I just wanted to share this experience from World Singles... Back in November 2009, we started developing with Scala. We needed a long-running process that published large volumes of changes from our member database as XML packets published to a custom search engine. The mapping from half a dozen tables in the database to a flat XML schema was pretty complex and the company had tried a number of solutions with mixed success in the past. I introduced Scala based on the promises of performance, concurrency and type safety - and conciseness (especially with XML being a native data type in Scala).
We've been running the Scala publishing daemons in production for most of two years. Generally they work pretty well but, under stress, they tend to hit Out of Memory exceptions and, after a lot of poking around, we became fairly convinced it was due (at least in part) to the default actor implementation in Scala. Scala is going to fold in Akka soon and we had been considering migrating to Akka anyone... But having introduced Clojure this year (after experimenting with it since about May last year), we figured we'd have a short spike to create a Clojure version of the Scala code to see how it worked out. It took about 15 hours to recreate the publishing daemon in Clojure and get it to pass all our tests. Today we ran a "soak test" publishing nearly 300,000 profiles in one run. The Scala code would fail with OoM exceptions if we hit it with 50,000 profiles in one run (sometimes less). The Clojure code sailed thru and is still happily running - so we'll be replacing the Scala code during our next production build. The other aspect that's interesting is that the Scala code totaled about 1,000 lines (about 31k characters of code). The Clojure replacement is just under 260 lines (around 11.5k characters of code). Neither code base has much in the way of comments (*ahem* - I'm not proud of that, just pointing out that there's no "noise" offsetting the code comparison). That doesn't include unit tests either, it's just the raw production code. The form of the Clojure code mostly follows the form of the Scala code, most of the same functions - it was very functional Scala - with some refactoring to helper functions to make it more modular and more maintainable. The net result is (obviously) that we'll be taking the Clojure publishing daemon to production and we'll be dropping Scala completely. Kudos to Rich Hickey and the Clojure/core team for creating a great general purpose language that can solve big problems - thank you! -- Sean A Corfield -- (904) 302-SEAN An Architect's View -- http://corfield.org/ World Singles, LLC. -- http://worldsingles.com/ Railo Technologies, Inc. -- http://www.getrailo.com/ "Perfection is the enemy of the good." -- Gustave Flaubert, French realist novelist (1821-1880) -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
