xk6-mqtt

This is a k6 extension using the xk6 system.

❗ This is a proof of concept, isn't supported by the k6 team, and may break in the future. USE AT YOUR OWN RISK!

This project is a k6 extension that can be used to load test Mqtt. Per each connection to Mqtt, many messages can be sent. These messages are an array of strings. There is also a consumer for testing purposes, i.e. to make sure you send the correct data to Mqtt. The consumer is not meant to be used for testing Mqtt under load.

In order to build the source, you should have the latest version of Go (go1.15) installed. I recommend you to have gvm installed.

k6 version

This extension is uptodate with k6 version v0.38.0 (breaking change) previous version is tagged at tag v0.37.0

Build

To build a k6 binary with this extension, first ensure you have the prerequisites:

• gvm
• Git

Then, install xk6 and build your custom k6 binary with the Mqtt extension:

1. Install xk6:

$ go install go.k6.io/xk6/cmd/xk6@latest

2. Build the binary: from latest version

$ xk6 build --with github.com/pmalhaire/xk6-mqtt@latest

3. Build the binary: from source code

git clone github.com/pmalhaire/xk6-mqtt
cd xk6-mqtt
$ xk6 build --with github.com/pmalhaire/xk6-mqtt=.

Run & Test

First, you need to have your Mqtt development environment setup.

For example you can use vernemq

docker run --rm -p 1883:1883 -e "DOCKER_VERNEMQ_ACCEPT_EULA=yes" -e DOCKER_VERNEMQ_ALLOW_ANONYMOUS=on --name vernemq -d vernemq/vernemq

or Mosquitto

docker run --rm --name mosquitto -d -p 1883:1883 eclipse-mosquitto mosquitto -c /mosquitto-no-auth.conf

optional use tls see: https://openest.io/en/services/mqtts-how-to-use-mqtt-with-tls/

docker run -v $PWD/docker_conf/mosquitto:/conf --rm --name mosquitto -p 8883:8883 eclipse-mosquitto mosquitto -c /conf/mosquitto-tls.conf

k6 Test

To use this extension write you test as a js file :

The sample test file does the following.

Creates per VU (concurrent clients) :

• one topic
• one subscribe connection
• one publish connection

Per iteration :

• Subscribe to topic
• Publish to topic messageCount messages
• Read and check message messageCount results

You can run the test using the following command:

# from previously built version
./k6 run --vus 50 --duration 1m examples/test.js
# from source (you need to be in this repo folder) directly for debug
xk6 run --vus 50 --duration 1m examples/test.js

Sample test result output:

          /\      |‾‾| /‾‾/   /‾‾/
     /\  /  \     |  |/  /   /  /
    /  \/    \    |     (   /   ‾‾\
   /          \   |  |\  \ |  (‾)  |
  / __________ \  |__| \__\ \_____/ .io

  execution: local
     script: examples/test.js
     output: -

  scenarios: (100.00%) 1 scenario, 50 max VUs, 1m30s max duration (incl. graceful stop):
           * default: 50 looping VUs for 1m0s (gracefulStop: 30s)


running (1m00.0s), 00/50 VUs, 236183 complete and 0 interrupted iterations
default ✓ [======================================] 50 VUs  1m0s

     ✓ is publisher connected
     ✓ is subcriber connected
     ✓ is sent
     ✓ message received
     ✓ is content correct

     █ teardown

     checks.........................: 100.00%  ✓ 2598013       ✗ 0
     data_received..................: 0 B      0 B/s
     data_sent......................: 0 B      0 B/s
     iteration_duration.............: avg=12.69ms min=104.96µs med=3.44ms max=92.4ms p(90)=44.18ms p(95)=46.17ms
     iterations.....................: 236183   3933.228118/s
     mqtt.received.bytes............: 31196010 519516.746376/s
     mqtt.received.messages.count...: 708549   11799.684355/s
     mqtt.sent.bytes................: 31196010 519516.746376/s
     mqtt.sent.messages.count.......: 708549   11799.684355/s
     vus............................: 50       min=50          max=50
     vus_max........................: 50       min=50          max=50

ROADMAP

• Add examples with events for async functions (k6/events)
• Make subscribe function async
• Update the code to allow multiple event listener or at least clean the singleton
• Allow multiple subscribe calls
• Test https://github.com/goiiot/libmqtt as an alternate client (pprof shows bottleneck in paho client)
• Investigate performance there are string copy made in sync publish function that should not be done