3 Replies Latest reply on Dec 9, 2008 12:52 PM by Andy Taylor

    netty http integration update

    Andy Taylor Master

      The basic http implementation we have would not work over a clever firewall, this is because it is not a true 1 - 1 mapping between request and response. To solve this we could do the following.

      The client send can will only change slightly. Since Http 1.1 supports request pipelining we should be able to send requests without waiting for a response, so the order could be req1 req2 req3 res1 res2 res3. The spec does say the following however:

      Clients SHOULD NOT pipeline requests using non-idempotent methods or non-idempotent sequences of methods (see section 9.1.2). Otherwise, a premature termination of the transport connection could lead to indeterminate results. A client wishing to send a non-idempotent request SHOULD wait to send that request until it has received the response status for the previous request.


      But I think it should be ok for our usage. The client will also need to send a 'bogus' request when idle for n seconds to make sure the connection isn't closed.


      The server cannot send an unsolicited response to a client but *must* send a response to every request.This should work as follows.

      The server does not send anything directly to the client, instead it keeps a list of 'Pending packets'. When the server receives a request it will initiate a response. any pending packets will be wrapped up in a single response and sent*. If there are no pending responses then the server will wait for a configurable amount of time for a pending message to arrive or send a bogus response, this is again to keep the connection alive.

      *wrapping up all pending packets into a single response will require a copy so theres an overhead, it may be better just to send back a single packet at a time but I'll need to test this to see. It all depends how many actual requests vs responses there are.

        • 1. Re: netty http integration update
          Andy Taylor Master

          Ive just checked in the latest netty http integration changes. for every request there is now a matching response and no responses are sent unsolicited. Ive added an acceptor config, (commented out), and a connector config and matching connection factory.
          Ive run the performance tests which gave reasonable results, about 30% slower on my machine.

          • 2. Re: netty http integration update
            Tim Fox Master

             

            "ataylor" wrote:
            Ive just checked in the latest netty http integration changes. for every request there is now a matching response and no responses are sent unsolicited. Ive added an acceptor config, (commented out), and a connector config and matching connection factory.
            Ive run the performance tests which gave reasonable results, about 30% slower on my machine.


            30% slower than straight TCP transport? If so, that's pretty good :)

            • 3. Re: netty http integration update
              Andy Taylor Master

               

              30% slower than straight TCP transport? If so, that's pretty good :)


              yes, if the jms lab was set up this would be a good time to get some proper figures.