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Posted to dev@tuscany.apache.org by ant elder <an...@gmail.com> on 2007/05/18 18:32:28 UTC
CompositeBuilderImpl.createSelfReferences creates a $self$ reference using the service binding
Debugging TUSCANY-1292 it looks like one part of the problem is that
CompositeBuilderImpl.createSelfReferences creates a new self reference for
each service on a component and adds every binding from that service into
the new reference. That results is a JSON-RPC reference provider get used
which seems strange to me but I don't completely understand what the
createSelfReferences is trying to do. Does anyone understand this more and
know if this is the correct behaviour or not?
...ant
Re: CompositeBuilderImpl.createSelfReferences creates a $self$ reference
using the service binding
Posted by Mike Edwards <mi...@gmail.com>.
Raymond,
Comments inline...
Raymond Feng wrote:
> Hi,
>
> Let's look at a use case:
>
> Assuming we have a deployable composite as follows.
>
> <composite ...>
> <component name="MyComponent">
> <service name="MyService>
> <binding.ws .../>
> </service>
> </component>
> </composite>
>
> When this composite is deployed to the SCA domain, then "MyService"
> should be available over the Web Service binding. Let's assume that the
> deployed URI is http://localhost:8080/MyComponent/MyService.
>
> Now it becomes interesting: Is "MyService" available for
> SCADomain.getService(MyService.class, "MyComponent/MyService")? If so,
> which binding should be used?
Yes, the intention is that it is available. The binding that should be
used is (one of) the bindings expressed by the service - in this case
it's the web service binding. The binding should be compatible with the
binding on the reference that wants to use it....
>
> If the answer is yes, I think by the SCA spec, only Web Service binding
> is available to access MyService. Then the service proxy returned from
> SCADomain.getService(...) will be a self reference with a Web Service
> binding and the binding URI should be the SAME as the calculated service
> binding URI, i.e., http://localhost:8080/MyComponent/MyService. (I
> think the binding URI for the self reference is not correctly filled
> today and that's why the $self$ comes into the binding providers' faces).
This is correct according to the SCA spec.
>
> The other option is that if the service doesn't have a SCA binding,
> SCADomain.getService(...) will throw ServiceUnavailableException.
Nope, this should not happen unless the reference demands some different
binding (eg JMS). Even then the exception looks wrong
"IncompatibleServiceException" would be nearer the mark.
Incompatibility could occur for a variety of reasons, incluing interface
mismatch or Intent/Policy incompatibility.
>
> Thanks,
> Raymond
>
> ----- Original Message ----- From: "Matthew Sykes" <sy...@gmail.com>
> To: <tu...@ws.apache.org>
> Sent: Wednesday, June 06, 2007 12:31 PM
> Subject: Re: CompositeBuilderImpl.createSelfReferences creates a $self$
> reference using the service binding
>
>
>> I'm actually bumping up against one of the problems that ant has
>> described - the creation of $self$ reference URIs.
>>
>> I don't believe a binding implementation should have to expect to deal
>> with odd URI's that were generated by the runtime and I'm curious how
>> bindings are supposed to know what to do with each of forms that are
>> invented.
>>
>> In the case of the binding implementation I'm working with, the
>> reference binding uses the uri to determine the target service. When
>> the URI is changed it is no longer valid as no service exists with at
>> the modified URI.
>>
>> Any ideas on how this could be implemented without forcing the
>> bindings to understand $self$ references?
>>
>> Thanks.
>>
>> ant elder wrote:
>>
>>> I think its actually a bug in the jsonrpc binding that its using the
>>> component self reference, but that aside, this still seems odd to me.
>>> Just
>>> because a particular binding is on a service how can it be sure that
>>> that
>>> same binding will work as a reference? Some binding's don't support
>>> references, some have different attributes for services or
>>> references, on
>>> some binding's the URI may include the reference name so this would
>>> end up
>>> including $self$ in the URI.
>>>
>>> ...ant
>>>
>>> On 5/18/07, Raymond Feng <en...@gmail.com> wrote:
>>>
>>>>
>>>> Hi,
>>>>
>>>> The self references are created to support the
>>>> ComponentContext.createSelfReference() in a consistent way as regular
>>>> references.
>>>>
>>>> In your case, if the binding.jsonrpc is declared under the
>>>> component, then
>>>> the component can only be assessed over jsonrpc binding (not even SCA
>>>> binding). And the component will be exposed as a json-rpc service. So
>>>> invoking the json-rpc reference handler is the correct behavior from
>>>> the
>>>> client side.
>>>>
>>>> Thanks,
>>>> Raymond
>>>
>>>
>>
>> --
>> Matthew Sykes
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: tuscany-dev-unsubscribe@ws.apache.org
>> For additional commands, e-mail: tuscany-dev-help@ws.apache.org
>>
>
>
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>
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Re: CompositeBuilderImpl.createSelfReferences creates a $self$ reference using the service binding
Posted by Raymond Feng <en...@gmail.com>.
Hi,
Let's look at a use case:
Assuming we have a deployable composite as follows.
<composite ...>
<component name="MyComponent">
<service name="MyService>
<binding.ws .../>
</service>
</component>
</composite>
When this composite is deployed to the SCA domain, then "MyService" should
be available over the Web Service binding. Let's assume that the deployed
URI is http://localhost:8080/MyComponent/MyService.
Now it becomes interesting: Is "MyService" available for
SCADomain.getService(MyService.class, "MyComponent/MyService")? If so, which
binding should be used?
If the answer is yes, I think by the SCA spec, only Web Service binding is
available to access MyService. Then the service proxy returned from
SCADomain.getService(...) will be a self reference with a Web Service
binding and the binding URI should be the SAME as the calculated service
binding URI, i.e., http://localhost:8080/MyComponent/MyService. (I think
the binding URI for the self reference is not correctly filled today and
that's why the $self$ comes into the binding providers' faces).
The other option is that if the service doesn't have a SCA binding,
SCADomain.getService(...) will throw ServiceUnavailableException.
Thanks,
Raymond
----- Original Message -----
From: "Matthew Sykes" <sy...@gmail.com>
To: <tu...@ws.apache.org>
Sent: Wednesday, June 06, 2007 12:31 PM
Subject: Re: CompositeBuilderImpl.createSelfReferences creates a $self$
reference using the service binding
> I'm actually bumping up against one of the problems that ant has
> described - the creation of $self$ reference URIs.
>
> I don't believe a binding implementation should have to expect to deal
> with odd URI's that were generated by the runtime and I'm curious how
> bindings are supposed to know what to do with each of forms that are
> invented.
>
> In the case of the binding implementation I'm working with, the reference
> binding uses the uri to determine the target service. When the URI is
> changed it is no longer valid as no service exists with at the modified
> URI.
>
> Any ideas on how this could be implemented without forcing the bindings to
> understand $self$ references?
>
> Thanks.
>
> ant elder wrote:
>> I think its actually a bug in the jsonrpc binding that its using the
>> component self reference, but that aside, this still seems odd to me.
>> Just
>> because a particular binding is on a service how can it be sure that that
>> same binding will work as a reference? Some binding's don't support
>> references, some have different attributes for services or references, on
>> some binding's the URI may include the reference name so this would end
>> up
>> including $self$ in the URI.
>>
>> ...ant
>>
>> On 5/18/07, Raymond Feng <en...@gmail.com> wrote:
>>>
>>> Hi,
>>>
>>> The self references are created to support the
>>> ComponentContext.createSelfReference() in a consistent way as regular
>>> references.
>>>
>>> In your case, if the binding.jsonrpc is declared under the component,
>>> then
>>> the component can only be assessed over jsonrpc binding (not even SCA
>>> binding). And the component will be exposed as a json-rpc service. So
>>> invoking the json-rpc reference handler is the correct behavior from the
>>> client side.
>>>
>>> Thanks,
>>> Raymond
>>
>
> --
> Matthew Sykes
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tuscany-dev-unsubscribe@ws.apache.org
> For additional commands, e-mail: tuscany-dev-help@ws.apache.org
>
---------------------------------------------------------------------
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Re: CompositeBuilderImpl.createSelfReferences creates a $self$ reference
using the service binding
Posted by Matthew Sykes <sy...@gmail.com>.
Sebastien,
I should say that I'm working on a default binding that replaces the
Tuscany implementation. The URI isn't changed but new references are
created with target URIs that are unknown to the binding implementation
on the service side.
CompositeBuilderImpl.createSelfReferences creates new references for
each service and sets the name to $self$.<servicename>. Later
wireComposite iterates over each of the references and finds the new
$self$ references and associates it with the default binding.
On paths where SCARuntime.getService is called, createSelfReference
eventually follows and the Reference passed back to the caller is one
that holds generated uri. As the reference's target URI doesn't point
to a service exposed at that URI, invocations through the reference are
failing.
I can see how I might work around this in the binding but I'm not sure
that I should have to. ;)
Thanks.
Jean-Sebastien Delfino wrote:
> Matthew Sykes wrote:
>> I'm actually bumping up against one of the problems that ant has
>> described - the creation of $self$ reference URIs.
>>
>> I don't believe a binding implementation should have to expect to deal
>> with odd URI's that were generated by the runtime and I'm curious how
>> bindings are supposed to know what to do with each of forms that are
>> invented.
>>
>> In the case of the binding implementation I'm working with, the
>> reference binding uses the uri to determine the target service. When
>> the URI is changed it is no longer valid as no service exists with at
>> the modified URI.
>
> I'm trying to understand the problem that you're running into, and I'm
> not sure why the URI would change. A new "self" reference created in
> CompositeBuilderImpl.createSelfReferences actually points to the
> original bindings of the service that the reference is created for. So
> as far as I can tell, the URI used by the reference is the same (meaning
> exactly the same object) as the URI declared on the service's binding.
>
> So if the URI changes there's a bigger problem, as it's probably going
> to break the service itself... Are you actually seeing the URI change?
> do you have a test case that I could use to debug that?
>
> Thanks.
>
>
> --
>
> Jean-Sebastien
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tuscany-dev-unsubscribe@ws.apache.org
> For additional commands, e-mail: tuscany-dev-help@ws.apache.org
>
>
--
Matthew Sykes
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Re: CompositeBuilderImpl.createSelfReferences creates a $self$ reference
using the service binding
Posted by Jean-Sebastien Delfino <js...@apache.org>.
Matthew Sykes wrote:
> I'm actually bumping up against one of the problems that ant has
> described - the creation of $self$ reference URIs.
>
> I don't believe a binding implementation should have to expect to deal
> with odd URI's that were generated by the runtime and I'm curious how
> bindings are supposed to know what to do with each of forms that are
> invented.
>
> In the case of the binding implementation I'm working with, the
> reference binding uses the uri to determine the target service. When
> the URI is changed it is no longer valid as no service exists with at
> the modified URI.
I'm trying to understand the problem that you're running into, and I'm
not sure why the URI would change. A new "self" reference created in
CompositeBuilderImpl.createSelfReferences actually points to the
original bindings of the service that the reference is created for. So
as far as I can tell, the URI used by the reference is the same (meaning
exactly the same object) as the URI declared on the service's binding.
So if the URI changes there's a bigger problem, as it's probably going
to break the service itself... Are you actually seeing the URI change?
do you have a test case that I could use to debug that?
Thanks.
--
Jean-Sebastien
---------------------------------------------------------------------
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Re: CompositeBuilderImpl.createSelfReferences creates a $self$ reference
using the service binding
Posted by Matthew Sykes <sy...@gmail.com>.
I'm actually bumping up against one of the problems that ant has
described - the creation of $self$ reference URIs.
I don't believe a binding implementation should have to expect to deal
with odd URI's that were generated by the runtime and I'm curious how
bindings are supposed to know what to do with each of forms that are
invented.
In the case of the binding implementation I'm working with, the
reference binding uses the uri to determine the target service. When
the URI is changed it is no longer valid as no service exists with at
the modified URI.
Any ideas on how this could be implemented without forcing the bindings
to understand $self$ references?
Thanks.
ant elder wrote:
> I think its actually a bug in the jsonrpc binding that its using the
> component self reference, but that aside, this still seems odd to me. Just
> because a particular binding is on a service how can it be sure that that
> same binding will work as a reference? Some binding's don't support
> references, some have different attributes for services or references, on
> some binding's the URI may include the reference name so this would end up
> including $self$ in the URI.
>
> ...ant
>
> On 5/18/07, Raymond Feng <en...@gmail.com> wrote:
>>
>> Hi,
>>
>> The self references are created to support the
>> ComponentContext.createSelfReference() in a consistent way as regular
>> references.
>>
>> In your case, if the binding.jsonrpc is declared under the component,
>> then
>> the component can only be assessed over jsonrpc binding (not even SCA
>> binding). And the component will be exposed as a json-rpc service. So
>> invoking the json-rpc reference handler is the correct behavior from the
>> client side.
>>
>> Thanks,
>> Raymond
>
--
Matthew Sykes
---------------------------------------------------------------------
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Re: CompositeBuilderImpl.createSelfReferences creates a $self$ reference using the service binding
Posted by ant elder <an...@gmail.com>.
I think its actually a bug in the jsonrpc binding that its using the
component self reference, but that aside, this still seems odd to me. Just
because a particular binding is on a service how can it be sure that that
same binding will work as a reference? Some binding's don't support
references, some have different attributes for services or references, on
some binding's the URI may include the reference name so this would end up
including $self$ in the URI.
...ant
On 5/18/07, Raymond Feng <en...@gmail.com> wrote:
>
> Hi,
>
> The self references are created to support the
> ComponentContext.createSelfReference() in a consistent way as regular
> references.
>
> In your case, if the binding.jsonrpc is declared under the component, then
> the component can only be assessed over jsonrpc binding (not even SCA
> binding). And the component will be exposed as a json-rpc service. So
> invoking the json-rpc reference handler is the correct behavior from the
> client side.
>
> Thanks,
> Raymond
>
> ----- Original Message -----
> From: "ant elder" <an...@gmail.com>
> To: <tu...@ws.apache.org>
> Sent: Friday, May 18, 2007 9:32 AM
> Subject: CompositeBuilderImpl.createSelfReferences creates a $self$
> reference using the service binding
>
>
> > Debugging TUSCANY-1292 it looks like one part of the problem is that
> > CompositeBuilderImpl.createSelfReferences creates a new self reference
> for
> > each service on a component and adds every binding from that service
> into
> > the new reference. That results is a JSON-RPC reference provider get
> used
> > which seems strange to me but I don't completely understand what the
> > createSelfReferences is trying to do. Does anyone understand this more
> and
> > know if this is the correct behaviour or not?
> >
> > ...ant
> >
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tuscany-dev-unsubscribe@ws.apache.org
> For additional commands, e-mail: tuscany-dev-help@ws.apache.org
>
>
Re: CompositeBuilderImpl.createSelfReferences creates a $self$ reference using the service binding
Posted by Raymond Feng <en...@gmail.com>.
Hi,
The self references are created to support the
ComponentContext.createSelfReference() in a consistent way as regular
references.
In your case, if the binding.jsonrpc is declared under the component, then
the component can only be assessed over jsonrpc binding (not even SCA
binding). And the component will be exposed as a json-rpc service. So
invoking the json-rpc reference handler is the correct behavior from the
client side.
Thanks,
Raymond
----- Original Message -----
From: "ant elder" <an...@gmail.com>
To: <tu...@ws.apache.org>
Sent: Friday, May 18, 2007 9:32 AM
Subject: CompositeBuilderImpl.createSelfReferences creates a $self$
reference using the service binding
> Debugging TUSCANY-1292 it looks like one part of the problem is that
> CompositeBuilderImpl.createSelfReferences creates a new self reference for
> each service on a component and adds every binding from that service into
> the new reference. That results is a JSON-RPC reference provider get used
> which seems strange to me but I don't completely understand what the
> createSelfReferences is trying to do. Does anyone understand this more and
> know if this is the correct behaviour or not?
>
> ...ant
>
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