From ba144fab071258a97cf3c42a0defeb0aae41a353 Mon Sep 17 00:00:00 2001 From: "Suren A. Chilingaryan" Date: Sun, 6 Oct 2019 05:00:55 +0200 Subject: Document latest problems with docker images and resource reclaimation, add docker performance checks in the monitoring scripts, helpers to filter the logs --- docs/users.txt | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100644 docs/users.txt (limited to 'docs/users.txt') diff --git a/docs/users.txt b/docs/users.txt new file mode 100644 index 0000000..c28f400 --- /dev/null +++ b/docs/users.txt @@ -0,0 +1,21 @@ +Dockerfiles +=========== + - Long (many-layer) Dockerfiles may cause a significant disruption to the OpenShift cluster (far behind just performance penalty + of working with this layers). Currently, it is imperative to reduce the number of intermediate images resident on the OpenShift nodes. + * The better approach is to optimize Dockerfiles: All ENV defined at once, as few ARG as possible, signle COPY, and a single RUN to + setup everything. + * Alternatively, the final image can be squashed with 'docker build --squash ...' (enable experimental features in docker daemon). + However, this is incompatible with OpenShift build process. + If optimizing already running applications, it is not enough just to re-build images. Old images could be referenced by the old + 'rc' left in the system or even stopped containers lost by OpenShift infrastructure. + * Check if old images still present (https://github.com/TomasTomecek/sen is only application I am aware of capable of showing it) + * See maintenance section how to get rid if old images are still present + +Deployments +=========== + - CronJobs is currently a bit problematic and periodically cause some lost resources, etc. They can be used if necessarily, but it better + to minimize. In any case, it is crucial to minimize size of frequently scheduled Job containers (otherwise large I/O). + + +Storage +======= -- cgit v1.2.1