f18m/cmonitor repository overview

⁠Usage scenarios and HTML result examples

⁠Monitoring the baremetal server (no containers)

In this case you can simply install cmonitor as RPM or APT package following instructions in How to install⁠ and then launch the cmonitor collector as any other Linux daemon. Example results:

1. baremetal1⁠: example of graph generated with the performance stats collected from a physical (baremetal) server running Ubuntu 18.04; note that despite the absence of any kind of container, the cmonitor_collector utility (like just any other software in modern Linux distributions) was running inside the default "user.slice" cgroup and collected both the stats of that cgroup and all baremetal stats (which in this case mostly coincide since the "user.slice" cgroup contains almost all running processes of the server);

2. baremetal2⁠: This is a longer example of collected statistics (results in a larger file, may take some time to download) generated with 9 hours of performance stats collected from a physical server running Centos7 and with 56 CPUs (!!); the cmonitor_collector utility was running inside the default "user.slice" cgroup so both "CGroup" and "Baremetal" graphs are present;

⁠Monitoring the baremetal server from a Docker container

In this case you can install cmonitor Docker using the official DockerHub image, see Docker⁠; the Docker container will collect all performance stats of the baremetal. Just run it

docker run -d \
    --name=cmonitor-baremetal-collector
    -v /root:/perf \
    f18m/cmonitor

Example results:

1. docker_centos7_collecting_baremetal_stats⁠: example of graph generated with the performance stats collected from a physical server from inside a Docker container; in this case cgroup stat collection was explicitely disabled so that only baremetal performance graphs are present;

⁠Monitoring your Docker container embedding cmonitor inside it

If you can easily modify the Dockerfile of your container, you can embed cmonitor so that it runs inside your container and monitor your dockerized-application. Example of the Dockerfile modified for this purpose:

...
COPY cmonitor_collector /usr/bin/   # first you need to grabthe cmonitor binary for your Docker base image
CMD /usr/bin/cmonitor_collector \
      --sampling-interval=3 \
      --output-filename=mycontainer.json \
      --output-directory /perf ; \
    myapplication
...

Example results:

1. docker_ubuntu1804_userapp_with_embedded_collector⁠: example of graph generated with the performance stats collected from inside a Docker container using Ubuntu as base image; this is a practical example where the Docker container is actually deploying something that simulates your target application, together with an embedded cmonitor_collector instance that monitors the performance of the Docker container itself; in this case both cgroup stats and baremetal performance graphs are present.
2. docker_centos7_userapp_with_embedded_collector⁠: same graph as example n. 2, but obtained from a Docker container running Centos 7 instead of Ubuntu as base image.

⁠Monitoring your Docker container from the baremetal

In this case you can simply install cmonitor as RPM or APT package following instructions in How to install⁠ and then launch the cmonitor collector as any other Linux daemon, specifying the name of the container it should monitor, e.g.

docker run --name userapp myuserapp-docker-image

# here we exploit the following fact: the cgroup of each Docker container 
# is always named 'docker/container-ID'
cmonitor_collector \
  --sampling-interval=3 \
  --output-filename docker-userapp.json \
  --cgroup-name=docker/$(docker ps --no-trunc -aqf name=userapp)

Example results:

1. docker_userapp⁠: example of the chart generated by monitoring from the baremetal a simple docker simulating your application, doing some CPU and I/O

cmonitor_collector --remote-ip=1.2.3.4 --remote-port=8086

make -C examples regen_grafana_screenshots