how to make sure the http response was delivered?

Question

To respond a http request, we can just use return "content" in the method function.

But for some mission-critical use cases, I would like to make sure the http 200 OK response was delivered. Any idea?

Answer 1

The HTTP protocol doesn't work that way. If you need an acknowledgement then you need the client to send the acknowledgement to you.

Or you should look at implementing a bi-direction socket (a sample library is socket.io) where the client can send the ACK. If it is mission critical, then don't let it be on just http, use websockets

Also you can use AJAX callbacks to gather acknowledgment. One way of creating such a solution would be UUID generated for every request and returned as a part of header

$ curl -v http://domain/url
....
response:

X-ACK-Token: 89080-3e432423-234234-23-42323

and then client make a call again

$ curl http://domain/ack/89080-3e432423-234234-23-42323

So the server would know that the given response has been acknowledge by the client. But you cannot enforce automatic ACK, it is still on the client to send it, if they don't, you have no way of knowing

PS: The UUID is not an actual UUID here, just for example shared as random number

Answer 2

Take a look at Microsofts asynchronous server socket.

An asynchronous server socket requires a method to begin accepting connection requests from the network, a callback method to handle the connection requests and begin receiving data from the network, and a callback method to end receiving the data (this is where your client could respond with the success or failure of the HTTP request that was made).

Example