Building and Testing REEF Java


  • Java Development Kit 7 or 8. Make sure that $JAVA_HOME points to it.
  • Apache Maven 3.3 or newer. Make sure that mvn is in your $PATH and $M2_HOME points to its installation.
  • Protocol Buffers Compiler version 2.5. Make sure that protoc is on your PATH.
  • Supported OSs where code was successfully built:
    • Windows : Windows 8, 10, Server 2012,2016
    • Linux: Ubuntu versions 16.04 and 16.10
    • macOS

Build Instructions

The REEF unit tests require a number of open files which is greater than the default open file limit on a number of Linux distributions such as Ubuntu 16.04/16.10. This limit is controlled in the shell by the “ulimit -n” command

The Java side of REEF is built using Apache Maven. All commands given below for building the code, running the tests or performing individual code quality checks can be used in two ways: when executed from the root directory of REEF project, they will build/run tests/checks on all Java projects in order of their dependencies, and when executed from an individual project's directory (for example, /lang/java/reef-common), they will build/run tests/checks on that project only.

To build and run tests, execute:

mvn clean install

REEF integration tests can take a while (~30 minutes on a modern multi-core machine), it may be faster to run one of the commands below which skips these tests.

To perform build alone without tests in a multithreaded mode, execute:

mvn -TC1 -DskipTests clean install

To perform “fast” build, which skips tests and all code quality enforcement tools, execute:

mvn clean install -DskipTests -TC1 -P!code-quality

Test Instructions

To run tests separately on local runtime, execute:

mvn test

Note that the tests will take several minutes to complete. You will also see stack traces fly by. Not to worry: those are part of the tests that test REEF's error reporting.

Code Quality Enforcement Tools

Java build incorporates several code quality tools:

  • Apache RAT verifies that Apache headers are in place where needed. To run this check separately, execute:

    mvn apache-rat:check

  • Checkstyle verifies that all Java code adheres to a coding standard. To run this check separately, execute:

    mvn checkstyle:checkstyle

    Per-project Checkstyle reports can be found at \<project>\target\site\checkstyle.html. Violations which caused the build break will show up as errors and need to be fixed; violations which show up as warnings or info can be ignored.

  • Findbugs looks for potential bugs in Java code, and can fail the build if any high-priority warnings are found. To run this check separately, execute:

    mvn findbugs:check xml:transform

    Per-project Findbugs reports can be found at \<project>\target\findbugs\findbugsXml.html.

Continuous Integration

We use Travis CI to run continuous integration for REEF Java code (i.e. build and run tests for all pull requests and commits to master branch). Our current setup runs 2 builds for each commit: Oracle JDK 8 and OpenJDK 7; REEF can run on Oracle JDK 7 but it has been dropped from Travis build images.

It can be convenient to set up Travis for your fork of REEF repository, for example, to reproduce a test failure which can't be reproduced locally.

  1. Log in to Travis CI using your GitHub credentials.
  2. Go to your profile and switch reef repository to “on”.
  3. Fine-tune configuration as required at Settings tab of repository; you can enable building pushes to your repository when you‘re investigating something and disable them when you don’t need them.
  4. Edit Travis configuration file as required (by default you'll use the same configuration as REEF build).