Docker on Erwähnenswert

h2o webserver with docker

Tue, 01 Mar 2016 13:23:07 +0000

h2o was one of the earliest webserver supporting http2. To make the usability just a bit more convinient I packaged it as Docker image. Available at lkwg82/h2o-http2-server and will be kept in sync with new versions.

What is h2o? Link to heading

H2O is a new generation HTTP server that provides quicker response to users with less CPU utilization when compared to older generation of web servers. Designed from ground-up, the server takes full advantage of HTTP/2 features including prioritized content serving and server push, promising outstanding experience to the visitors of your web site.

Isolated web tests in docker

Sun, 25 Oct 2015 21:23:07 +0000

This is a simple tutorial to show you how easy it can be to run isolated webtests in docker.

Presumed you want to run your webtests in an isolated environment for the following reasons:

isolation from other test runs (same ports/same directories/…)
automatic cleanup of …
- orphaned processes (to avoid memory leaks of test agent)
- cleanup of build files (not filling disk up with temporary files)
repeatability (of course)

Note: Btw. with build files I include the temporary container and images as well. (I just had a bunch of stability tests, which means running tests more than 50 times. I had local memory fuckups twice.)

Detect when docker instance reached memory limit

Sat, 24 Oct 2015 21:23:07 +0000

I’d like to know if my test instance reached the memory limit and behaves a kind of different after that.

simple but slightly incorrect approach Link to heading

Just grab the kernel logs for oom-killer for the particular container id.

$ CONTAINER_ID=84ec6201e6a54
$ dmesg -T | grep -B2 docker-$CONTAINER_ID | grep -B1 oom-killer

outputs

--
[Sun Oct 25 22:06:17 2015] java invoked oom-killer: gfp_mask=0xd0, order=0, oom_score_adj=0

Limitation: This implies that kernel logs before and after are about the same issue.