Introducing Wee Archie

Author: Alistair Grant
Posted: 26 Nov 2015 | 15:29

 

The EPCC Outreach team is always looking for new ways to introduce supercomputing to a general audience. Remote connections to ARCHER could be used, but how would audiences know what is happening? Is it really running on a remote system or is it faked? Enter Wee Archie: a portable, functional cluster developed by EPCC to demonstrate applications and concepts relating to parallel systems. 

Wee Archie has been designed to meet the following criteria:

  • Transportability - the design is robust and portable, and only requires a network and power cable to be attached.
  • Functionality - Wee Archie will demonstrate parallel concepts, and this is best done through running applications.
  • Visibility – the connections between components of complex systems are often hidden from the general user. Wee Archie is designed to expose the connections and hardware safely.

A computation node – board and matrix indicator.

Wee Archie consists of 18 Raspberry Pi 2 Model B boards with three network switches housed in a custom design casing. Sixteen of these boards are for computation; the other two form a control and monitoring system. Each board has an associated LED matrix used to show live operational metrics.

The custom cluster housing.

Using Wee Archie: an application

Dinosaur racing has been a popular activity at EPCC outreach events for several years: audiences can configure their own simulated dinosaur, with the resulting movement data used to create races against other dinosaurs. This has worked well when the application is able to run the simulation engine on ARCHER, the UK national HPC service. But the amount of data that needs to be communicated is large and not every outreach venue has a sufficiently fast internet connection. A laptop can run the simulation, but is very slow and lessens the impact of the application. 

Wee Archie with its 64 computation cores addresses this problem. The dinosaur simulation code has been ported to Wee Archie, allowing us to run the code in a parallel system without concern about remote connections. 

The audience can watch the machine in use, seeing how multiple parts of the system work together: as the LED matrices change from idle to busy, each shows the amount of work being done to simulate their dinosaur.  

The instructions for building a smaller version of the cluster in Wee Archie are undergoing testing and will be available towards the end of February 2017.

Authors

Nick Brown and Alistair Grant, both EPCC.

Comments

Will you be making the software stack available for other cluster builders?

And how does the LED Matrix display work?

A guide on how to put together a Raspberry Pi cluster like Wee Archie will be put online in the coming months, accompanied by the first of our demo codes for the clusters. When these are ready, there will be an announcement with links to them.

The LED Matrix is driven by a Python script which queries system information and uses it to display different metrics about the Pi it is attached to such as processor load, temperature, network traffic in and out. The LED Matrix is connected via the GPIO pins on the Pi.

Hi Alistair

Are the instructions for putting together a Wee Archie like cluster available somewhere yet?

The instructions for putting together a small cluster of Raspberry Pi computers with the focus on the software setup will be done soon - aiming for February - they are undergoing testing at the moment - a blog article will be posted when they are ready for people to use. If you are looking for fuller instructions on how to construct the case and how the cabling is laid out, then if you have specific questions please get in contact.