Contributor Tools

IDE

We recommend using either Eclipse or IntelliJ IDEA to contribute to Alluxio. Instructions for setting up both IDEs can be found below.

Eclipse

You can generate an Eclipse configuration file by running:

$ mvn clean -Pdeveloper install -DskipTests
$ mvn clean -Pdeveloper -DskipTests eclipse:eclipse -DdownloadJavadocs=true -DdownloadSources=true

Then import the folder into Eclipse. You may also have to add the classpath variable M2_REPO by running:

$ mvn -Declipse.workspace="your Eclipse Workspace" eclipse:configure-workspace

Note: Alluxio 2.2 moved generated gRPC proto source files into alluxio/core/transport/target/generated-sources/protobuf/. You will need to mark the directory as a source folder for Eclipse to resolve the source files.

IntelliJ IDEA

To use IntelliJ IDEA to contribute to Alluxio simply open IntelliJ and select “Import existing project”. Then select the “Maven” project type from the IntelliJ dialog. IntelliJ’s default configuration works without any modifications.

After successfully importing your local Alluxio repo into IntelliJ, you may need to add the Maven profile ‘developer’ in order to avoid import errors.

You can do this by going to

View > Tool Windows > Maven Projects

And then check the box next to “developer” in the window pane.

Note: Alluxio 2.2 moved generated gRPC proto source files into alluxio/core/transport/target/generated-sources/protobuf/. You will need to mark the directory as “Generated Sources Root” for IntelliJ to resolve the source files.

Maven Targets and Plugins

Before pushing changes or submitting pull requests we recommend running various maven targets on your local machine to make sure your changes do not break existing behavior.

For these maven commands we’ll assume that your command terminal is located in the root directory of your local copy of the Alluxio repository.

$ cd ${ALLUXIO_HOME}

Checkstyle

To make sure your code follows our style conventions you may run. Note that this is run any time you run targets such as compile, install, or test.

$ mvn checkstyle:checkstyle

FindBugs

Before submitting the pull-request, run the latest code against the findbugs Maven plugin to verify no new warnings are introduced.

$ mvn compile findbugs:findbugs

Compilation

To simply compile the code you can run the following command:

$ mvn clean compile -DskipTests

This will not execute any unit tests but will execute maven plugins such as checkstyle and findbugs.

To speed up compilation you may use the following command:

$ mvn -T 2C compile -DskipTests -Dmaven.javadoc.skip -Dfindbugs.skip -Dcheckstyle.skip \
  -Dlicense.skip -pl '!webui'

This command will skip many of our checks that are in place to help keep our code neat. We recommend running all checks before committing.

• -T 2C runs maven with up to 2 threads per CPU core
• -DskipTests skips running unit and integration tests
• -Dmaven.javadoc.skip skips javadoc generation
• -Dfindbugs.skip skips findbugs execution
• -Dcheckstyle.skip skips code-style checking
• -Dlicense.skip skips checking files for license headers
• -pl '!webui' skips building the Alluxio UI module. If this module isn’t compiled then the UI cannot be accessed locally.

You may replace the compile target in the above command with any other valid maven target to skip checks as well. The targets compile, verify, and install are typically the most useful.

Creating a Local Install

If you want to test your changes with a compiled version of the repository, you may generate the jars with the Maven install target. The first time Maven executes it will likely need to download many dependencies. Please be patient as the first build may take a while.

$ mvn -T 2C install -DskipTests

After the install target executes, you may configure and start a local cluster with the following commands:

If you haven’t configured or set up a local cluster yet, run the following commands to configure a local installation.

$ cp conf/alluxio-site.properties.template conf/alluxio-site.properties
$ echo "alluxio.master.hostname=localhost" >> conf/alluxio-site.properties
$ ./bin/alluxio format

Once you’ve run those commands steps you can start a local Alluxio instance with

$ ./bin/alluxio-start.sh local SudoMount

Unit Tests

• Run all unit and integration tests

$ cd ${ALLUXIO_HOME}
$ mvn test

This will use the local filesystem as the under storage.

• Run a single unit test:

$ mvn -Dtest=<AlluxioTestClass>#<testMethod> -DfailIfNoTests=false test

• To run unit tests for a specific module, execute the maven test command targeting the desired submodule directory. For example, to run tests for HDFS UFS module you would run

$ mvn test -pl underfs/hdfs

Run unit tests for HDFS UFS module with a different Hadoop version:

# build and run test on HDFS under storage module for Hadoop 2.7.0
$ mvn test -pl underfs/hdfs -Phadoop-2 -Dhadoop.version=2.7.0
# build and run test on HDFS under storage module for Hadoop 3.0.0
$ mvn test -pl underfs/hdfs -Phadoop-3 -Dhadoop.version=3.0.0

The above unit tests will create a simulated HDFS service with a specific version. To run more comprehensive tests on HDFS under storage using a real and running HDFS deployment:

$ mvn test -pl underfs/hdfs -PufsContractTest -DtestHdfsBaseDir=hdfs://ip:port/alluxio_test

• To have the logs output to STDOUT, append the following arguments to the mvn command

-Dtest.output.redirect=false -Dalluxio.root.logger=DEBUG,CONSOLE

• To quickly test APIs in an interactive manner, you may leverage the Scala shell, as discussed in this blog.

• The fuse tests are ignored if the libfuse library is missing. To run those tests, please install the libraries referenced in the Alluxio FUSE documentation.

Modifying a gRPC definition

Alluxio uses gRPC 1.17.1 for RPC communication between clients and servers. The .proto files defined in core/transport/src/grpc/ are used to auto-generate Java code for calling the RPCs on clients and implementing the RPCs on servers. To regenerate Java code after changing a gRPC definition, you must rebuild alluxio-core-transport module with 'generate' maven profile.

$ mvn clean install -Pgenerate

Modifying a Protocol Buffer Message

Alluxio uses Protocol Buffers 2.5.0 to read and write journal entries. The .proto files defined in core/transport/src/proto/ are used to auto-generate Java definitions for the protocol buffer messages.

To change one of these messages, first read about updating a message type to make sure your change will not break backwards compatibility. To regenerate Java code after changing a definition, you must rebuild alluxio-core-transport module with the 'generate' maven profile.

$ mvn clean install -Pgenerate

Usage of ./bin/alluxio

Most commands in bin/alluxio are for developers. The following table explains the description and the syntax of each command.

In addition, these commands have different prerequisites. The prerequisite for the format, formatWorker, journalCrashTest, readJournal, runClass, version, validateConf and validateEnv commands is that you have already built Alluxio (see Build Alluxio Master Branch about how to build Alluxio manually). Further, the prerequisite for the fs, logLevel, runTest and runTests commands is that the Alluxio service is up and running.