct (build, test) sequence:
sbt/sbt -Pyarn -Phadoop-2.3 -Phive -Phive-thriftserver assembly
sbt/sbt -Pyarn -Phadoop-2.3 -Phive -Phive-thriftserver test
To run only a specific test suite as follows:
sbt/sbt -Pyarn -Phadoop-2.3 -Phive -Phive-thriftserver "test-only org.apache.spark.repl.ReplSuite"
To run test suites of a specific sub project as follows:
sbt/sbt -Pyarn -Phadoop-2.3 -Phive -Phive-thriftserver core/test
Speeding up Compilation with Zinc
Zinc is a long-running server version of SBT’s incremental
compiler. When run locally as a background process, it speeds up builds of Scala-based projects
like Spark. Developers who regularly recompile Spark with Maven will be the most interested in
Zinc. The project site gives instructions for building and running zinc
; OS X users can
install it using brew install zinc
.