It is currently difficult for screen reader users to directly navigate
to poll options. I spoke to a screen reader user, he suggested to make
the poll question title a h2 element so users can directly jump to it.
To ease setup some changes required in the nginx config for load
balancer setup are prepared here. They do not harm non-loadbalancer setups.
The changes in the system startup scripts are mandatory
The idea is to run a loadbalancer node which maps each BBB node to a
path. That way each user gets only one gUM permission query for a
cluster. The loadbalancer node only serves the html5 client, each BBB
node will serve its own API and handle the websockets for freeswitch and
bbb-webrtc-sfu.
Configuring a cluster setup
===========================
* let bbb-lb.example.com be the loadbalancer node
* let bbb-01.eaxmple.com be a BBB node
Loadbalancer
------------
On the loadbalancer node add an nginx configuration similar to this one
for each BBB node:
```
location /bbb-01/html5client/ {
proxy_pass https://bbb-01.example.com/bbb-01/html5client/;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "Upgrade";
}
```
BBB Node
--------
On the BBB node add the following options to
`/etc/bigbluebutton/bbb-web.properties`:
```
defaultHTML5ClientUrl=https://bbb-lb.example.com/bbb-01/html5client/join
presentationBaseURL=https://bbb-01.example.com/bigbluebutton/presentation
accessControlAllowOrigin=https://bbb-lb.example.com
```
Add the following options to `/etc/bigbluebutton/bbb-html5.yml`:
```
public:
app:
basename: '/bbb-01/html5client'
bbbWebBase: 'https://bbb-01.eaxmple.com/bigbluebutton'
learningDashboardBase: 'https://bbb-01.eaxmple.com/learning-dashboard'
media:
stunTurnServersFetchAddress: 'https://bbb-01.eaxmple.com/bigbluebutton/api/stuns'
sip_ws_host: 'bbb-01.eaxmple.com'
presentation:
uploadEndpoint: 'https://bbb-01.eaxmple.com/bigbluebutton/presentation/upload'
```
Create the following unit file overrides:
* `/etc/systemd/system/bbb-html5-frontend@.service.d/cluster.conf`
* `/etc/systemd/system/bbb-html5-backend@.service.d/cluster.conf`
with the following content:
```
[Service]
Environment=ROOT_URL=https://127.0.0.1/bbb-01/html5client
```
Change the nginx `$bbb_loadbalancer_node` variable to the name of the
load balancer node in `/etc/bigbluebutton/nginx/loadbalancer.nginx` to
allow CORS requests:
```
set $bbb_loadbalancer_node https://bbb-lb.example.com
```
Prepend the mount point of bbb-html5 in all location sections except
from the `location @html5client` section in
`/etc/bigbluebutton/nginx/bbb-html5.nginx`
```
location @html5client {
...
}
location /bbb-01/html5client/locales {
...
}
```
