How to tell an HTTP client to limit parallel connections?

Question

I've got a very feeble web server. The crypto handshaking involved in opening an https: connection takes 2-3 seconds. That would be fine if a browser opened a single connection and then sent a series of requests on that connection to load the various elements on a page.

But that's not what browsers do. They all seem to open whole handful of connections (often as many as 8-10) and try to load all the page's elements in parallel. That turns what would be a 3-4 second page load time (using a single connection) into a 20-30 second page load time. Even with plaintext http: connections, the multi-connection page load time is slower than the single-connection load time, but not by as large a factor.

Some browsers have user-preference settings that limit the max number of simultaneous connections to a single server (IIRC the RFCs suggest a max of 4, but most browsers seem to default to a max of 8-16).

What I really need is an HTTP header or meta-tag or something that I can use to tell clients to limit themselves to a single connection.

I haven't been able to find such a thing, but I'm hoping I've overlooked something...

Answer 1

That will only go so far. Suppose you tell web browsers "no more than 3 connections", then get hit by 30 nearly simultaneous, but separate clients. Then you still wind up allowing up to 90 connections.

There should be a parameter in your web server's config file to limit the number of simultaneously active threads or processes. It's been a long time for me, and you don't mention what brand of server you are
running, but ISTR that Apache has/had such parameters.

Answer 2

There's an Apache module called mod_limitipconn that does just what you are asking. I've never used it and can't vouch for it. I'm not aware of anything like this for other servers like Nginx.