Spring Hadoop is a framework extension for writing Hadoop jobs that benefit from the features of Spring, Spring Batch and Spring Integration. The feature set is limited right now to support for dependency injection in simple Hadoop jobs. If you have ideas about how to improve or extend the scope, please feel free to contribute (see below for instructions).
Clone the source code and run
mvn install (we use 2.1.x) from the
command line, or import as a Maven project into SpringSource Tool
Suite (STS). There are some integration tests that show you what you
can do. For example (from
JobTemplate jobTemplate = new JobTemplate(); jobTemplate.setVerbose(true); assertTrue(jobTemplate.run("/spring/autowired-job-context.xml"));
This runs a simple word count job (per the online tutorial on the Hadoop home page). Such a simple job doesn't benefit much from dependency injection, but it shows the basic principles, and will feel very comfortable to existing Spring users. More complex jobs, especially with externalise parameterisation of the components, will benefit greatly from having a container to manage the dependencies.
The test code above runs the job locally by default. To run it in a
Hadoop cluster you need to run the cluster (of course) and provide
configuration for a jar file containing the job and for the job
tracker and distributed file system. You can generate a jar file by
mvn assembly:single and then using the settings already in
the test. The test case also sets up the job tracker host for the job
configuration (the default settings will work for a local job tracker
with the settings from the Hadoop getting started
HadoopSetUp test utility is used in the test to sets up the
cluster properties if it detects the local job tracker.
Contributing to Spring Hadoop
Github is for social coding: if you want to write code, we encourage contributions through pull requests from forks of this repository. Before we accept a non-trivial patch or pull request we will need you to sign the contributor's agreement. Signing the contributor's agreement does not grant anyone commit rights to the main repository, but it does mean that we can accept your contributions, and you will get an author credit if we do. Active contributors might be asked to join the core team, and given the ability to merge pull requests.