Bejjans Networking Laboratory


In the mind of Bejjan

RPi Cluster


Following is my journey of building a container cluster.

I will fill this in over time as I'm harvesting all my old notes and pictures.

The RPi cluster has about 576 GFLOPs across all the nodes. 24GFLOP per CPU (BCM2837) according to specification.

Total compute resources sums up at 96 cores and 24GB of RAM. Blockstorage was limited to the SD-cards 16GB. However their persistent storage is now provided over network shared storage.

"Because science isn't always perfect :)"

Original post date: 2016-08-19

To give some context, this was way back before Docker Swarm existed. Containers had just begin to hype.

See, back then, Swarm was not built in to Docker, you had to set it up yourself. To do so, you had to set up etcd and consul, and run DIND to form your cluster.

Image featuring 4 nodes running HypriotOS(*)
* HypriotOS made by the Docker "Pirates" over at

"Do you compute ?"

Original post date: 2016-10-28

During building and planning I tried various ways of putting the cluster together.

View of 12 nodes in an array setup.

"Things are starting to look really nice!"

Original post date: 2016-10-30

"Things are starting to look really nice!"

Front view of halfway assembled cluster.

Back view of halfway assembled cluster.

"So yea, I did it... I built a little Docker Swarm cluster on RaspberryPi. This is what it looks like!"

Original post date: 2016-11-24

Going back and forth on the physical layout and assembling. I was trying to figure out optimal mouting angles. I wanted to fit the pi-stacks on the cover of the switch, along with the powersupplys.

Turns out the nail bands I had laying around was a perfect fit between the holes and the mouting studs on the pi's.

View of the 24 nodes running and lined up using a nail band.

"Assembly complete! 24x RBPi3!"

Original post date: 2016-12-05

After many late evenings getting it all ready it was finally complete! The result is quite amazing.

24x pi3
24x 16GB microsd-cards
1x24 port 100mbit switch
2x 26A psu's
And a whole lot of cables.

The cables were manufactured by hand, by cutting short USB-to-MicroUSB cables and soldering them to high capacity cables.

After strapping the network cables together and trimming the bandit straps.

Let there be light!

I decided on this angle so that I could access the MicroUSB ports easier.

Visualizer on a Raspberry Pi 3 with a handy 7" touch-screen. :-)

Original post date: 2017-01-13

And here is a little visualization of the cluster.