On Thu, Mar 4, 2010 at 11:00 PM, ant elder <[email protected]> wrote:
> On Fri, Mar 5, 2010 at 11:40 AM, Raymond Feng <[email protected]> wrote:
>> Hi,
>>
>> When an SCA service is published to a binding protocol, it's assigned with
>> an address (represented as a URI) so that the service can be accessed from
>> the client side using that address. For example, a web service binding can
>> be made available at http://myhost:9080/myService.
>>
>> We use the endpoint registry to propagate endpoint descriptions from the
>> node that hosts the endpoint to other nodes in the SCA domain. The
>> protocol-specific physical endpoint address needs to be carried with the
>> endpoint description via the registry. The other tricky thing is to make
>> sure the endpoint address is accessible from a different machine. This leads
>> to a few cases:
>>
>> 1) The service binding URI is http://localhost:9080/myService. Should the
>> localhost be left as-is or replaced with the host ip or name?
>> 2) Should we use IP addess or host name?
>> 3) What do we do if the host machine is multiple homed?
>>
>> For some of the bindings, we have ServletHost or RMIHost to represent the
>> protocol stacks. The "regsiterService" can return a URI to represent a
>> physical endpoint address that can be used outside of the hosting machine.
>>
>> Now we allow the binding.sca to be mapped to any of the bindings. It
>> requires the mapped binding to propagate the physical URI to the client side
>> too.
>>
>> Two questions to be answered:
>>
>> 1) How does a binding generate the physical endpoint address based on the
>> binding URI and other information?
>> 2) The binding provider should be responsible for setting the binding with
>> the "deployed" URI (do we need to have a separate property in the Binding
>> java model?) into the endpoint so that it can be propagated into the
>> endpoint registry?
>>
>>
>
> Yep its a problem alright, i've been thing about too.
>
> The only way I can see it working well is if Tuscany has a proper
> fixed base url per protocol and have _everything_ that uses that
> protocol use that base url, that means anything that listens for
> things remote requests eg the endpoint registry. Ideally as much as
> possible we'd want to try to choose the value programatically so users
> don't need to manually configure it, but that can get hard especially
> with multiple network interfaces, virtual hosts, and public/private
> host names. Pragmatically we're mainly interested in the host name/ip
> addresses, so likely often times we might just need to manually
> specify that/those when starting a Tuscany runtime.
>
> ...ant
>
In the binding.sca case:
- There is no binding URI on the service side so we have to rely on
the default binding URI generated schema for the binding that is
mapped
- The URI on the reference is an SCA target name and we rely on the
configuration of the service endpoint to configure the mapping on the
reference.
- Ant's point is a good one and I think we have taken this approach
with the node configuration file where base URIs can be set for each
scheme.
I wondering though whether the default URI generated for bindings used
for remote binding sca support need to be different from default URIs
generation for bindings added manually. For example,
<component ...>
<service ...>
<binding.sca/>
<binding.ws/>
</service>
</component>
Assuming that ws maps to the sca binding, will that try to register
the same service endpoint twice?
As to the questions...
1/ I think based on the algorithm embodied in BindingURIBuilderImpl,
which pretty much takes the based URI for a scheme and adds either the
structural URI or and relative stuff from the binding URI.
2/ Can you say a bit more about why another field might be required?
Is this to separate the deployed URI from what was originally entered
by the user into the binding uri field?
Simon
