RE: [wsrp-coord] Should we design in support for out-of band even ts?

From
Tamari, Yossi <>
Date
2003-08-06T09:20:37+00:00
ID
Thread
RE: [wsrp-coord] Should we design in support for out-of band even ts?
Title: 

See 
inline.

   

    Yossi,

  
-----Original Message-----
From: Andre Kramer 
  [mailto:]
Sent: Wednesday, August 06, 2003 
  11:27 AM
To: 
Subject: RE: 
  [wsrp-coord] Should we design in support for out-of band even 
  ts?

  
I would say that coordinating which portlets are involved 
  in eventing/updates (and which require re-display) is in scope of SC 
  [page / fragment level invalidation is not].
[Yossi Tamari] I agree that the spec should 
  enable portlets that received events to send new markup. I think this 
  should be managed much like an interaction. I do not think we should develop a 
  special cache invalidation mechanism for 
  eventing.  

  
 

  
For out-of-band, we should make sure we have clear processing 
  phases that can be used to demarcate out of band signalling. Possibly 
  some sort of virtual clock?
[Yossi 
  Tamari] I would like to see a proposition on how this can work. I 
  currently fail to see the value of demarcating something that may 
  have happened a long time ago, and is outside the spec to begin 
  with. 

  
If this means adding a new stage where 
  all portlets are polled, I would strongly object. Otherwise, since 
  portlets are only called after an interaction with them, or an in-band event 
  they subscribed to (including their state being "written"), this would be 
  extremely not deterministic, and not 
  useful. 

  
 

  
regards,

  
Andre

  
    
-----Original Message-----
From: Tamari, Yossi 
    [mailto:]
Sent: 06 August 2003 
    09:04
To: 
Subject: RE: 
    [wsrp-coord] Should we design in support for out-of band even 
    ts?

    
Hi 
    Mike,

    
 

    
I 
    am afraid I didn't get the "Able" joke. You'll have to explain at the 
    F2F...

    
 

    
I 
    think you just moved from discussing Cross Portlet Coordination to 
    discussing cache invalidation, which is out of the scope of this 
    committee. The charter of this committee (if we had 
    one...) is to define coordination between portlets, not messages 
    from the portlet to the consumer.

    
While I do not object to defining a set of events a portlet 
    MAY send that MAY be meaningful to some consumers, I 
    do not think this should be the focus of this committee, and definitely 
    not to discuss things like caching.

    
 

    
I 
    am not saying we should preclude WSRP ever supporting OOB events, I am 
    saying we should take it out of the scope of discussions, and focus 
    on our deliverable.

    
What we are doing in this SC is going to be difficult enough to 
    get everybody to agree to, we should not even go in the direction of 
    defining extra consumer behaviors except delivering events/state 
    changes.

    
 

    
    Yossi. 

    
      
-----Original Message-----
From: Michael Freedman 
      [mailto:]
Sent: Wednesday, August 06, 
      2003 2:13 AM
To: 
      
Subject: Re: [wsrp-coord] Should 
      we design in support for out-of band even ts?

Yossi, 
      should I call you Able?  I agree with Rich that there are 
      producers/portlets which aren't dormant between consumer requests -- for 
      example portlets fronting syndication servers.  At some point in time 
      we will need to address how these portlets can communicate changes to its 
      consumer.  Piggybacking on the next consumer request won't always be 
      acceptable.  An easy example is an InvalidateMyContent event -- the 
      above syndication server may need to send an invalidate event to the 
      consumer when information has been updated so the consumer knows to 
      rerender the portlet on subsequent requests.  If this type of 
      out-of-band mechanism didn't exist the portlet would have to put a dummy 
      action in its content [like a refresh me button] just so piggybacking 
      could occur.  

That being said, I think its a medium/low 
      priority to define out-of-band eventing for 2.0.  By this I think we 
      should focus first on clearlying defining an in-band capability [which I 
      am not yet convinced is event based].  If we solve this soon enough 
      then we can tackly out-of-band in 2.0 -- otherwise post 2.0.  Though 
      the actual priority is subject to change depending on how we choose to 
      define invalidation with respect to events.  My second expectation is 
      that out-of-band eventing [when defined] must be an optional consumer 
      capability.  I.e. portlets will have to deal with running with 
      consumers that don't provide such a service.
    
       -Mike-

Tamari, Yossi wrote:

      
        
        
I think the best guidance we can provide is to 
        ignore this case, implicitly saying that we do not think it should be 
        used...

        
I agree that the _applications_ behind the 
        portlets maybe receiving and sending OOB events, but I do not think 
        portlets should do that. Portlets have a very clear life cycle, and in 
        my view when they are not explicitly called by the container (and 
        consumer) they should be dormant (in a sense they only exist during the 
        request cycle. Between requests it's just their state that persists, 
        just like servlets, ASP pages, etc.).

        
 

        
    Yossi.

        
          
-----Original Message-----
From: Rich Thompson [mailto:]
Sent: 
          Monday, August 04, 2003 7:28 PM
To: 
Subject: 
          Re: [wsrp-coord] Should we design in support for out-of band 
          events?

This is 
          equivalent to saying that it is up to each implementation to decide 
          how out-of-band items get reflected into the WSRP interactions. My gut 
          instinct says this is where we will likely end up, but I think we 
          would do a disservice to the community-at-large if we don't at least 
          consider the implications related to out-of-band events and possibly 
          provide some guidance. 

Rich Thompson 

          
            
            

              

              Alejandro Abdelnur <> 
                
Sent by:  

                
08/04/2003 11:48 AM 
              

                      
                
      
                  To:        Rich 
                Thompson/Watson/IBM@IBMUS 
        cc:       
                 Alejandro Abdelnur <>, 
                 
                
        
                Subject:        Re: [wsrp-coord] Should we 
                design in support for out-of band 
          events?

I'm not sure we should we care about out-of-band events, 
          unless we 
consider pushing them through WSRP calls. In other 
          words, making them 
in-band.

Alejandro

On Monday, 
          August 4, 2003, at 06:19  AM, Rich Thompson 
          wrote:

>
> I think it is important when considering 
          this question to start with 
> the realization that out-of-band 
          events will occur. We need to 
> consider how to reflect these 
          into the interactions between the WSRP 
> actors (Portlet, 
          Producer, Consumer and End-User) when out-of-band 
> 
          communication between at least some of these actors is not in 
          place.
>
> To consider:
> 1. Portlet/Producer 
          receives an out-of-band event that may cause a 
> change in its 
          state.
> 2. Consumer receives an out-of-band event (i.e. not a 
          user 
> interaction) that it wishes to distribute to various 
          Portlets. Does 
> distributing coordination info (events or 
          state) always result in the 
> aggregation of markup?
> 3. 
          User-agent receives an event. Is any communication arising from in 
          
> this case just a virtual user-interaction (i.e. the other 
          WSRP actors 
> view it as a user-interaction)?
>
> 
          Rich Thompson