Which Is More Efficient To Send WebSocket Updates With A MySQL Database Change

I'm currently experimenting with WebSockets in a bid to reduce / remove the need for constant AJAX requests in a potentially low bandwidth environment. All devices are WebSocket co

Solution 1:

If you use websockets, you should use notifications from client. That's one of their main use cases.

If you're worried about inconsistencies due to connection dropping or something changing in-between, you could implement a system similar to HTTP ETags, where client would send a hash code that you can respond on server side if there is a conflict in updating.

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Update: I guess I understood your initial issue a bit wrong. If I understand your use case correctly: you are sending database updates from a client and after that all connected clients need to be updated. In that case, I think server should send the update messages after DB updates have been done, so I agree with solution 4. I am assuming here that your websocket server is the same server running PHP and doing the DB updates.

However, depending on your use case, client should still send a hash value on the next request identifying its "view of the world", so you would not be doing identical updates multiple times if a connection gets broken.

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Update 2: so it was now understood that you indeed use a separate, standalone websocket server. Basically you have two different web servers on the server side and are having an issue on how to communicate between the two. This is a real issue, and I'd recommend only using one server at a time - either take a look at using Apache websocket support (experimental and not really recommended) or migrating your php scripts to the websocket instance.

Neither PHP or Apache was really build with websockets in mind. It is quite easy to set up a standalone websocket server using only PHP, but it might not be so easy then to migrate the rest of the PHP stack to it if the code is relying on Apache/web server on. Apache websocket support also is hardly optimal. For a real websocket solution, unfortunately, best practice would be using a technology that is built for it from the ground up.

Solution 2:

The better answer is to send notification through Server side when database is updated by PHP script, so that script have to add options of web sockets to directly send notification to all web socket clients registered.

User send content->Php script process content and save data according to true condition->check database is updated by checking return of mysql_query/other alternative->if true than use web-socket and send notification to all users

now this is more easy/handy/bandwidth saver.