Profilertest package runs end to end tests for the APIs written in the profiler package. It does this by simulating perfomance regression for different components, generating their USE reports and checking that the stress on each component was reflected in the USE metrics collected.
End to end tests can be run in a Docker container, which can be built using the Dockerfile in the profilertest package. This ensures that end to end tests are isolated from other processes running on the host machine. To build a docker image for the profilertest package, it is important to be in the tools directory in which go.mod and go.sum files are present because the Docker image needs to copy dependencies from the aforementioned files and get context from them. Then, run the following commands:
docker build -t <image-name> -f src/pkg/nodeprofiler/profilertest/Dockerfile .
The above command will create a Docker image that can be used to create a Docker container. To run the container, it is best to set runtime options with memory and cpu limits. This can be done as follows:
docker run -it --cpus="<percentage of cpu to use>" -m=<number of megabytes to give to the container>m <image-name>
Example: The following will allocate 50% of the CPU every second and 200 megabytes of memory to the container with profiler-test image on it:
docker run -it --cpus=".5" -m=200m profiler-test
The above command will create an interactive shell from which we can navigate to the profilertest package as follows:
cd /work/src/pkg/nodeprofiler/profilertest/
To run the tests, use the following command:
go test . -v
More information about specifying runtime options with memory and cpu information can be found at: https://docs.docker.com/config/containers/resource_constraints/
To accomplish this, the tests makes use of the Linux package “stress-ng” which can stress test a Linux computer system in various selectable ways. The tool can be run as a shell command and can be configured by passing in a number of options. This configuration can be general options to modify the behavior of stress-ng or it can be specific to the type of stressor being used. Here's a general format of how to use the command:
stress-ng <general stress-ng options> <type of stressor> <number of workers> <stressor-specific options>
Examples:
stress-ng --cpu 2 --cpu-load 95 -t 10s
load CPU, and specifically 2 processors, with 95 percent loading for the 2 CPU stress workers (each for 1 processor) for 10 seconds
stress-ng --vm-bytes 256M -m 1 --vm-keep
start 1 stress worker that will continually write to the allocated memory thus overloading memory capacity
stress-ng --help
shows more information about package usage
Further documentation on the stress-ng package can be found by typing “man stress-ng” or on ubuntu's man pages: https://manpages.ubuntu.com/manpages/artful/man1/stress-ng.1.html
The version of “stress-ng” used to run tests in package profilertest is 0.09.50. To download the “stress-ng” package, the following command can be used:
$ sudo apt install stress-ng (on Ubuntu/Debian) $ yum install stress-ng (on Fedora/CentOS)