Re: [jetty-users] Sequential pushing with HTTP/2

[Simone Bordet <sbordet@xxxxxxxxxxx>]

Hi,

On Wed, Feb 4, 2015 at 10:40 AM, Jeroen van der Hooft
<jeroen.vanderhooft@xxxxxxxxxxxxxx> wrote:
> Hello Simone and Greg,
>
> Thank you for your response. I understand that a new stream is created and
> assigned to each of the pushed resources, and that there is no sequential
> requirement from the HTTP/2 point of view. However, in a use case where
> video segments are pushed (e.g. as soon as they are available in a live
> stream scenario), consecutive segments should be pushed in the right order.

Why you want to *push* video segments ?
Streaming chunks of them normally would be much simpler and order preserving.

> I made sure this is the case by checking if there are no active, open push
> streams before calling the push function in HTTPTransportOverHTTP2. Of
> course, it would be nice to know if there are other ways to achieve this
> behaviour. I was considering a priority based mechanism at one point, could
> you elaborate on why this could lead to flaws from a server point of view?
>
> Also, I was wondering if there is a way to cancel a started, open push
> stream? Let's say the server is pushing a large resource A, and logic
> dictates that at one point it is better to stop sending this resource and
> move on to resource B? As far as I observed, streams are only cancelled if a
> timeout exception occurs (default is 15s), but there is not yet a
> possibility to cancel a stream from e.g. the HTTPTransportOverHTTP2 class.

Cancelling a stream can be done using stream.reset(...).

However, I would reconsider using the push mechanism to stream data to
the client in a controlled fashion.
The push mechanism has not been designed for such use case.

-- 
Simone Bordet
----
http://cometd.org
http://webtide.com
http://intalio.com
Developer advice, training, services and support
from the Jetty & CometD experts.
Intalio, the modern way to build business applications.