Hawkular APM and instrumenting clojure
by Neil Okamoto
As an experiment I'm instrumenting a service written in clojure using
opentracing-java. Through the clojure/java interop I've mostly succeeded
in getting trace information reported through to the Hawkular APM server.
I say "mostly succeeded" because sooner or later in every one of my hacking
sessions I get to the point where the spans I am creating in the app are no
longer reported in the web ui.
For convenience I'm using the Hawkular dev docker image
<https://hub.docker.com/r/jboss/hawkular-apm-server-dev>. In my test app
I'm doing nothing more than initializing an APMTracer
<https://github.com/hawkular/hawkular-apm/blob/master/client/opentracing/s...>
with
the appropriate environment variables set, and then calling
buildSpan("foo"), withTag("sampling.priority", 1), start(), sleep for a
while, and then finish(). Where all of the previous was done in clojure,
but I'm talking in pseudocode here just to make the intent clear.
So like I said, sometimes these traces are reported, other times they seem
to be silently dropped. I can't detect any consistent pattern how or why
this happens...
(1) Is using a "sampling.priority" of 1 merely advisory? It would explain
everything if those traces are meant to be dropped.
(2) Is there any convenient way I can see, with increased logging or
something, which traces are actually being sent from the client, and which
are actually received by the server?
8 years, 7 months
Docker image size does matter
by Jiri Kremser
Hello,
I was looking into google/cadvisor docker image that is only 47 megs
large and wondering how we can improve. To some extend it is so small
because of the Go lang, but not only.
Here are the results:
base image with JRE 8 and Alpine linux: 76.8 MB
wildfly 10.1.0.Final image 215 MB
hawkular-services 320 MB
Just for the record, here is status quo:
base CentOS image w/ JDK 8: 149 MB
wf image: 580 MB
hawkular-services image 672 MB
All the mini-images are based on Alpine (that itself is based on BusyBox),
so the price for it is less convenience when debugging the images.
I also removed
9.2M /opt/jboss/wildfly/docs
and wanted to remove
9.0M /opt/jboss/wildfly/modules/system/layers/base/org/hibernate
5.1M /opt/jboss/wildfly/modules/system/layers/base/org/apache/lucene
5.6M /opt/jboss/wildfly/modules/system/layers/base/org/apache/cxf
but from some reason the h-services fails to start because it didn't found
some class from that hibernate module, so I rather put it back.
What also helped was squashing all the image layers into 1. This makes the
download faster and possibly the image smaller. When applying docker-squash
[1] to the current h-services image it saves ~50megs
I am aware that this probably wont fly with some RH policy that we should
base our SW on Fedora/RHEL base OS images, but I am gonna use them for
development and because I often run out of space because of Docker.
Oh and I haven't published it on dockerhub yet, but the repo is here [2]
jk
[1]: https://github.com/goldmann/docker-squash
[2]: https://github.com/Jiri-Kremser/hawkular-services-mini-dockerfiles
8 years, 7 months