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Re: Fast SCP
Hanno Klein / Deutsche Börse Systems <>
31 Jul 2008 10:06AM ETRolf,
I have a related question. Is there a way to send a new message without having sent a new template definition, i.e. if I add a field to my message, is there a way for the receiver to ignore that new field until he receives a new template definition from me, perhaps by appending it to the end of my message and having a placeholder in my initial template definition? Or is it a strict requirement to always send a new template definition prior to sending a message for it.
Thanks,
Hanno.
> I was maybe a bit terse.
>
> By using immutable template ids (in the short term) you can relax the
> requirements on synchrony between template definitions and messages
> using template ids. As a receiver, you still need a new template
> definition before you can decode a message with the new template id, but
> the existing definitions don't change (within a time window).
>
> This allows for a lower overhead template distribution solution, which
> is what Dimitry was asking about, I think.
>
> An example; Let's assume you have a template named "foo/1" where 1 is
> the version of the template. Further let's assume the Template Name
> "foo/1" is associated with the Id 7. Now, if you want to modify this
> template (extend or change), you can create "foo/2" which differs in
> some aspect from "foo/1" and, depending on other Ids in use your first
> unused Id is 27, so you associate the name "foo/2" with the id 27.
>
> Now receivers may see different representations of a message type.
> Template id 7 will still refer to the old layout and id 27 will be
> unknown until receivers see / retrieve the definition for id 27. The
> important difference is that you can relax strict ordering as id 7 is
> immutable for some period of time before it may be reused. Not seeing
> the new definition of id 27 can be detected.
>
> You still need a level of synchronization between templates and messages
> in order to consume messages with newly created templates, but you don't
> need a strict ordering; new definitions can be sent out earlier as there
> is no (short-term) change to the meaning of an existing template.
>
> There needs to be additional synchronization if several sources are
> allowed to allocate template ids, but that is a separate issue.
>
> /Rolf
Fast SCP Dimitry London / Morgan Stanley 30 Jul 2008 10:16PM ET Re: Fast SCP David Rosenborg / Pantor Engineering AB 31 Jul 2008 3:28AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 31 Jul 2008 6:17AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 31 Jul 2008 9:05AM ET Re: Fast SCP
Hanno Klein / Deutsche Börse Systems 31 Jul 2008 10:06AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 31 Jul 2008 10:15AM ET Re: Fast SCP Greg Orsini / Cameron Systems 31 Jul 2008 11:44AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 1 Aug 2008 2:06AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 1 Aug 2008 2:39AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 1 Aug 2008 3:13AM ET Re: Fast SCP Hanno Klein / Deutsche Börse Systems 1 Aug 2008 3:33AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 1 Aug 2008 3:57AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 1 Aug 2008 4:10AM ET Re: Fast SCP Rolf Andersson / Pantor Engineering 1 Aug 2008 3:06AM ET Re: Fast SCP David Rosenborg / Pantor Engineering AB 1 Aug 2008 6:28AM ET Re: Fast SCP Jacob Northey / The LaSalle Technology Group 1 Aug 2008 8:21AM ET Re: Fast SCP David Rosenborg / Pantor Engineering AB 1 Aug 2008 9:33AM ET Re: Fast SCP Greg Orsini / Cameron Systems 1 Aug 2008 10:01AM ET Re: Fast SCP David Rosenborg / Pantor Engineering AB 1 Aug 2008 10:16AM ET Re: Fast SCP Greg Orsini / Orc Software w/CameronFIX 1 Aug 2008 10:32AM ET Re: Fast SCP David Rosenborg / Pantor Engineering AB 1 Aug 2008 10:58AM ET Re: Fast SCP Jean-Marie Sulmont / RTS 31 Jul 2008 10:19AM ET Re: Fast SCP Jean-Marie Sulmont / RTS 31 Jul 2008 10:41AM ET Re: Fast SCP David Rosenborg / Pantor Engineering AB 31 Jul 2008 11:10AM ET Re: Fast SCP Dimitry London / Morgan Stanley 7 Aug 2008 10:53PM ET
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