Cluster

The Raspberry PI needs several pieces of hardware and software to set it up.

Hardware

The cluster for this demo uses:

12 x Raspberry PIs V3. Each datacenter is made of 4 Raspberry PIs, as well as 4 Raspberry PIs for the clients
12 x Raspberry PI protective case in different colours, it’s better
12 x SD cards (8 Mb is enough)
3 x 5-Port Desktop Switch TL-SG105 to create a network between the 2 data centers and the clients.
12 x 6 inch ethernet cables to plug each Raspberry PI to the switch (different colours is better)
1 x Edge Router to route clients between the 2 data centers
3 x one foot ethernet cables to plug each switch to the router
3 x Zookki 6 Port USB Charger to electrically power the Raspberry PIs
12 x Retractable USB to Micro cable from the charger to the Raspberry PI
2 x Power strip with 6 sockets
Reusable fastening cable tie because you want to tie everything so it doesn’t look like a mess
1 x USB to SD Card Reader to flash the SD cards

To setup the Raspberry PI Cluster you need the following tools to be installed:

Docker
Ansible (how to install it)
The Hypriot flash utility
(optional) Pipe Viewer to monitor the progress of data (handy when flashing SD cards)
(optional) SSHPASS

For this demo, the cluster is setup as follow:

Clients
- 3 Raspberry PIs acting as clients browsing the 2 data centers (pi-client-01, pi-client-02 and pi-client-03)
- 1 Load balancer for the clients (pi-client-load-balancer)
Data center Thrall
- 1 load balancer (pi-thrall-load-balancer)
- 2 servers (pi-thrall-server-01 and pi-thrall-server-02)
- 1 database (pi-thrall-database)
Data center Grom
- 1 load balancer (pi-grom-load-balancer)
- 2 servers (pi-grom-server-01 and pi-grom-server-02)
- 1 database (pi-grom-database)

Important

It is important to electrically start the router and switches first, and a few seconds later, the Raspberry PI.