Title: RE: [wsrp] handleEvent or handleEvents?
Yes, this is what we discussed under issue #02 and #12: Portlets should be able to receive pre-defined failure events. I think you are suggesting also allowing producers to raise these same pre-defined events (or very similar ones)? I missed the discussion on what the problems of handleEvent failures was but your suggestion is a very good way to simplify handleEvents.
Regards,
Andre
-----Original Message-----
From: Richard Jacob [mailto:]
Sent: 14 December 2004 09:37
To: Andre Kramer
Cc: Andre Kramer;
Subject: RE: [wsrp] handleEvent or handleEvents?
Andre, this brings me to an interesting point.
You say that it would be desirable to have portlets receive event handling
failures.
In general I can see this use case and agree to it.
But in our last design (before we removed handleEvents temporary) portlets
never received that information, rather only the Conusmer received them in
the failed events response array.
However, couldn't we regard event handling failures again as events which
are returned with the handleEventsResponse?
This would allow us to get rid of the discussion how we indicate failures,
what the semantics are etc. and these would be delivered to interested
portlets for free.
Mit freundlichen Gruessen / best regards,
Richard Jacob
______________________________________________________
IBM Lab Boeblingen, Germany
Dept.8288, WebSphere Portal Server Development
WSRP Standardization Technical Lead
Phone: ++49 7031 16-3469 - Fax: ++49 7031 16-4888
Email: mailto:
Andre Kramer
<andre.kramer@eu.
citrix.com> To
Richard Jacob/Germany/IBM@IBMDE,
12/14/2004 09:57 Andre Kramer
AM <>
cc
Subject
RE: [wsrp] handleEvent or
handleEvents?
I agree that we can't postulate reliable event or failure notification.
However, best effort delivery of network and event handling failure
indications to interested portlets is still useful as it allows them to
offer alternative user interactions.
Regards,
Andre
-----Original Message-----
From: Richard Jacob [mailto:]
Sent: 13 December 2004 18:38
To: Andre Kramer
Cc:
Subject: RE: [wsrp] handleEvent or handleEvents?
One other important point to me is that we really should understand the
nature of events.
Portlets shouldn't rely on event delivery and thus also shouldn't rely on
correct event processing.
We also do not deliver failure events back to the portlet issuing the
original event (this was the first design we had).
Therefore we might want to ask ourselves what event failures are really for
and who will be doing what with this information.
Key point for me is that we shouldn't try to implement a (relyable)
messaging system based on events, i.e. we shouldn't add any
atomicy,rollback, etc. rules to eventing.
Mit freundlichen Gruessen / best regards,
Richard Jacob
______________________________________________________
IBM Lab Boeblingen, Germany
Dept.8288, WebSphere Portal Server Development
WSRP Standardization Technical Lead
Phone: ++49 7031 16-3469 - Fax: ++49 7031 16-4888
Email: mailto:
Andre Kramer
<andre.kramer@eu.
citrix.com> To
12/13/2004 03:17 cc
PM
Subject
RE: [wsrp] handleEvent or
handleEvents?
Recognizing that event processing occurs in rounds would also help the
presentation. Each round involves a consumer delivering a batch of events
to the producer and optionally receiving back a further batch of events
(and failure events) to process.
Regards,
Andre
From: Rich Thompson [mailto:]
Sent: 13 December 2004 14:10
To:
Subject: Re: [wsrp] handleEvent or handleEvents?
The F2F decision was to drop to handleEvent for now due to the issues
involved in handling faults in the batched case. We should work on these
and seek to restore the nature to a batch operation for the reasons you
list. Basically the solution should respect the current overall design:
1. Portlets are loosely coupled components integrated onto the page by the
Consumer.
2. Events are notifications that something has occurred which other
components may use to impact their own state.
3. There are times when a Consumer will care what failures have occurred
(e.g. for retry purposes)
I think if we agree to these guidelines, then relatively simple solutions
to the failure issues in the batch operation can be designed. Any comments
on these as guidelines before we try and design/debate a solution?
Rich
Andre Kramer
<>
To
12/10/2004 07:06 AM -open
.org
cc
Subject
[wsrp] handleEvent or
handleEvents?
My comment is on the current 2.0 draft, so I am sending it to the TC list,
even though it is specific to coordination. As initially written,
handleEvent is constrained to only deliver a single (IN) event and requires
the consumer to not deliver a second event while the first is being
processed (but multiple events can be returned by a portlet). This seems an
unworkable solution to me because of (1) network latency and (2) event
processing logically occurs in rounds. Should we start with handleEvents
rather than try to discuss a handleEvent?
Regards,
Andre
