We have a carline checkout system, where school users:
Release coordinators Teachers Parents use app to check-in to app and app sends real-time message on school uniquely created group so that all receive that parent has arrived, now release those students. To achieve real-time link we integrated azure webpub sub in our app. What we do is when parent/teacher/release-cordinators log into app we create one group per school and so that anything happens on their group all connected devices of this particular schools gets the message.
We are experiencing a strange issue where some of the clients dont receive live updates/messages. Here's my server side code that creates unique url for each client by binding into its school uuid. When each client logs in it gets its unique url and linked with its related group.
app.get('/negotiate', async (req, res) => {
let userId = req.query.id;
if (!userId) {
res.status(400).send('missing user id');
return;
}
let accessTokenRules = [`webpubsub.joinLeaveGroup.${req.query.uuid}`, `webpubsub.sendToGroup.${req.query.uuid}`];
let token = await serviceClient.getClientAccessToken({ userId, "expirationTimeInMinutes": 1440, roles: accessTokenRules});
res.json({
url: token.url
});
});
Later, this is how i send and receive from client side app:
const socket = new WebSocket(urlReceivedAbove, 'json.webpubsub.azure.v1');
socket.onopen = (evt) => {
// when one client socket gets open i send a join group request to school group so that it start receiving/sending on that node
socket.send(JSON.stringify({
type: 'joinGroup',
group: uuid, // same uuid of school so that it is in same group
dataType: "json",
data: {"methodName": "joiningGroup", "payLoad": ""}
}));
};
socket.onmessage = (data) => {
// further processing
}
Issue we are having when more than 200 people connected on one school group, some of the connected clients missed messages. Can we fix this or have some workaround on it?
I checked on azure help they say this protocol json.reliable.webpubsub.azure.v1 can be used as well.
Please help or advise, we need reliable message delivery on each connected client.
