Is above still an issue with http2/3?

edit: From the article: To workaround the limitation you have to use HTTP/2 or HTTP/3 with which the browser will only open a single connection per domain and then use multiplexing to run all data through a single connection.

No, if you can enable TLS and HTTP/2|3, you are only technically using a single browser connection, onto which multiple logical connections can be multiplexed.

I think the article calls this out. There is still a limit on the number of logical connections, but it's an order of magnitude larger.

You can get around that limit using domain sharding, although it feels a bit hacky.

Can the tabs share a background worker that would handle that?

You can use https://www.npmjs.com/package/broadcast-channel which creates a tab leader, no need for a background worker

Edit: of course you could use: https://caniuse.com/sharedworkers but android does not support it. We migrated to the lib because safari took its time… so mobile was/is not a thing for us

Here's the chrome android issue for Shared Workers. Add your voice if it is something you need

https://issues.chromium.org/issues/40290702

just use a service worker to share state, you would be much better off doing this anyways. saves a ton and is performant.

I think you need a SharedWorker for that rather than a service worker https://developer.mozilla.org/en-US/docs/Web/API/SharedWorke...

A service worker would work fine; the connection would be instantiated from the SW and each window/worker could communicate with it via navigator.serviceWorker.

That doesn't work because browsers have duration limits on ServiceWorkers:

https://github.com/w3c/ServiceWorker/issues/980#issuecomment...

Also unfortunately Chrome doesn't keep SharedWorker alive after a navigation (Firefox and Safari do):

https://issues.chromium.org/issues/40284712

Hopefully Chrome will fix this eventually, it really makes it hard to build performant MPAs.

In my experience, as long as a controlled window is communicating with the SW, the connection will remain alive.

Shared workers (inexplicably) dont exist on Android Chrome

https://issues.chromium.org/issues/40290702

Is that true if you are using HTTP/2?

Nope. That's only a problem with HTTP/1.1

Yes, but the limit is different (usually much higher) and negotiated, up to maximum SETTINGS_MAX_CONCURRENT_STREAMS (which is fixed at 100 in Chrome, and apparently less in IOS/Safari.)

HTTP 2/3 doesn't have they limitation.

For HTTP 1, simply shard the domain.

just one tab use SSE and others use storage event.