OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

 


Help: OASIS Mailing Lists Help | MarkMail Help

wsrp message

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [Elist Home]


Subject: RE: [wsrp] [wsia] [wsrp-wsia joint interfaces] agenda for Tuesday 11June



My comments are embedded in [CL]  tags.


Best regards
Carsten Leue

-------
Dr. Carsten Leue
Dept.8288, IBM Laboratory B÷blingen , Germany
Tel.: +49-7031-16-4603, Fax: +49-7031-16-4401



|---------+----------------------------->
|         |           Eilon Reshef      |
|         |           <eilon.reshef@webc|
|         |           ollage.com>       |
|         |                             |
|         |           06/11/2002 09:37  |
|         |           PM                |
|         |           Please respond to |
|         |           Eilon Reshef      |
|         |                             |
|---------+----------------------------->
  >---------------------------------------------------------------------------------------------------------------------------------------------|
  |                                                                                                                                             |
  |       To:       "'Alan Kropp'" <akropp@epicentric.com>, wsia@lists.oasis-open.org, wsrp@lists.oasis-open.org                                |
  |       cc:                                                                                                                                   |
  |       Subject:  RE: [wsrp] [wsia] [wsrp-wsia joint interfaces] agenda for Tuesday 11 June                                                   |
  |                                                                                                                                             |
  |                                                                                                                                             |
  >---------------------------------------------------------------------------------------------------------------------------------------------|



Alan,

Comments below, with <ER>

I'll follow up with a related question in a subsequent e-mail

Eilon

-----Original Message-----
From: Alan Kropp [mailto:akropp@epicentric.com]
Sent: Tuesday, June 11, 2002 3:05 PM
To: 'Eilon Reshef'; Alan Kropp; wsia@lists.oasis-open.org;
wsrp@lists.oasis-open.org
Subject: RE: [wsrp] [wsia] [wsrp-wsia joint interfaces] agenda for Tuesday
11 June

      Hi Eilon,

      It seems to me the Consumer still doesn't really need a say in how
      the Producer implements the search service runtime model.  It's true
      that if the Producer creates all of these transient entities, there
      is the issue of when it is "safe" to destroy them.  Transient
      entities don't have an inherent lifecycle, but the sessions which
      talk to them do...so, when these sessions have timed out, the
      Producer is able to determine that a transient entity is no longer a
      party to any active session.  Would it be valid to say that the
      Producer, at that point, may assume the transient entity is stale and
      destroy it?

      <ER> I would think so </ER>
      [CL] I would agree as well, only that it is not the producer but the
      consumer that creates the transient entities. [CL]

       I guess this is a variation on reference counting/GC that Java
      developers are already familiar with.

      <ER> yes, except that reference counting is possible in a closed
      environment, whereas "guesswork" (i.e., timeouts ;-) is the option
      that will be used in practice </ER>
      [CL] Garbage collection cannot really be done cleanly in such a
      distributed environment. Java's "Mark & Sweep" only works if the
      system knows all objects (not the case for WSRP) and reference
      counting suffers from possible cycle generation. I assume that the
      concept of timeouts for transient entities will work best here (maybe
      combined with reference counting to give hints on the lifetime, but
      that's an implementation detail). [CL]

      I don't think it's unrealistic to expect the Producer to employ
      intelligence like this to efficiently manage its entities.

      <ER> I would assume that transient entities would be implemented as
      or within sessions, as you suggested so this would be taken care by
      the infrastructure </ER>

      Alan


            -----Original Message-----
            From: Eilon Reshef [mailto:eilon.reshef@webcollage.com]
            Sent: Tuesday, June 11, 2002 11:36 AM
            To: 'Alan Kropp'; wsia@lists.oasis-open.org;
            wsrp@lists.oasis-open.org
            Subject: RE: [wsrp] [wsia] [wsrp-wsia joint interfaces] agenda
            for Tuesday 11 June

            Alan,

            I think that one example scenario is a search results page, say
            for hotels, that dynamically displays multiple maps - a map for
            each hotel found.

            Assuming that maps are remote services, and assuming that the
            number of results is dynamic, the Consumer needs to create
            multiple copies of the map service. If we allow the Producer to
            determine the persistence state of those maps, that would mean
            that someone will have to take care of the lifetime of those
            maps. The Consumer can't, because the page may be gone without
            the Consumer never knowing about it (the user closes the
            browser window). The Producer can't, because it can't tell
            whether the Consumer has stored a reference to those maps as
            part of a design-time description of a user page.

            Is that along the lines of what you were looking for?

            Eilon
                  -----Original Message-----
                  From: Alan Kropp [mailto:akropp@epicentric.com]
                  Sent: Tuesday, June 11, 2002 2:18 PM
                  To: 'wsia@lists.oasis-open.org';
                  'wsrp@lists.oasis-open.org'
                  Subject: RE: [wsrp] [wsia] [wsrp-wsia joint interfaces]
                  agenda for Tuesday 11 June



                  I find that the question of a Consumer creating a
                  persistent vs. a transient
                  entity to be a little troubling.


                  Isn't the Consumer primarily interested in getting a
                  handle to an _entity_
                  (be that transient or persistent), and then using that
                  handle to direct
                  subsequent requests to?


                  Could we not consider persistence and transience to be
                  entirely Producer
                  concerns?  I understand from the sequence in the spec
                  (pp. 6-8) that the
                  only supporting scenario for the Consumer calling
                  "createTransientEntity" is
                  out of an effort to maximize the efficiency of the
                  conversation with the
                  Producer.  This is a worthy goal, of course, but the
                  Producer should
                  advertise its interaction behavior in the meta-data,
                  right?  Presumably the
                  Producer uses the meta-data to hint to the Consumer the
                  way(s) the Consumer
                  SHOULD structure invocation requests efficiently.


                  I'd love to see some more convincing scenarios to support
                  pushing the
                  persistent/transient aspect of the conversation out to
                  the Consumer.
                  Otherwise, I'd love even more to limit our specification
                  to a single
                  "createEntity" call.


                  Alan





                  -----Original Message-----
                  From: Carsten Leue [mailto:CLEUE@de.ibm.com]
                  Sent: Tuesday, June 11, 2002 2:19 AM
                  To: Gil Tayar
                  Cc: thomas klein6; 'wsia@lists.oasis-open.org';
                  'wsrp@lists.oasis-open.org'
                  Subject: RE: [wsrp] [wsia] [wsrp-wsia joint interfaces]
                  agenda for
                  Tuesday 11 June






                  Gil -


                  1-3: the consumer MUST explicitly create entities
                  (transient or
                  persistent). It can decide to create sessions explicitly
                  if it wants to
                  share them amongs entities, otherwise it can let the
                  producer create
                  sessions on the fly.
                  4: the decision to have multiple entities per session is
                  up to the consumer
                  who make this choice based on the producer's metadata.
                  e.g think of
                  portlets that form a shop together. These would want to
                  share a session
                  with each other. But the consumer could decide to have
                  two shops of the
                  same type on the same page. Then there would be two
                  sessions and only the
                  consumer could know what portlet shares what session.
                  5: The consumer should create a session before issuing a
                  getFragment call.
                  The entity is created whenever necessary.
                  6: A Session is a bucket that holds some data (physically
                  on the provider)
                  and times-out after a while. A transient entity is a
                  remote portlet that
                  does not store any data in a DB.


                  Hope that helped.


                  Best regards
                  Carsten Leue


                  -------
                  Dr. Carsten Leue
                  Dept.8288, IBM Laboratory B÷blingen , Germany
                  Tel.: +49-7031-16-4603, Fax: +49-7031-16-4401






                  |---------+---------------------------->
                  |         |           Gil Tayar        |
                  |         |           <Gil.Tayar@webcol|
                  |         |           lage.com>        |
                  |         |                            |
                  |         |           06/11/2002 09:28 |
                  |         |           AM               |
                  |         |           Please respond to|
                  |         |           Gil Tayar        |
                  |         |                            |
                  |---------+---------------------------->

                  >
                  ---------------------------------------------------------------------------

                  ------------------------------------------------------------------|

                    |
                  |
                    |       To:       Carsten Leue/Germany/IBM@IBMDE
                  |
                    |       cc:       "'wsia@lists.oasis-open.org'"
                  <wsia@lists.oasis-open.org>,
                  "'wsrp@lists.oasis-open.org'"
                  <wsrp@lists.oasis-open.org>, Thomas|
                    |        Klein6/Germany/IBM@IBMDE
                  |
                    |       Subject:  RE: [wsrp] [wsia] [wsrp-wsia joint
                  interfaces] agenda
                  for Tuesday        11 June
                  |
                    |
                  |
                    |
                  |

                  >
                  ---------------------------------------------------------------------------

                  ------------------------------------------------------------------|







                  Carsten, could you clarify some things for me?


                  1. If sessions and entities are orthogonal, what SHOULD
                  the Consumer do?
                  2. SHOULD it create a transient entity _and_ a session?
                  3. MUST it do so?
                  4. Who gets to decide whether there are multiple entities
                  per session or
                  multiple sessions per entities?
                  5. When SHOULD a Consumer create a session and when a
                  transient entity?
                  6. What _is_ a session, logically? What _is_ a transient
                  entity?


                  Gil


                  -----Original Message-----
                  From: Carsten Leue [mailto:CLEUE@de.ibm.com]
                  Sent: Tuesday, June 11, 2002 08:45
                  To: Alan Kropp
                  Cc: 'wsia@lists.oasis-open.org';
                  'wsrp@lists.oasis-open.org'; thomas
                  klein6
                  Subject: Re: [wsrp] [wsia] [wsrp-wsia joint interfaces]
                  agenda for
                  Tuesday 11 June






                  Alan - some first thoughts


                  1. the general concept is that entities (transient or
                  persistent) and
                  sessions are orthogonal. There might be mulitple entities
                  per session and
                  (at least for persistent entities) multiple sessions per
                  entity. An example
                  for the first case would be that entities share session
                  data within  the
                  same user request. An example for the second case are
                  portlets on a common
                  page (group page) that are access simultaneously by
                  multiple users.
                  A transient entity differs from a persistent entity in
                  that its data does
                  not persist and its lifecycle is coupled with the session
                  life cycle.


                  2. Eilon pointed out in a comment to the interface
                  proposal that batch
                  processing is already part of SOAP. I was not aware of
                  that and will look
                  it up until the call.





                  Best regards
                  Carsten Leue


                  -------
                  Dr. Carsten Leue
                  Dept.8288, IBM Laboratory B÷blingen , Germany
                  Tel.: +49-7031-16-4603, Fax: +49-7031-16-4401






                  |---------+---------------------------->
                  |         |           Alan Kropp       |
                  |         |           <akropp@epicentri|
                  |         |           c.com>           |
                  |         |                            |
                  |         |           06/11/2002 01:54 |
                  |         |           AM               |
                  |         |           Please respond to|
                  |         |           Alan Kropp       |
                  |         |                            |
                  |---------+---------------------------->


                  >
                  ---------------------------------------------------------------------------

                  ------------------------------------------------------------------|

                    |
                  |
                    |       To:       "'wsrp@lists.oasis-open.org'"
                  <wsrp@lists.oasis-open.org>,
                  "'wsia@lists.oasis-open.org'"
                  <wsia@lists.oasis-open.org>        |
                    |       cc:
                  |
                    |       Subject:  [wsrp] [wsia] [wsrp-wsia joint
                  interfaces] agenda for
                  Tuesday 11  June
                  |
                    |
                  |
                    |
                  |


                  >
                  ---------------------------------------------------------------------------

                  ------------------------------------------------------------------|







                  I think we'll have plenty of discussion around the merged
                  document Rich and
                  Carsten put together.


                  The two main issues I see that have arisen on the email
                  lists are:


                  1.  What is the difference between transient entities and
                  sessions, and is
                  there enough of a distinction to warrant including both
                  in the
                  specification?


                  2.  There are efficiency concerns around the use of
                  arrays in the method
                  signatures, basically to enable batched requests for
                  network efficiency.





                  Call-in numbers:
                   USA Toll Free Number: 877-718-0936
                   USA Toll Number: +1-712-923-6878
                   PARTICIPANT PASSCODE: 563151





                  Alan





                  ----------------------------------------------------------------

                  To subscribe or unsubscribe from this elist use the
                  subscription
                  manager: <http://lists.oasis-open.org/ob/adm.pl>








                  ----------------------------------------------------------------

                  To subscribe or unsubscribe from this elist use the
                  subscription
                  manager: <http://lists.oasis-open.org/ob/adm.pl>








                  ----------------------------------------------------------------

                  To subscribe or unsubscribe from this elist use the
                  subscription
                  manager: <http://lists.oasis-open.org/ob/adm.pl>


                  ----------------------------------------------------------------

                  To subscribe or unsubscribe from this elist use the
                  subscription
                  manager: <http://lists.oasis-open.org/ob/adm.pl>









[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [Elist Home]


Powered by eList eXpress LLC