I agree we are trying to address multiple
use cases with one mechanism, but I see this as a good thing. Should we have a
mechanism for every use case of every feature?
I believe the way to handle this is to add
metadata info on the export operation, where the consumer tells the producer
the expected usage of the “export package”. I also do not object to
defining a lease duration on the export package, if we decide to do it
elsewhere in the spec.
Since handles are opaque and can contain
anything (with only a size limit), I don’t see how this helps the claim
you state.
Yossi.
From: Andre
Kramer [mailto:andre.kramer@eu.citrix.com]
Sent: Monday, July 26, 2004 2:47
PM
To: interfaces
Subject: RE: [wsrp-interfaces] New
Import Export document
Right, the use case
explicitly does not require passing data through the consumer. In fact, I'm
arguing that it must not require data to be passed through the consumer. This
allows a real-world "no data will be exported in any form"
requirement to be asserted. This rules out the technical option of encrypting
the data.
The technical option of
passing "by reference" is currently ruled out by the lack of lifetime
scoping on the export/import. Data can not be held indefinitely by the
producer (the Union) just so that it can be
imported or re-imported at some arbitrary later time. A releaseExportedState(),
called by the consumer, would address this (as would a one-time only import /
possibly with use-by data).
But copyPortlets() solves
the use case much more simply (for me) as it is easy to show that no data has
passed through the consumer (only handles). How does the producer know when to
export encrypted state and when to export by reference? Seems we are tying to
address two use cases with one mechanism.
Regards,
Andre
From: Rich
Thompson [mailto:richt2@us.ibm.com]
Sent: 26 July 2004 12:13
To: interfaces
Subject: RE: [wsrp-interfaces] New
Import Export document
I don't see how the use case requires passing of data through the
Consumer. The portlet gets to decide what is bundled into the
"exportedState" with the inherent flip side of being required to
process that data when instantiated as a new portlet later. Whether this is a
reference or some opaque (possibly encrypted) data becomes a portlet decision.
Why is this flexibility a bad thing?
Rich
|
Andre Kramer
<andre.kramer@eu.citrix.com>
07/26/2004
05:35 AM
|
|
To
|
interfaces <wsrp-interfaces@lists.oasis-open.org>
|
|
cc
|
|
|
Subject
|
RE: [wsrp-interfaces] New Import Export document
|
|
I'm asserting that such use cases exist in the
real world. Passing any data, even if encrypted, through the consumer should
not be required for "install" of a portlet application.
Regards,
Andre
From: Tamari, Yossi [mailto:yossi.tamari@sap.com]
Sent: 26 July 2004 09:36
To: interfaces
Subject: RE: [wsrp-interfaces] New Import Export document
Hi Andre,
I still don't understand what is the issue with passing the
data through the consumer, if it is encrypted (note that what I mean by
encrypted is so that only the producer can decrypt it, so it is really opaque
to the consumer).
Yossi.
From: Andre Kramer
[mailto:andre.kramer@eu.citrix.com]
Sent: Monday, July 26, 2004 10:58 AM
To: Tamari, Yossi
Subject: RE: [wsrp-interfaces] New Import Export document
The use case involves a (new) union member installing the Union's application into her company portal as a wsrp
portlet. My claim was simply that no data should be "imported" (and exported)
through the company portal in the install process even if encrypted. The
details of how the union portlet ended up with state in the first place was
just to prevent any claim of the portlet being a "stateless" UI tier.
Regards,
Andre
From: Tamari, Yossi
[mailto:yossi.tamari@sap.com]
Sent: 25 July 2004 10:29
To: 'interfaces'
Subject: RE: [wsrp-interfaces] New Import Export document
Hi Andre,
I do not understand your final comment (the Trade Union
example). Are you suggesting that the portlet uses the customization as cache?
If this is the case, it should either encrypt it or make sure it is not
exported. Since it is a cache it will just "refill".
It is true that a portlet can put anything in the
customization information, even an encryption key, but I think this is misuse.
Anyway, this is a moot point, since encryption solves the
problem.
Yossi.
From: Andre Kramer
[mailto:andre.kramer@eu.citrix.com]
Sent: Friday, July 23, 2004 1:19 PM
To: 'interfaces'
Subject: FW: [wsrp-interfaces] New Import Export document
Ooops - I failed to reply to the list. See comments
below.
Regards,
Andre
-----Original Message-----
From: Tamari, Yossi [mailto:yossi.tamari@sap.com]
Sent: 23 July 2004 11:03
To: 'Andre Kramer '
Subject: RE: [wsrp-interfaces] New Import Export document
Hi Andre,
Did you exclude the rest of the group from your answer
intentionally?
<ak>sorry</ak>
The problem with the first solution you suggest (the
consumer releases...) is that in the second use case the consumer does not
necessarilly know when this is the situation, at least not for a very long
time.
By the way, two dangling references are created here:
portlet and registration.
The leasing solution could work here, but it could
also work with Mike's approach. Exported portlets just become one more leased
resource.
I still have some conceptual problems with leasing in
general, though, because it basically says: "things will stop working, but
at least you know when".
I would not be opposed to adding an optional
releaseExportedState, with metadata whether this is really needed.
in the second use case copyPortlets is not really
atomic, since it needs to be called twice - once on export to create a
snapshot, and once on import to create a new clone. Since the second could fail
(the lease expired?), the probelms are all still there.
<ak> Agree, but the first use case is covered in
one operation. </ak>
The copyPortlets also requires more from the producer:
It can't differntiate between a "frozen" copy and a "live"
one, which prevents it from some serious optimizations that can be done if you
know a portlet is never going to be executed.
In the end, I think the second use case requires an
export/import mechanism. It can be "emulated" using the copyPortlets
operation, but that has no advantage. The advantage of the export/import
operations is that at least in some cases the producer will want to export the
state to the consumer (exportData), and other then network traffic I see no
problem with doing this. The security/privacy concerns people have been voicing
are unbased in my opinion for a number of reasons:
1. Any user specific info that the portlet had has
first gone, in plain text, through the consumer (this is how WSRP works), so
the user must trust the portal he is using.
2. Usualy exported portlets are not including
personalization, just configuration (the use case document says so), and this
is normally not private info.
3. The producer can very easily encrypt the data
before sending it, at least in the case of one physical producer, which is the
only case copyPortlets works for.
4. The consumer can set up a mechanism of
private/public key encryption to insure only "safe" consumers will be
able to import the package.
<ak> A portlet can compute and store data based
on consumer mediated user info that the consumer should not see, as it
communicates with back-end services. E.g. A worker uses the company portal to
drive a Trade Union Portlet that has a back-channel to the union database but
caches affiliation data in the customization. One can program portlets to be
stateless so that export presents no problems but do we want to mandate this?
Some portlets are just not going to be exportable. </ak>
Yossi.
-----Original Message-----
From: Andre Kramer
To: Tamari, Yossi
Sent: 7/23/2004 9:43 AM
Subject: RE: [wsrp-interfaces] New Import Export document
The dangling copy you identify should be deleted by
the consumer when
the imports are over.
In the export/import scheme there is no way to signal
to the producer
that no further imports are going to occur. This makes it problematic
for the producer to export state "by reference" (e.g. storing handles
or
a filename in the export blob) as the producer has no way to clean up.
Mike's proposal would be an extension of copyPortlets
if it added a
"releaseExportedState()" operation. But then we still have
reliability
problems of potentially failing operations that copyPortlets() does not
have as it is an atomic operation (rather an a separate export and
import operation). Of course, I'm assuming that deleting portlets
reliably will be addressed by Leasing so there are no dangling (portlet)
copies!
Regards,
Andre
_____
From: Tamari, Yossi [mailto:yossi.tamari@sap.com]
Sent: 22 July 2004 18:13
To: interfaces
Subject: RE: [wsrp-interfaces] New Import Export document
The problem you seem to be ignoring is the second use
case, of exporting
once and importing multiple times. The way to solve this with
copyPortlets is:
The exporting consumer clones the portlet on export,
and then the
importing consumer clones again on import. But then we have the
"dangling" copy, which we can't delete, since it may be imported
again,
and the leak is the same as in Mike's proposal if exportData is used to
store the handle.
The point I am trying to make is that Mike's proposal
is an extension of
copyPortlets, with no extra cost, but with more flexibility.
Yossi.
_____
From: Andre Kramer [mailto:andre.kramer@eu.citrix.com]
Sent: Thursday, July 22, 2004 8:05 PM
To: interfaces
Subject: RE: [wsrp-interfaces] New Import Export document
A clone of the portlets to "freeze" them
perhaps? (either within a
registration or to a new registration).
Regards,
Andre
-----Original Message-----
From: Tamari, Yossi [ mailto:yossi.tamari@sap.com
<mailto:yossi.tamari@sap.com> ]
Sent: 22 July 2004 17:02
To: interfaces
Subject: RE: [wsrp-interfaces] New Import Export document
But is the state still the same as it was when
copyPortlets first
called? How do you do this?
Yossi.
-----Original Message-----
From: Subbu Allamaraju [ mailto:subbu@bea.com <mailto:subbu@bea.com> ]
Sent: Thursday, July 22, 2004 6:42 PM
To: interfaces
Subject: Re: [wsrp-interfaces] New Import Export document
I think copyPortlets() is replayable as long as the
source registration
is still valid and the source portlets are valid in that registration.
Subbu
Tamari, Yossi wrote:
> Hi Subbu,
>
> I think the use case document talks only about b. (quote: "the above
> scenario assumes that each consumer environment [development, stage,
> production] is talking to the same physical producer").
>
> However, the second use case is not supported by the copyPortlets
> operation, if I understand the operation correctly, since the import
> operation should be "replayable", so one export should create a
> "package" that can be imported many times at other consumers.
>
> Yossi.
>
>
> -----Original Message-----
> From: Subbu Allamaraju [ mailto:subbu@bea.com <mailto:subbu@bea.com> ]
> Sent: Thursday, July 22, 2004 5:57 PM
> To: interfaces
> Subject: Re: [wsrp-interfaces] New Import Export document
>
> In the use cases document, I think we need to clearly distinguish
> between consumer-side migration issues from producer-side migration
issues.
>
> a. A Consumer customized some portlets of Producer. Producer is going
> from staging to production, while Consumer remains the same. There is
a
> need to move portlet customizations across the Producers.
>
> b. The Consumer is moving from staging to production, while the
Producer
> remains the same. In this case, the new Consumer wants to retain the
> same portlet customizations in a new registration context.
>
> If we are talking about (b), it is still not clear why a
copyPortlets()
> like operation would not address it.
>
> Subbu
>
>
> Rich Thompson wrote:
>
> >
> > I agree that the burden of transferring portlets from one
registration
> > to another belongs at the Producer. I'm not sure what about the
> > export/import proposal changes that. If it relates to the use
of a
POP
> > handle on the import, I actually disagree that the Consumer
should
need
> > to do that dereference ... it ought to be the portletHandle
> > corresponding to the exportedState.
> >
> > As to the use cases (see
> >
>
http://www.oasis-open.org/apps/org/workgroup/wsrp-interfaces/download.ph
p/5614/Portlet%20Transport.htm
<http://www.oasis-open.org/apps/org/workgroup/wsrp-interfaces/download.p
hp/5614/Portlet%20Transport.htm> )
>
> > that seem to favor an approach that captures a snapshot of a
portlet's
> > state:
> > - Use case #1 refers to capturing a snapshot of a development
system
> > that is then pushed to the production system while development
> > continues. I think it unreasonable to require the development
system to
> > remain static for whatever duration is involved in deploying
the
> > snapshot on however many production systems it impacts.
> > - Use case #2 makes snapshots even more important as the timing
for
> > deployment of the new Consumer in
unknown. Certainly development
wants
> > to continue on these systems as well.
> >
> > That said, import/export is not the only way to capture a
snapshot.
> > However, it is important that the
solution we develop support the
> > underlying use cases.
> >
> > Rich
> >
> >
> > *Subbu Allamaraju <subbu@bea.com>*
> >
> > 07/22/2004 09:41 AM
> >
> >
> > To
> > Rich Thompson/Watson/IBM@IBMUS
> > cc
> > interfaces
<wsrp-interfaces@lists.oasis-open.org>
> > Subject
> > Re: [wsrp-interfaces] New Import Export
document
> >
> >
> >
> >
> >
> >
> >
> >
> > I agree with Andre's suggestions, as it correctly puts the
burden
on the
> > producer to transfer portlets from one registration context
another
> > another without exposing any state.
> >
> > > The main difference I see between such an operation
and the
proposed
> > > export/import is that the operation references the
current state
of a
> > > portlet while export/import proposal captures a
snapshot and
then
> looks
> > > to recreate it. For some of the use cases, I think
this is an
> important
> > > difference.
> >
> > Could you elaborate this in the context of the use case? The
use
case is
> > about letting certain customized portlets be used from another
consumer.
> > Import/export may be one particular way of solving it, but not
the
only
> > option, I think.
> >
> > > I would suggest we not get involved in scenarios
involving a
> migration
> > > of the Producer as well. How would a Consumer, in
general, learn
the
> > > following scenario relative to Portlets exported
from Producer1:
> > > - PortletA may be imported
to Producer 2, but not Producer3
> > > - PortletB may be imported to Producer3, but not
Producer2
> > > - None of the exported portlets may be imported to
ProducerN
> >
> > Have we captured these with our use cases for this problem?
> > Cross-producer import/export seems to be a new use case not
discussed so
> > far.
> >
> > > With the opaque nature of exportedState, Producers
can easily
store
> > > enough information to allow automation of such
cross-Producer
(same
> > > vendor implementation) imports. Out-of-band
communication to the
> > > Consumer of which portlets
a different Producer is able to
import
> seems
> > > appropriate for our protocol (at least until other
deployment
> protocols
> > > get defined that we could leverage).
> > >
> > > Rich
> > >
> > >
> > > *Andre Kramer <andre.kramer@eu.citrix.com>*
> > >
> > > 07/22/2004 06:45 AM
> > >
> > >
> > > To
> > >
"'Michael Freedman'"
<Michael.Freedman@oracle.com>,
> > interfaces
> > > <wsrp-interfaces@lists.oasis-open.org>
> > > cc
> > >
> > > Subject
> > >
RE: [wsrp-interfaces] New Import Export
document
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > As Exporting / Importing state has privacy and
reliability
issues,
> how
> > > far would the following operation go in covering the
use cases?
> > >
> > > PortletHandle newHandle = copyPortlet(PortletHandle
thePortlet,
> > > RegistrationHandle fromRegistration,
RegistrationHandle
> toRegistration);
> > >
> > > This would normally be called by a wsrp consumer
(e.g. when a
staged
> > > deployment goes live). I've purposely not included
our
> portletState to
> > > show that no data need be passed outside of the
producer(s). Two
> > > producers could pass portlet
data between themselves (using a
> > > proprietary API or the proposed Export/Import
mechanism) if the
> > > registrations are on different producers.
> > >
> > > Regards,
> > > Andre
> > >
> > >
> > >
>
------------------------------------------------------------------------
> > >
> > > *From:* Michael Freedman [ mailto:Michael.Freedman@oracle.com
<mailto:Michael.Freedman@oracle.com> ] *
> > > Sent:* 22 July 2004 01:46*
> > > To:* interfaces*
> > > Subject:* [wsrp-interfaces] New Import Export
document
> > >
> > > I have rewritten the original strawman to define
specific
> import/export
> > > methods. It has been _uploaded to the
Interfaces documents_
> > >
> >
> <
http://www.oasis-open.org/apps/org/workgroup/wsrp-interfaces/download.ph
p/7861/Import_Export2.html
<http://www.oasis-open.org/apps/org/workgroup/wsrp-interfaces/download.p
hp/7861/Import_Export2.html> >.
>
> >
> > > If you want to refer to the old version click
on "Manage" to
the far
> > > right of the document entry. This takes you to
a page where you
> can see
> > > the previous revision(s).
> > > -Mike-
> >
> >
>