In this chapter, we completed an in-depth review of many techniques used to debug and test a Cascading application. You learned how to set up Cascading developer configurations for rapid and thorough testing. We looked at several facilities and techniques for debugging, including the use of specialized filters such as Debug(), how to write log messages, and how to review the overall structure of your Cascading application visually. We also reviewed various testing strategies for unit, integration, and load/performance testing.

In the next chapter, we will take a look at some specific techniques that you can use to optimize the performance of your Cascading applications, and also how the performance and tuning of the underlying platform (that is, Hadoop) can be optimized to further assess and improve performance.