Squall is an online query processing tool built on top of Storm (https://github.com/nathanmarz/storm). Similar to how Hive provides SQL syntax on top of Hadoop for doing batch processing, Squall executes SQL queries on top of Storm for doing online processing. In the long term, Squall is intended to move beyond SQL and to become an online analytics engine that supports statistics languages such as R.
This is work in progress, currently it is in development stage. Squall is being actively developed by several contributors from EPFL DATA lab, and from the students taking our database class. We provide a binary containing compiled Java classes, so it can be run out of the box. The source code is open-source and the system is free of charge.
Documentation and can be found on the Squall wiki.