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From Rafael Schloming <rafa...@redhat.com>
Subject Re: [java] 0-10 proposal
Date Wed, 08 Aug 2007 11:02:31 GMT
Rupert Smith wrote:
> So, is there a command to open or create a session, and then another to
> attach it to a channel.
> + a command to open/create a channel on a connection?
> All I've really seen of 0-10 so far, is the amqp.0-10-preview.xml, that has
> been checked in on trunk. That doesn't have a 'channel' class in it (yet?).

In 0-10 the term channel refers to the physical transport for a session, 
and although at any given point a session may only be attached to a 
single channel, over it's lifespan a session may be connected to 
multiple channels.

AMQP assumes that channels are purely a mechanism for multiplexing a 
connection, so logically when a connection is established, the whole 
range of permitted channels (0 to the negotiated MAX) are ready and 
available for use.

The only thing you can actually do to a channel in AMQP without a 
session being attached to it is to either open or resume a session, so 
at the moment at least there is no need for a channel class.


> Rupert
> On 08/08/07, Robert Godfrey <rob.j.godfrey@gmail.com> wrote:
>> In 0-10...
>> A TCP connection has many channels... (same as 0-8)
>> A Session may have a lifetime that exceeds the lifetime of a single
>> connection.
>> A session may be attached to a (single) channel.
>> It may then be detached, and later re-attached to a separate channel on
>> the
>> same or a different connection.
>> After a Session has been detached from a channel (or after the session has
>> been clsed) a different session may attach to that channel.
>> Hope this helps,
>> Rob
>> On 08/08/07, Rupert Smith <rupertlssmith@googlemail.com> wrote:
>>> Hi, I had another look at this code and have another question. I am not
>>> particularly well versed yet with the 0-10 protocol, so this may just be
>>> my
>>> ignorance. Is 'channel' in 0-8 renamed to 'session' for 0-10, and
>>> completely
>>> dropped from the 0-10 protocol? Or does 0-10 have both channels and
>>> sessions?
>>> Reason I ask is because the stub has connection, channel and session.
>>> Sessions are opened on channels. Connection can have many channels, but
>>> session and channel are always tied together 1:1.
>>> Should it be that connection can have many sessions and the session open
>>> method is handled at the connection level?
>>> Rupert
>>> On 18/07/07, Rafael Schloming <rafaels@redhat.com> wrote:
>>>> Here are some stubs I've been working on that describe most of the
>>>> communication layer. For those who like dealing directly with code,
>>>> please dig in. I will be following up with some UML and a higher level
>>>> description tomorrow.
>>>> --Rafael

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