users@jax-rs-spec.java.net

[jax-rs-spec users] [jsr339-experts] Re: Server sided use of JAX-RS client API: Valid in which server sided components?

From: Markus KARG <markus_at_headcrashing.eu>
Date: Wed, 27 Jun 2012 19:44:55 +0200

Well, in fact nobody says that it should be forbidden. The question was
whether the spec must explicitly allow it, as opening sockets IS explicitly
forbidden by the Java EE spec already.

> -----Original Message-----
> From: Bill Burke [mailto:bburke_at_redhat.com]
> Sent: Dienstag, 26. Juni 2012 23:57
> To: jsr339-experts_at_jax-rs-spec.java.net
> Subject: [jsr339-experts] Re: Server sided use of JAX-RS client API:
> Valid in which server sided components?
>
>
>
> On 6/26/12 5:41 PM, Jan Algermissen wrote:
> > Hi Markus,
> >
> > On Jun 16, 2012, at 3:50 PM, Markus KARG wrote:
> >
> >> Experts,
> >>
> >> some weeks ago we discussed server sided use of the new JAX-RS
> client API, e. g. to pull information from an external RESTful web
> service.
> >>
> >> As I remember, at least for EJBs (SBs, MDBs) it is forbidden to use
> blocking operations, threading operations, files API and sockets API.
> All this for the sake of stability and security.
> >
> > Yes, this is a good question because it is too easy to assume you
> could just chunk up a larger system into HTTP services and fire calls
> between the services all over the place.
> >
> > In my opinion, serving an HTTP request must not involve an upstream
> HTTP call unless in the case of relatively infrequent requests (e.g.
> order submission) or unless a local cache is very well known to have a
> sufficient hit ration.
> >
> > Turning every user request into a (cascade of) upstream HTTP requests
> is not really what we want. This statement is not as ridiculous as it
> sounds because software architects and consulting firms come up with
> such designs all over the place :-) ... or, well, rather :-(
> >
> > I am not sure how a container could 'enforce' anything here, but IMHO
> HTTP-servers-as-clients is as much a container issue as transactions
> are.
> >
> > Ideas?
> >
>
> So you're saying using the client API within a server should be
> forbidden? We're talking about distributed systems here, not one-off
> Web UIs.
>
> --
> Bill Burke
> JBoss, a division of Red Hat
> http://bill.burkecentral.com
>