Effect of TCP RST on page loading time for Javascript script src tag

I want to deprecate (turn off/not send HTTP responses) for some old HTML & JS code that my clients have installed on their pages. Not all clients can update all of their webpages prior to when we deprecate, but I have the OK to deprecate.

Simple example of what the code can look like:

Cust开发者_如何转开发omer domain, customer.com, has HTML & JS on their pages:

<script src="http://mycompany.com/?customer=customer.com&..."></script>

We are considering configuring our switches to send a TCP RST response on incoming deprecated requests to http://mycompany.com/..., so my question is, are there any side-effects (stall page loading, for example) with the approach of configuring our switches to respond with a TCP RST on the incoming TCP connection? Obviously, I want the least (ie no) impact on a customer's site.

I have to think that RST is a fairly harsh mechanism to not reply to a single request. This request might be one of a hundred resources required to render one of your client pages, and if you tear down the connection, that connection cannot be re-used to request further resources. (See 19.7.1 in the HTTP1.1 RFC: "Persistent connections are the default for HTTP/1.1 messages; we introduce a new keyword (Connection: close) for declaring non-persistence.")

Each new connection will require a new three-way handshake to set up, which might add half a second per failed request to one of the two connections the client is using to retrieve resources from your servers. What is the average latency between your servers and your customers? Multiply that by three to get the time for a new three-way handshake.

If you fail the requests at the HTTP protocol level instead (301? 302? 404? 410?) you can return a failure in the existing HTTP connection and save three-round-trips to generate a new connection (which might also be for a resource that you're no longer interested in serving).

Plus, 410 ought to indicate that the browser shouldn't bother requesting the resource again (but I have no idea which browsers will follow this advice.) An RST-ed resource will probably be re-tried every single time it is requested.