Script to measure the total CPU utilization and RAM usage of Docker container.
Execute on a docker host environment, where container is located which you are planning to measure:
$ container_stats.sh <container_name> [<interval for collection (seconds)>]
Default interval is 0.1 second.
On run script will:
- Wait for container to start if it is not running or stopped.
- Copy one AWK script into container. It is used to pre-process the collected metrics.
- Collect stats for CPU utilization in the system.
- Collect stats for memory usage for all processes inside the container except bash, awk, date, head. Could be an issue if your process is bash, update the script accordingly.
- On container stop or Ctrl-C, postprocess the collected metrics and output them in CSV format to stdout.
- Remove the AWK script from container (copied on step 2).
Example of the produced CSV:
timestamp_ms,cpu_percent,mem_usage_bytes
1614167079867,50,700416
1614167079971,50,700416
1614167080076,54.5455,700416
- Increased frequency of collection (smaller values for the interval) will show more spikes in CPU consumption.
- It will also mean that the measurement script itself consumes more CPU.
- cgroups info which is used by
docker statscommand does not always produce the reliable results according to our experiments.