Re: Using PUSH to refresh a previously requested resource?

The push promise is an implicit get the server proactively assumes the
client will want to make so it goes ahead and starts sending a response
without waiting for the client.  There really is nothing that says that
pushed resource can't be used for the purpose you describe but it's not
clear what kind of API the user agent may provide,  if any,  for accessing
the pushed stream.  You likely would just treat it like you would any
hanging get and the fact that it's a pushed stream would be completely
transparent.

That said,  there are likely better solutions that would work better, such
as a websocket over http/2 variation.
On Jul 3, 2013 12:45 AM, "Ben Niven-Jenkins" <ben@niven-jenkins.co.uk>
wrote:

> Colleagues,
>
> I've been pondering the use of server push in non-browser environments. As
> currently designed server push is meant for pushing resources associated
> with the originally requested resource. Unless I've missed something it
> doesn't allow for the server to push an updated version of a previously
> requested resource.
>
> What I'm thinking of is something like a webservice where the client is
> regularly polling the server for a resource (e.g. completion status of a
> running 'job') where the server may decide it is advantageous to push a
> refreshed/updated version of the resource to provide a more timely update
> to the client (e.g. as soon as the 'job' completes) rather than waiting for
> the client to next poll for itself.
>
> I read the semantics of PUSH_PROMISE as roughly "based on the request you
> made here are some different resources associated with the one you
> requested that might be useful" but the semantics I think I need are "based
> on the request you made here is an updated version of that resource" or
> possibly (I need to think about it more) "based on a previous request you
> made here is an updated version of that resource 'piggybacked' on a
> response to a request for a different resource".
>
> Am I being overly restrictive in my interpretation of associated and an
> updated resource is in fact 'associated' with the older version of the same
> resource?
>
> The piggybacking of a PUSH for an unrelated resource (i.e. not referenced
> in the requested resource) doesn't appear to be accommodated by the (spirit
> of the) current spec but it's not clear to me if it's actively prohibited
> or just that the current spec wording implies (to me) it is not
> intended/allowed without saying so explicitly.
>
> Thanks
> Ben
>
>
>
>