Can the HTTP client send a request while receiving the HTTP response?
For example, a client sends HTTP request A to server. Then, the server starts to send HTTP response. Before the client finish to receive HTTP response A, the client sends additional request B. Can it be possible? or Does it follow the HTTP RFC?
I think that above scenario is different from the pipelining. What I know about the pipelining is the scenario that client send multiple request A,B,C then the server response A,B,C consecutively. However, in the above scenario, request B is issued while the processing the response A.
Thank you
With the same connection object you must read the whole response before you can send a new request to the server, because response provides access to the request headers, return type and the entity body, If you send new request before fully reading response, client may get confused with mismatched responses.
Again it totally depends upon client library you using. Library could allow asynchronous requests.
There are concepts like
AsyncTask in android, promis in Angularjs etc.
allow asynchronous request.
Related
I am trying to send a request from client machine to the server A, and receive response from Server A, B, and C. Once A received the request from the Client, it forwards it to Server B, and C. So, after all servers learned about client request, every server will process the request and then respond to the client. In this case, the client will receive many responses. My question is how to send one request for one server and receive many responses for single request. I know that http is not working in this scenario. Is there any suggestions?
Note: I am using Golang.
Thanks.
I was playing around my redis server and tried to hit with the browser. Redis detected it as a Cross Protocol Scripting attack and returned an error in the response's payload. However, when I checked the window's console, it turned out that the request was returned without a status code. So, in such cases what status code should a client assume?
There is no such thing as a response without a status code. Every HTTP response has one, and if you didn't get one it means:
You weren't talking to a HTTP server.
The HTTP server did something it shouldn't.
In each case I would expect your HTTP client to throw some kind of exception but not return a Http Response object.
I'm currently trying to automatically reconstruct an HTTP browsing only with a pcap ( basically it means matching an HTTP reply to the next HTTP requests). Most of the times, it works fine but sometimes a certain url, u, is present in the data of multiple HTTP replies.
For example, if u1 and u2 contains u in their reply data and if the request to u happens after the request to u2, how can I decide if the request to u was caused by u1 or by u2 ? Note that no request to u was made between u1 and u2.
Are there some fields in any network layer that I can use to make this match ?
Thanks!
HTTP runs on top of TCP, which is connection-oriented. You have access to the IP header of the connection used for the HTTP request (client IP/port -> server IP/Port).
HTTP is a command/response protocol, there is 1 response for each request.
So, simply look for an HTTP response immediately following the HTTP request on the same TCP connection (server IP/Port -> client IP/Port).
HTTP is state-less, the connection may be closed between requests without affecting the overall browsing model (closing connections is the required behavior in HTTP 0.9, is the default behavior in HTTP 1.0, and is not the default behavior in HTTP 1.1+), so it is possible for an HTTP response to trigger subsequent requests on new connections, so you need to be ready to handle that. The Connection header in the HTTP request will tell you whether the client is asking for the connection to remain open or not. The Connection header in the HTTP response will tell you whether the server is actually closing the connection or not after sending the response. But even if the server leaves the connection open, that is no guarantee that the client will actually reuse the same connection for later requests to the same server (though it likely will, unless a timeout elapses between requests).
I am creating a Netty Client which sends HTTP request to POST data to server.To increase the performance what i did was using Keep alive Http request(i know that in HTTP 1.1 all requests are keep alive by default, so i am making sure that Connection header is not set to close while sending the Http request) so that it uses the same channel to send the Http Request. Now when i send the Http request to the correct URL,i.e. if i get HttpResponse Status OK in return from server, i am able to send the next Http Request properly but when i send the Http Request for which i get BAD REQUEST or SERVICE UNAVAILABLE or something other than OK then i am unable to send the next request that is the channel future f.success() returned after calling channel.write(request) is false. I am unable to understand why it happens. I have followed the same model of coding as done in HttpSnoopClient example given in netty,
except i have removed the connection:close header & even the client handler is the same as that given in snoop client, also i have am instantiating the bootstrap only once at the starting
I tried getting channelFuture f.cause().getMessage() but it was null it seems
Also, can you SEND any header back? (return headers) when you run a web server?
Or, are headers limited?
Web pages are retrieved using the HTTP protocol. HTTP is text-based. Both, a client requesting and a server responding within a HTTP communication can add custom headers to the HTTP messages. Its up to the communicating parties how to process these. I would assume that an unknown header is dropped silently.