Richard Bucker

Another case against Raspberry Pi Docker Clusters

Posted at — Mar 24, 2016

I really like the idea of the Raspberry Pi; RPI for short. From the perspective of the IoT, internet of things, it’s a great place to practice. Chances are that your next IoT project will be based on the ARM processor. ARM seems to be making inroads because of it’s cost, power, size (Pi Zero) and even with it’s limitations it’s still a capable machine.

However, while it’s novel to build Docker clusters in order to test various operational theories it’s not that real. Just on memory alone the container to host ratio is so much smaller than something like the Intel NUC with 32GB.

The case against RPI is what I just discovered. My two node cluster is running Weave Scope and csysdig in order to monitor the containers, host, resources and apps. With each sampling I see that scope and csysdig are consuming about 30-40% of the systems CPU. I though that scope’s websocket webapp might be the bottleneck but it’s not. The twp processes are also taking about 250M of physical memory and scope has allocated between 1-3G.

The percentage works it’s way into a real number… and that is going to count against the RPI severely.