Hi,

I strongly disagree with you explanation. I don’t want to cite the 
specification again. The idea behind a PullPoint and the usage pattern are 
clearly specified in that document and they are different from what you 
explained here. The basic functionality is having an ability a client behind a 
firewall being an able to pull stored messages. This is the first aspect. The 
second aspect is why should PullPoint store every notification (situation) for 
each possible topic bound to the Notification Producer in interset (it is a 
waste of memory or db resources as well as network bandiwth for transfering 
something that will be rejected anyway).

I believe that multiple change requests will arise related to this "issue" in 
the future when more and more people start using PullPoint functionality.

Thanks for your comments anyway.

Regards,

Marjan
 
-----Original Message-----
From: Vinh Nguyen (vinguye2) [mailto:[EMAIL PROTECTED] 
Sent: Friday, July 13, 2007 12:24 PM
To: [email protected]
Subject: RE: PullPoint default (simple) implementation bug

Hi Marjan,
I think that's the correct behavior by design.  A PullPoint is itself a
consumer, too, although its primary responsibility is to cache the
notifications so that clients can request the history of notifications
at any given point in time.  So when you create a PullPoint, it should
automatically subscribe itself for notifications.  Otherwise, it will
never get notifications from the real producer.

Then, for your client to receive notifications from the PullPoint, you'd
have to subscribe to the PullPoint, too.  In this case, the PullPoint
also acts as a "producer".  Or, you don't have to subscribe to it, but
just call various operations directly on it to retrieve the stored
notifications as needed.

If you don't want your PullPoint to automatically subscribe upon
initialization, you can override the Muse implementation.  But, then
you'd have to explicitly subscribe the PullPoint for notifications from
the producer at some point, else it won't get any notifications to
store.


-----Original Message-----
From: Marjan Sterjev [mailto:[EMAIL PROTECTED] 
Sent: Thursday, July 12, 2007 11:17 PM
To: [email protected]
Subject: RE: PullPoint default (simple) implementation bug

Hi Vinh,

That's I'm talking about. When we create a PullPoint, subscription is
automatically created and only this automatically created one is bound
to the PullPoint. If we use NotificationProducerClient in order to
subscribe to the PullPoint using filtering, we are creating the second
subscription and this one is not bound the PullPoint in the current
implementation.

Thanks

Marjan Sterjev

 
-----Original Message-----
From: Vinh Nguyen (vinguye2) [mailto:[EMAIL PROTECTED]
Sent: Thursday, July 12, 2007 8:56 PM
To: [email protected]
Subject: RE: PullPoint default (simple) implementation bug

Hi Marjan,
I haven't used the PullPoint implementation yet, but for your question
about the filter, I think you would pass that in the Subscribe
operation.  So the subscription does the filtering on the "server" end,
instead of the PullPoint "consumer" end.  Of course, you can still take
advantage of the notification consumer framework to apply further
filtering on the consumer end.  The PullPoint itself can just act as a
storage.


-----Original Message-----
From: Marjan Sterjev [mailto:[EMAIL PROTECTED]
Sent: Thursday, July 12, 2007 2:35 AM
To: [email protected]
Subject: PullPoint default (simple) implementation bug

Hi,

 

I didn't get any response on my question about PullPoint working
example, so I was investigating and digging the source code in the mean
time (it is always about time).

 

I added the required WSDL modifications for PullPoint and
CreatePullPoint port types and I was able to create PullPoint. However
GetMessages operation returns no messages at all. Why?

 

The Muse PullPoint simple implementations didn't work without
modifications and recompilation of the code. The problem is with the
class org.apache.muse.ws.notification.impl.SimplePullPoint in the method
accepts().

 

public boolean accepts(NotificationMessage message)

    {

        EndpointReference subEPR = message.getSubscriptionReference();

        //return subEPR != null && getSubscription().equals(subEPR);

        return subEPR != null &&
subEPR.equals(getSubscription().getEndpointReference());

    }

 

I commented the wrong line and added the correct line comparing objects
of the same type, i.e. getSubscription()  should be replaced with
getSubscription().getEndpointReference()).

 

The Muse PullPoint implementation mechanism is rather strange. The
specification (wsn-ws_base_notification-1.3-spec-os.pdf page 25) says:
The intended pattern of use is that a Subscriber or other party creates
a PullPoint through the factory interface, and then uses it as the
ConsumerReference in one or more Subscribe requests. The actual consumer
then pulls Notifications from the PullPoint. 

 

I was following this pattern, i.e. I created PullPoint and after that I
was using the returned ConsumerReference in a separate Subscribe
request. I found that this way we get 2 subscriptions. 

 

We can see that in the class
org.apache.muse.ws.notification.impl.SimplePullPointCreation
subscription is automatically created when the PullPoint is created. Is
this correct?
Subscription on what? The Simple implementation produces subscription
using
PublishAllMessagesFilter:

 

public Filter getFilter()

{

        return PublishAllMessagesFilter.getInstance();

 }

 

Ok, someone can argue that we can write our own implementations that
will support filtering. However the question is how we can supply filter
parameters? The interface org.apache.muse.ws.notification.Interface
PullPointCreation has method createPullPoint(), i.e. there are no
arguments at all.
 
Am I missing something?
 
Regards
 
Marjan

 

 

 

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