Penny is a framework for creating custom Pig monitoring and debugging tools. It comes with a library of a dozen or so tools, for example:
- crash investigation – why did my pig script crash?
- record tracing – trace a particular record through the steps of a pig script, and show how it gets transformed
- integrity alerts – send an alert if a record passing between steps i and j fails to satisfy a particular predicate
- overhead profiling – which steps in the pig script dominate the running time?
But the real power of Penny is in creating your own, custom, monitoring and debugging tools using Penny's simple API. It's easy. Try it!