load_test - Code-Over-Time/varcade_games GitHub Wiki
In order to generate some traffic on our distributed system we're going to use a tool called k6, which is an:
Open source load testing tool and SaaS for engineering teams
It's a tool written in GoLang that allows us to write Javascript in order great load tests.
To get set up with k6 you should follow the official documentation for your system.
!!! Important If you are using Windows you need to follow the Linux instructions using your Linux shell, since you will be running the load test from within your Linux environment.
In order to run the load test navigate to the build_tools/load_generator directory on your command line.
In that directory is a Javascript file that contains a script that will spawn 500 virtual users.
Those users will each register a new account and run the various requests a browser would run to load the website. It will also create new Rock Paper Scissors Apocalypse multi-player games and play the game.
To run the script enter the following command:
k6 run site_navigation.jsIf you get an error you should verify that your installation of k6 and its dependencies were all successful.
If everything works you should see some output like this flash by on the screen:
/\ |‾‾| /‾‾/ /‾‾/
/\ / \ | |/ / / /
/ \/ \ | ( / ‾‾\
/ \ | |\ \ | (‾) |
/ __________ \ |__| \__\ \_____/ .io
execution: local
script: site_navigation.js
output: -
scenarios: (100.00%) 1 scenario, 500 max VUs, 15m30s max duration (incl. graceful stop):
* default: 500 looping VUs for 15m0s (gracefulStop: 30s)
INFO[0000] Fetching VCG client, identifier: 1272 source=console
INFO[0000] Fetching VCG client, identifier: 1957 source=console
INFO[0000] Fetching VCG client, identifier: 8352 source=console
INFO[0000] Fetching VCG client, identifier: 4549 source=console
INFO[0000] Fetching VCG client, identifier: 4845 source=console
INFO[0000] Fetching VCG client, identifier: 2130 source=console
INFO[0000] Fetching VCG client, identifier: 4910 source=console
INFO[0000] Fetching VCG client, identifier: 7115 source=console
There are a couple of things worth noting here.
k6 tells us that it is running 500 VUs, which means 500 Virtual Users.
It also says 15m30s max duration, telling us that this test will run for 15 minutes. That means our users will load the website, create games and play games for 15 minutes straight.
This gives us an understanding of how the whole system will handle load over a specific period of time. If you want the end the text early you can just hit ctrl+c. Once the test has finished a summary will be displayed:
running (00m02.8s), 000/500 VUs, 0 complete and 500 interrupted iterations
default ✗ [--------------------------------------] 500 VUs 00m02.8s/15m0s
WARN[0003] No script iterations finished, consider making the test duration longer
█ landing and registration
✗ statusCode
↳ 99% — ✓ 512 / ✗ 1
█ homepage
✓ statusCode
checks.........................: 99.80% ✓ 512 ✗ 1
data_received..................: 393 kB 138 kB/s
data_sent......................: 160 kB 56 kB/s
group_duration.................: avg=1.98s min=1.21s med=2.03s max=2.72s p(90)=2.56s p(95)=2.64s
http_req_blocked...............: avg=8.57ms min=57.68µs med=2.72ms max=35.66ms p(90)=31.5ms p(95)=33.75ms
http_req_connecting............: avg=8.35ms min=39.69µs med=2.62ms max=35.63ms p(90)=31.45ms p(95)=33.57ms
http_req_duration..............: avg=175.8ms min=33.35ms med=165.71ms max=1.62s p(90)=217.07ms p(95)=224.57ms
{ expected_response:true }...: avg=174.06ms min=33.35ms med=165.57ms max=1.62s p(90)=217.05ms p(95)=224.44ms
http_req_failed................: 0.19% ✓ 1 ✗ 512
http_req_receiving.............: avg=33.86µs min=15.58µs med=29.85µs max=119.25µs p(90)=52.29µs p(95)=60.46µs
http_req_sending...............: avg=1.24ms min=17.03µs med=213.58µs max=48.79ms p(90)=2.12ms p(95)=9.78ms
http_req_tls_handshaking.......: avg=0s min=0s med=0s max=0s p(90)=0s p(95)=0s
http_req_waiting...............: avg=174.52ms min=26.01ms med=164.44ms max=1.62s p(90)=217.02ms p(95)=224.51ms
http_reqs......................: 513 180.657393/s
vus............................: 500 min=500 max=500
vus_max........................: 500 min=500 max=500
We can configure this tests by making some changes to build_tools/load_generator/site_navigation.js:
import http from 'k6/http';
import ws from 'k6/ws';
import { sleep, group, check } from 'k6';
export let options = {
vus: 500,
duration: '15m'
};At the top of the file we can set the number of Virtual Users (vus) and the duration.
If your machine is struggling to run the test with 500 users you can try lowering the value to 50 and going from there.
If you head back to your Grafana dashboard you won't see anything exciting just yet. The system needs a few seconds to update.
Our Prometheus server will get updates from the services at regular updates, so we will see updated values every 15 seconds or so.
Once the test has been running for a few minutes the dashboard should explode into life.
Now when you make changes to Varcade Games you can test them under load!