Alan -
from my point of view there are a couple of advantages
introducing the
concept of a service container (at
least for WSRP):
- for WSRP all services are of the same type, so handling them
(life cycle,
invokation framework on the server,
addressing) will be the same. In that
case it is much
easier to handle the request centrally at one single access
point.
- a portal might expose a large number
of portlets. If there was no
container the service
would need an entry point (e.g. soap servlet) for
each
of the portlets. This is not only difficult to setup but may also
consume a lot of resources (depending on your app
server)
- conceptually a portlet is something that
runs inside a portlet (that
manages access, lifetime
etc) . So it makes sense to adpot this model to
the
remote case by introducing a service container.
Best regards
Carsten Leue
-------
Dr. Carsten Leue
Dept.8288, IBM Laboratory B�blingen , Germany
Tel.: +49-7031-16-4603, Fax: +49-7031-16-4401
|---------+---------------------------->
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| Alan
Kropp |
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<akropp@epicentri|
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c.com> |
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| 05/24/2002 01:32
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AM
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| Please respond
to|
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| Alan
Kropp |
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>---------------------------------------------------------------------------------------------------------------------------------------------|
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To: "'Eilon Reshef'"
<eilon.reshef@webcollage.com>, "'Michael Freedman'"
<Michael.Freedman@oracle.com>, "'Gil
Tayar'"
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|
<Gil.Tayar@webcollage.com>
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cc: wsia@lists.oasis-open.org,
wsrp@lists.oasis-open.org
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| Subject:
RE: [wsrp][wsia][wsrp-wsia joint interfaces][Draft Spec
0.43]crea
teEntity/createTemplate/createPortlet
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Mike,
Along the lines of Eilon's question, I'd like to have a
better
understanding as to what the WSRP Producer
Container is for. I confess to
not being
well-informed on the motivation for introducing this concept in
the early interfaces/protocols discussions. My hope has
been that it is
entirely a WSRP-specific construct,
and therefore not something that needs
to be accounted
for in the joint interface. But I'm not convinced one way
or the other, yet.
In the interests of furthering this discussion, if you could
run down the
main points behind the container, for
both groups, I think it would be
beneficial.
I think Mike's outline of the lifecycle interfaces from a
"pure" WSRP
perspective, in relation to Gil's and
Rich's latest rev of the joint
interface
specification, represents the clearest illustration yet of the
"gap" we need to close. This is good progress.
Alan
-----Original
Message-----
From:
Eilon Reshef [mailto:eilon.reshef@webcollage.com]
Sent: Thursday, May 23, 2002
3:36 PM
To: 'Michael
Freedman'; 'Gil Tayar'
Cc: wsia@lists.oasis-open.org; wsrp@lists.oasis-open.org
Subject: RE: [wsrp][wsia][wsrp-wsia
joint interfaces][Draft Spec
0.43]createEntity/createTemplate/createPortlet
Mike,
Per the tension you mentioned,
and your previous e-mail with the
"Container" interfaces (C1-C4).
This is a question that Rich
referred to as "Heterogeneous versus
Homogeneous" services. The question is
whether the "container"
behavior should be an explicit part of the interface (as you
suggested in C1-C4 = "heterogeneous") or
can be implicit in the
interface by providing different "services" (in the WSDL sense), each
representing a separate
portlet type (= "homogeneous").
Why do you feel that WSRP needs
the heterogeneous service? Couldn't a
single container/server provide
different services for different
portlet types, and use WSDL techniques
(mainly, URL paths) to
differentiate between the different portlets?
Eilon
-----Original Message-----
From: Michael Freedman [mailto:Michael.Freedman@oracle.com]
Sent: Thursday, May 23, 2002 5:51 PM
To:
Gil Tayar
Cc:
wsia@lists.oasis-open.org; wsrp@lists.oasis-open.org
Subject: Re: [wsrp][wsia][wsrp-wsia joint interfaces][Draft
Spec
0.43]createEntity/createTemplate/createPortlet
I
don't think we want to give up so quickly on this. As I
think all calls (after createEntity) need to be passed the
entity handle -- and would find each to be unnatural if we
defined they took an optional "bind" key. Also, I don't think
entities are WSRP exclusive things. Rather I think the tension
is
WSRP needs (generic) container model while many components
will
be happy running as standalone services. Personally, I
wonder if we will end up with two APIs -- one for service
simple and one for service container -- much like I depict in
the
e-mail sent earlier describing different component types
needing to be modeled. Though containing by and large the same
API
the difference is the need for createEntity and passing the
return handle in all subsequent operations -- i.e. getFragment,
etc.
-Mike-
Gil
Tayar wrote:
In the interest of sanity and progress, I have broken up
Rich's, Michael's, Monica's and Eilon's emails into four
subjects - "Shared Transient Information", "Persistent
Information Scope",
"createEntity/createTemplate/createPortlet", "session and
entity handles", and "Property lists". This email will
deal with createEntity/createTemplate/createPortlet, and
the relevant quotes from the emails and my reply to them:
Rich wrote:> Presuming the 2nd case to get dropped
relative to the previous set of
> emails, I would propose this section call out how we
will refer to these
> things throughout the remainder of the document/API. In
particular, I would
> suggest:
> Session Information - This is carried
opaquely in
the interface as a
> "sessionID".
> => goes away
> Persistent Information - This is
carried opaquely
in the interface as
> a "handle".> > Rather than
"Manifestation", I
would propose using "Entity" to describe the
> thing from which markup may be requested. I think it
has the right level of
> opacity (Consumer has no idea what kind of entity it
is) while carrying
> appropriate semantics (a thing that may be interacted
with). Using these
> terms, there was also an open question at the end of
our last call related
> to whether there were both persistent and transient
entities ... > > If we are going to support explicit
lifecycle for both of these, I would
> propose:
> handle createEntity(handle,
propertyValues)
> sessionID createSession(handle,
propertyValues)
Michael wrote:> 1) createEntity (aka createTemplate). In
WSRP we have discussed requiring
> consumers register with a producer to "activate" it.
Registration returns an
> 'activation' handle used in subsequent calls to
identify the consumer. How can
> we account for this with the createEntity (and other)
APIs? I really, really,
> really, don't want this to be an property value. Also
what is the actual
> intent of these property lists? Gil implies they are
persistence presets. If
> so should we have a separate list parameter that allow
the consumer to further
> qualify the Entity being created? I.e. in WSRP
portlets aren't the direct
> producer -- they are managed/contained by the producer.
We will want to use
> the createEntity call to create/be tied to these
subtypes -- hence need someway
> to qualify it in the call. Finally, are we assuming
the service never wants to
> programmatically authorize this operation? If not,
don't we need to pass User
> identity and roles as well?> > 2) destroyEntity (aka
destroyTemplate). Since we seem to want to support
> creating new entities from existing one's do we want to
support cascading
> delete? If not we likely should support bulk deletes.
[Note: should we
> consider bulk create as well for import/export/publish
purposes?] As with
> create entity the consumer ID should be passed.Eilon
wrote (and I condense...):[...]> Would you find the
following, radically simplified, suggestion for an
operation> name intrusive:> createPortlet> Along those
lines, a portal would call the operation createPortlet,
would get back a > (persistent) portletID and then
(optionally) call createSession with the portletID.[...]>
2. The ability to create a persistent key seems to be
only under the scope of > WSRP and not under WSIA. WSIA
supports a persistent key to create sessions and > to
subsequent operations, but wouldn't probably deal with
how they are created> and management (with all the
associated issues that are well described in Mike's>
latest summary). Hence, the motivation to use a
portal-specific name.So now Gil writes:It seems that
Michael, Eilon, and myself believe that the
createEntity/Template/Portlet operation is particular to
WSRP (Rich, I even remember adding the "templateKey"
thingie as a shot in the dark to where WSRP is going - it
seems the shot missed!).I suggest then, dropping this
from the joint interface subcommitee, and leaving it in
the hands of the WSRP. Having said that, we must be able
to support some type of connection between the
template/entity/portlet and the "session handle", so what
I propose is that the createSession/Instance operation
(outlined above) will accept an unspecified "bindingKey",
i.e.:sessionHandle/ID =
createSession/Instance(bindingKey).The "bindingKey" will
be an opaque string to be defined either by the WSIA
service, or defined by specs above WSIA (i.e. WSRP). One
can argue that this is similar to JDBC's "connection URL"
(in getConnection) which is an opaque string specified
when "connecting". WSRP could also use it to specify the
"sub-service/portlet" of the container, if WSRP decides
to go the heterogenous.My suggestion is to drop the
createEntity/Template/Portlet, and leave:sessionHandle =
createSession(bindingKey) [bindingKey is an opaqueString,
which will be used in the future by WSRP binding
specifications]getMarkup/performAction....(sessionHandle,
...) [i.e. all operations within the session will receive
the sessionHandle]destroySession(sessionHandle)And, as
Michael suggested, resolve timeout and implict session
creation and deletion issues ASAP.(I specifically dropped
the "propertyList" arguments as they are not the issue
here, but that doesn't mean that I don't support them).
Gil TayarWebCollage
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