Apache MRUnit

Apache MRUnit lets developers write unit tests that can be used in detecting problems with MapReduce jobs before their run on the database itself.

By unit testing Hadoop's MapReduce jobs, developer can avoid useless resource consumption, a good habit to have since Hadoop databases are usually used on large and very costly database clusters.

MRUnit works with Hadoop's 1.x and 2.x branches, along with Apache Avro.

Usage instructions are included with the MrUnit package.

What is new in this release:

• Update versions of Hadoop we compile against
• Throw assertion error if drivers are reused
• Key object re-use in Reducer is inconsistent with MapReduce behaviour (new API)

What is new in version 1.0.0:

• Multiple input key-value pairs now supported.
• DistributedCache testing support.
• Use of real OutputFormats now allowed.