--- In [email protected], "Mike
Glendinning" <[EMAIL PROTECTED]> wrote:
>
> --- In [email protected], Bill de hOra
> <bill@> wrote:
> >
> > If we had a trace on the wire, it would look like a regular HTTP
> > request. There's no embedded method call in the request body (or
> the
> > URL), unless we want to argue that GET is an RPC.
> >
>
> Bill,
>
> Sorry for the late response, but I've been distracted on other things
> for the past couple of days.
>
> I didn't mean to pick on you, but I do see the "RPC is bad" meme
> being parroted quite a lot and not subject to much discussion or
> justification. So I have been looking for an opportunity to prompt
> more discussion. I'm not so sure that RPC is intrinsically bad and
> think that the truth is, as always, somewhat more nuanced.
>
> To explore further and address your points as well as those from
> Stefan and Miran, let's look at some definitions of RPC. From the
> classic paper by Birrell/Nelson [1], we have:
>
> "...it is proposed that [procedure calls] be extended to provide
> for transfer of control and data across a communication network.
> When a remote procedure is invoked, the calling environment is
> suspended, the parameters are passed across the network to the
> environment where the procedure is to execute [...], and the desired
> procedure is executed there." (Section 1.1)
>
> Quite a few years later, a certain student wrote the following in his
> doctoral dissertation [2]:
>
> "What distinguishes RPC from other forms of network-based
> application communication is the notion of invoking a procedure on
> the remote machine, wherein the protocol identifies the procedure and
> passes it a fixed set of parameters, and then waits for the answer to
> be supplied within a return message using the same interface."
> (Section 6.5.2)
>
> By both of these definitions, your code example below is RPC:
>
> resp, content = h.request("http://example.org/people/anne";, "GET")
>
[snip]
>From this POV, we could certainly argue that issuing an HTTP GET
request is RPC per definitions above. After all, the client sends a
request over the network to the server, where the request ultimately
triggers GET's implementation
But here we descend to lower, more
technical details. And perhaps to discussions such as
'request-response style is derivative of RPC style'.
>From the higher planes, where most of the recent RPC-is-bad debates
are being conducted, there is one big differentiator between RPC style
(the, as you said earlier, parroted "bad RPC") and REST style
RESTful interface is uniform and constrained to a fixed number of
methods. Therefore, in its "low-level RPC-ish implementation" you
don't have arbitrary procedure calls flying around, but only a few
uniform ones (which in case of HTTP correspond to implementations of
HTTP verbs).
Regards,
Miran
