At the beginning of September, we announced the first release of CDH2, our current testing repository. Packages in our testing repository are recommended for people who want more features and are willing to upgrade as bugs are worked out. Our testing packages pass unit and functional tests but will not have the same soak time as our stable packages. A testing release represents a work in progress that will eventually be promoted to stable.
As Hadoop adoption increases among organizations, companies, and individuals, and as it makes its way into production, testing MapReduce (MR) jobs becomes more and more important. By regularly running tests on your MR jobs–either invoked by developers before they commit a change or by a continuous integration server such as hudson–an engineering organization can catch bugs early, strive for quality, and make developing and maintaining MR jobs easier and faster.
MR jobs are particularly difficult to test thoroughly because they run in a distributed environment.