Hi Sebastien,
Nice write-up - thanks a lot for doing this.
I'm generally o.k. with these with a few caveats:
1. We'll need to scope because I think there is a lot more here than
we can accomplish
2. As a pre-req to do this, I think we need to have the following in
place. My view is that while we will be continually playing with the
core architecture moving forward, we need to make some changes now to
avoid some immediate problems. Things I would like to do in
conjunction with this work:
- Transition to new context architecture and get rid of
TuscanyModuleComponentContextImpl. Right now, we can't unit test a
module context, separate out SDO or effectively implement management
hooks and overrides for entry points/ external services. We also
can't modularize very well any capabilities we may want to add to a
runtime such as binding extensions, component extensions, etc.
TuscanyModuleComponentContextImpl also contains a dependency on
projects it should not (e.g. it depends on the Java builder but
"cheats" by referring to the impl class with a String and performing
newInstance()).
- Fix how proxying works. Right now the target and source
proxies are not distinguished enough. This will effect what we can
do with policies and overrides, particularly at the subsystem level.
Another way of phrasing the above is to say in addition to the "end-
user oriented" goals you outlined, we need to have these
architectural goals. I believe once we do this, the runtime will be
dramatically simplified, we will be able to get rid of a lot of dead
code, and it will be easier to attract people to work on the runtime
and add extensions (e.g. new component types, transport bindings,
policies, data binding, etc.).
I've already written a replacement for
TuscanyModuleComponentContextImpl and checked it in with unit tests.
I'm also working on the proxying. I'll check those in when I make
progress that does not break the build. Unless there are any
objections, I'm volunteering to do the work to meet that goal.
Jim
On Feb 1, 2006, at 12:51 PM, Jean-Sebastien Delfino wrote:
Hi,
I started to put together a list of items that I think we should
support in our first SCA/Java Milestone. The idea is to establish
reasonable goals in terms of function and timeframe. I also think
that this will help people find areas where they can contribute,
since this is pretty broad.
Core Module assembly model
- align implementation with a subset of SCA 0.9 (the implementation
diverges from SCA 0.9 in some areas today)
- support for module and fragment SCDL
- support for componentType
- no multiplicity
- simple properties only, no complex properties
- support for both Java and WSDL interfaces
Subsystem assembly model
- support for subsystem SCDL
- ModuleComponents only no externalService and entryPoint at the
subsystem level
- Support for wiring/specifying endpoints on externalServices
- Support for overriding properties of moduleComponents
- On Tomcat, subsystem maps to a Tomcat instance, moduleComponent
maps to a Web app
- In J2SE, you can run a single moduleComponent
Client and implementation model
- align implementation with a subset of SCA 0.9
- support for SDO2 as well as regular Java objects - basic scope
management (request, session, module)
- no metadata API
- no request context
- no session id
- no service references
- no conversational, no callbacks
Development Tools
- WSDL2Java and Java2WSDL generators
- XSD2SDO and Java2SDO generators
- both in the form of API and maven plugins
Bindings
- Web Service binding using AXIS 2 (SOAP/HTTP, doc literal only,
support for streaming)
- Pluggable data-binding (start with regular Java objects and SDO)
- I think that we can live with just a WS binding for now and look
at the default SCA binding later (maybe it'll just be a variation
of the WS binding with some defaults anyway).
Extensibility
- Support contribution of a new binding (I'm thinking about a
sample HTTP binding to illustrate that)
- Support contribution of a new component type (Ant's sample
Javascript component type)
Admin
- just doc or basic tools (maven plugin?) to install/uninstall a
subsystem and module component
- just doc or basic tools to start/stop a subsystem and module
component
- wiring, configuration of module component properties require
editing SCDL file and bouncing the subsystem
- Simple monitoring/logging
Target environments
- JDK 5.0
- Tomcat
- J2SE
Samples
I think we need samples for most of the items in this list to
illustrate how various user roles will use Tuscany (app. developer,
assembler, deployer-admin, system-developer who wants to extend or
integrate with Tuscany) and help drive all this work from concrete
scenarios.
Any thoughts and ideas are welcome.
--
Jean-Sebastien
