What is the most mature library for building a Data Analytics Pipeline in Java/Scala for Hadoop?

As I'm a developer of Scoobi, don't expect an unbiased answer.

First of all, FlumeJava is an internal google project that provides a (awesomely productive) abstraction ontop of MapReduce (not hadoop though). They released a paper about it, which is what projects like Scoobi and Crunch are based on.

If your only criteria is the maturity -- I guess Cascading is your best bet.

However, if you're looking for the (imho superior) FlumeJava style abstraction, you'll want to pick between (S)crunch and Scoobi.

The biggest difference, superficial as it may be is that crunch is written in Java, with Scala bindings (Scrunch). And Scoobi is written in Scala with Java bindings (scoobij). They're both really solid choices, and you won't go wrong which ever you choose. I'm sure there's quite a similar story with Crunch, but Scoobi is being used in real projects and is under continual development. We're pretty very active in fixing bugs and implementing features.

Anyway, they're both great projects with great people behind them and were both released within days of each other. They provide the same abstraction (with similiar api), so switching between the two won't be an issue in the slightest. My recommendation is to give them both a try, and see what works for you. There' no lock in in either project, so you don't need to commit :)

And if you have any feedback for either project, please be sure to provide it :)

I'm a big Scoobi fan myself and I've used it in production. I like the way it allows you to write type-safe Hadoop programs in a very idiomatic Scala way. If that is not necessarily your thing and you like the Cascading model but are scared off by the huge amount of boilerplate code you'd have to write, Twitter has recently open sourced its own Scala abstraction layer on top of Cascading called Scalding.

• Announcement: https://dev.twitter.com/blog/scalding
• GitHub: https://github.com/twitter/scalding

I guess it's all a matter of taste at this point since feature-wise most of the frameworks are very close to one another.

Scalding also has the advantage of significant open source projects built atop it, such as Matrix API and Algebird.

Here are some examples:http://sujitpal.blogspot.com/2012/08/scalding-for-impatient.html

Cascalog was released almost two years before Scalding, and arguably has more advanced features for building robust workflows:https://github.com/nathanmarz/cascalog/wiki