TL;DR: Java and cgroups/Docker memory constraints don’t always behave as you might expect. Always explicitly specify JVM heap sizes. Also be aware that kernel features may not be enabled. And Linux… lies. I’ve recently discovered an interesting “quirk” in potential interactions between Java, cgroups, Docker, and the kernel which can cause some surprising results. Unless …
Category Archive: Experiments
Oct 02
Multifarious v2
While at a DevOps Birds of a Feather session at Ohio Linux Fest today I was describing to John Willis (@botchagalupe) my experiments with Docker and the Pi Swarm. Along the way, I mentioned that I’d gotten heterogenous docker swarms working using Powerstrip — aka Multifarious, first described in Heterogenous Docker Swarms Teaser. In so …
Apr 28
Heterogenous Docker Swarms Teaser
Note: This is all very experimental; Docker does not support any architecture other than X86_64. The last few evenings I’ve been working on Mulitifarious, a means of creating heterogenous Docker Swarms. I’d previously found that I can create a swarm with heterogenous members — a swarm which has, say, X86_64 and Raspberry Pi members. The …