Gaug.es uses Mongo. Its data model is pretty simple (just counters), but he has blogged about the approach in detail. MongoDB Counters: http://railstips.org/b

Gaug.es uses Mongo. Its data model is pretty simple (just counters), but he has blogged about the approach in detail. MongoDB Counters: http://railstips.org/blog/archives/2011/06/28/counters-everywhere/ http://railstips.org/blog/archives/2011/06/28/counters-every... http://railstips.org/blog/archives/2011/07/31/counters-everywhere-part-2/ http://railstips.org/blog/archives/2011/07/31/counters-every... Kestrel: http://railstips.org/blog/archives/2012/03/05/misleading-title-about-queueing/ http://railstips.org/blog/archives/2012/03/05/misleading-tit... Gets some decent traffic and works well. http://twitter.com/jnunemaker/status/282141258816827393 http://twitter.com/jnunemaker/status/282141258816827393