Re: [wsrp-coord] Fault handling with handleEvents

[Rich Thompson <richt2@us.ibm.com>]

I agree this is an area that still needs
development. As to your questions:

a. The Producer is required to process
the events in the order they are received. The sending of an array is simply
an optimization over receiving each of them individually. The Consumer
is not required to dispatch events in the order they are received as it
may want to apply logic that reorders the events, inserts ones it generates
itself or even decides to not distribute a particular event.

b. I think the question about whether
all events should be processed or the first fault encountered returned
is a nontrivial one. I would tend toward having the Producer process all
the events and have a means in the return to indicate faults encountered
and whether or not processing was aborted.

c. The requirement is that the events
be processed in the order received. I think it might be a stretch to claim
that can be parallelized. I also suspect that most platforms do not require
portlet developers to write re-entrant code ...

Rich

Subbu Allamaraju <subbu@bea.com>

10/19/2004 10:54 AM

To	wsrp-coord@lists.oasis-open.org
cc
Subject	[wsrp-coord] Fault handling with handleEvents

I would like to discuss if we need to be more specific
about fault 
handling  of handleEvents.

Problem: Unlike performBlockingInteraction, the Producer processes one
or more events during handleEvents and any fault returned from the 
Producer may vary from implementation to implementation.

Scenario: A Producer receives a batch of events via handleEvents. Of 
these, the first event requires state changes, but the Consumer sent a
readOnly flag. The second event requires some security permissions not
allowed for the current user. Whether the Consumer receives a 
StateChangeRequired fault or AccessDenied fault depends on the order 
Producer processes these events.

My questions:

a. Is the Producer required to process the events in the order the 
Consumer supplied those events? Note that we do not require Consumers to
dispatch events in the order they were fired.

b. Should the Producer process both events and return two faults (as 
errors in normal output, as in destroyPortlets)? This may sound bizarre,
but I would like to bring it up for the sake of argument since 
handleEvents may be considered as a multi-input operation like 
destroyPortlets.

c. Is the Producer allowed to process incoming events concurrently? We
don't specify anything about it currently, but shouldn't we?

Regards,

Subbu

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