Cloud Haskell

Cloud Haskell is a domain-specific language for developing programs for a distributed computing environment. Implemented as a shallow embedding in Haskell, it provides a message passing communication model, inspired by Erlang, without introducing incompatibility with Haskell’s established shared-memory concurrency.

Availability

Cloud Haskell is available from Hackage as distributed-process. You might also want to install distributed-process-simplelocalnet. The cutting edge development version is on github.

There is also the older prototype implementation remote (also available from github).

Documentation

For an overview of Cloud Haskell it's probably a good idea to read Towards Haskell in the Cloud (details below). The relevant documentation (in order of importance is)

• Control.Distributed.Process
• Control.Distributed.Process.Closure
• Control.Distributed.Process.Node

and

• Control.Distributed.Process.SimpleLocalnet

If you want to know more details about Closure or Static (without the Template Haskell magic on top) you might want to read

• Control.Distributed.Static

Videos and Blog Posts

Cloud Haskell intros

• blog: A Cloud Haskell Appetiser (Parallel Haskell Digest 11)
• video: (1hr) Cloud Haskell: a general introduction and tutorial, focusing on what it does and how to use it. It also covers some details about the current implementation.
• video: (1hr) Towards Haskell in the Cloud: an older but more detailed introduction by Simon Peyton Jones about the problem area and the design decisions and internals of Cloud Haskell. In particular it covers the details of how sending functions over the wire really works.

Well-Typed have a series of blog posts "Communication Patterns in Cloud Haskell"

• Part 1: Master-Slave, Work-Stealing and Work-Pushing
• Part 2: Performance
• Part 3: Map-Reduce
• Part 4: K-Means

Alen Ribic has a series of blog posts about (Cloud) Haskell on the Raspberry Pi

• Running Haskell on Raspberry Pi
• Raspberry Pi in a Haskell Cloud

Papers

• Towards Haskell in the Cloud, Jeff Epstein, Andrew Black, and and Simon Peyton Jones. Haskell Symposium, Tokyo, Sept 2011.
• Functional programming for the data centre, Jeff Epstein. Masters Thesis, University of Cambridge, 2011

Other Useful Packages

Serializable

A core concept in Cloud Haskell is that of serializable values. The Serializable type class combines Typeable and Binary. ghc can automatically derive Typeable instances for custom data types, but you need a package to derive Binary. There are various packages available that assist with this:

• binary-generic
• binary-derive
• generic-binary
• derive

binary-generic and derive have been confirmed to work with Cloud Haskell; the status of the other packages is unknown -- YMMV (please feel free to update this wiki page if you have more information).