The repository for the final project of the SPE course.

Install the conda environment

conda env --file environment.yml

1. Run the following command to apppend the appropriate stanza to /etc/apt/sources.list, replacing $release with your Linux release (ex. bionic).

    echo "deb https://nginx.org/packages/ubuntu/ $release nginx" | sudo tee /etc/apt/sources.list.d/nginx.list

2. Run the following commands in a shell:

    sudo apt-get update
    sudo apt-get install nginx

For any problem refer to https://www.nginx.com/resources/wiki/start/topics/tutorials/install/

3. You may want to disable auto-start of NGINX at startup of computer:

sudo systemctl disable nginx

The fastest way is to download the binary file from GitHub at the following link. Install the binary in your PATH to run k6 from any location. This can be, for example, /usr/local/bin.

Install an updated version of NodeJS using nvm

nvm install --lts=Erbium

To start a simulation, open three different shells.

Start NGINX with the following command:

nginx -c nginx/nginx.conf -p "$PWD"

Let Docker do the magic with:

docker-compose up

Launch the load test with k6:

k6 run script.js --out influxdb --duration 20s

Servers are implemented with Node Express and TypeScript. The first time you have to run npm install to install the project dependencies.

If you edit the server.ts file, then run npm run tsc to compile it. The result will be located in the build folder.

• PORT*: the port the requests are sent to
• SERVER_ID*: the server identifier
• SEED: a value that can be provided to produce consistent results. If not defined, the pseudorandom number generator uses the current date under-the-hood.
• MIN_RESPONSE_TIME: the time after which the server responds to a request.
• EXP_RESPONSE_TIME: If defined, the server draws a random values from an exponential distribution.
• LAMBDA: the lambda parameter of the exponential distribution. Default = 1.

• AUTOSCALE: if true, autoscale the number of servers
• AUTOSCALE_INCREASE_THRESHOLD
• AUTOSCALE_DECREASE_THRESHOLD
• AUTOSCALE_POLICY: "RESPONSE_TIME" | "REQUESTS_PER_SECOND"

• LOAD_BALANCING: Nginx load balancing policy default: round-robin

• K6_ITERATIONS: Number of iterations for each virtual user
• K6_VUS: Number of concurrent requests

Variables with * are automatically provided by the Bash script that bootstraps the servers.

To start a simulation run, run the following command. The environment variables need to be declared inline before the script.

MIN_RESPONSE_TIME=100 NUM_SERVERS=1 npm run simulation

NGINX_SERVER_PARAM=max_conns=5 LOAD_BALANCING=least_conn NUM_SERVERS=2 MIN_RESPONSE_TIME=100 EXP_RESPONSE_TIME=true K6_ITERATIONS=10000 K6_VUS=20 LAMBDA=0.01 SEED=10 K6_RPS=100 npm run simulation

Clear all series in influxdb

docker-compose exec influxdb influx -database k6 -execute 'DROP SERIES FROM /.*/'

docker-compose exec influxdb influxd backup -portable -db k6 /influx_backup

docker-compose exec influxdb -execute 'DROP DATABASE k6' docker-compose exec influxdb influxd restore -portable -db k6 /influx_backup

Use the following command

systemd-run --slice=user.slice --scope -p CPUQuota=100% nginx -c nginx/nginx.conf -p "$PWD"

MIN_RESPONSE_TIME=100 SERVER_ID=0 PORT=5000 systemd-run --scope --slice=user.slice -p CPUQuota=100% node build/server.js

SIMULATION=40 K6_ITERATIONS=^C0000 K6_VUS=100 systemd-run --scope --slice=user.slice -p CPUQuota=100% k6 run -o influxdb src/http_requests.js