Tinyscale

TLDR: tinyscale is a single file load balancing solution for BigBlueButton that runs on deno.

Depending on your requirements for BigBlueButton and your server capabilities you may need to host more than one instance of BigBlueButton to host meetings for your users. But as soon as you run more than one server you either need to split up servers for different endpoints, let's say one BBB server for Greenlight and another one for moodle, or you install a load balancer that decides for you where new meetings are set up and where users are routed to. If you only use one endpoint for all your meetings you will have to use a load balancer such as scalelite to run more than one BBB instance.

While scalelite is a very good load balancer it also uses a lot of resources and is somewhat complicated to set up (ymmv). tinyscale aims to fill the niche for a lightweight load balancing option that uses very little resources and keeps things as simple as possible.

So, how does it work?

tinyscale offers a unified gateway to your set of BBB servers. Just like BBB you have to give your endpoint your tinyscale address and a secret and on the server side you have to give tinyscale a JSON file with your servers in it. tinyscale then checks to see if it can connect to your BBB servers and wait for incoming calls from your endpoint(s).

If you send a request to tinyscale it checks basically for two things: is there a BBB instance running that has the requested meetingID or recordingID and then redirects your request to that instance. You will from then on communicate directly with that instance.

In case the request is a create call and the meetingID doesn't yet exist tinyscale will pick the next instance from the list of your BBB instances and will create a new room on that instance. The response is then returned to your endpoint.

Apart from that all incoming requests are checked for a valid checksum according to BBB's own API. If an invalid checksum is found you will get an error response.

The load balancing feature is basically a cycle through the available servers with every room creation request where no room could be found on any of the available instances.

Getting started

To get this load balancer to work you need a server that runs Deno. In most cases you should be ok to just run the installer script: https://deno.land/manual/getting_started/installation

Then create a servers.json file like this here:

[
  {
    "host": "http://bbb1.schule.de/bigbluebutton/api",
    "secret": "secret_string"
  },
  {
    "host": "http://bbb2.schule.de/bigbluebutton/api",
    "secret": "secret_string"
  }
]

Now you are ready to start the script. Make sure to have an environment variable called TINYSCALE_SECRET:

TINYSCALE_SECRET=some_secret_string deno run --allow-net --allow-env https://deno.land/x/tinyscale@v2.0.2/main.ts

tinyscale will then run on port 8000 and you will have to set up your reverse proxy so that it can pick up requests. If you prefer a different port you can set one with another env var: PORT 3005

When started, tinyscale will connect to each server and make a single call to check if your configuration is correct. If there is a problem tinyscale will abort. If your configuration works you can start using it in your environment by replacing your existing BBB settings with the new tinyscale url in your endpoints. Make sure to also replace the BBB secrets with your new TINYSCALE_SECRET.

tinyscale has been battle tested to work with NextCloud, Moodle and Mattermost.

Caveats

  • tinyscale does not combine requests like getMeetings. It will return the list of meetings from the current server (i.e. the last one used for creating a room).

MIT Licensed

This project uses BigBlueButton and is not endorsed or certified by BigBlueButton Inc. BigBlueButton and the BigBlueButton Logo are trademarks of BigBlueButton Inc.