Distributed computing framework for Clojure/Java

Hadoop is the base for almost all the large scale big data excitement in the Clojure world these days though there are better ways than using Hadoop directly.

Cascalog is a very popular front end:

    Cascalog is a tool for processing data on Hadoop with Clojure in a concise and
    expressive manner. Cascalog combines two cutting edge technologies in Clojure 
    and Hadoop and resurrects an old one in Datalog. Cascalog is high performance, 
    flexible, and robust.

Also check out Amit Rathor's swarmiji distributed worker framework build on top of RabbitMQ. it's less focused on data processing and more on distributing a fixed number of tasks to a pool of available computing power. (P.S. It's in his book, Clojure in Action)

Although I haven't gotten to use it yet, I think that Storm is something that you might find useful to explore:

Storm is a distributed realtime computation system. Similar to how Hadoop provides a set of general primitives for doing batch processing, Storm provides a set of general primitives for doing realtime computation. Storm is simple, can be used with any programming language, and is a lot of fun to use!