Hi Pavel,
On Thu, 31 Mar 2011, [email protected] wrote:
Hi,
I would like to kindly ask you for your opinion how to solve the following
situation.
I have a simple globus toolkit project using ws-core-4.0.8 which exposes data
from sensor to a client. Project is written in IDE Eclipse according to the
?Using Eclipse to develop grid services? (presented by developerWorks) and
uses ?globus build service? script to build gar file which is afterwards
deployed to the Apache Tomcat 5.3.31. I would like to improve the project to
use data from databases (I have already work with ogsadai-4.0-axis-1.4) and
inform client about data changes. My idea is to use ogsadai-4.1-gt-4.2.0 in
order to provide data from databases which will be exposed as grid resources
to the client which will be notified about changes of resources by means of
GT4 WS-notification. I would like to ask you for advice what steps I should
perform to be able to create such functionality. Should I write a new
Activity or it is possible to use ws-core functionality within ogsadai client
toolkit code? And how do I build the globus toolkit code (wsdl, service
implementation,deployment files) and how do I deploy it along with
ogsadai-4.1-gt-4.2.0 (?globus build service? script doesn't work with
ws-core-4.2.0 properly)? Can I ask for a hint or for some suggestions how you
would do it?
Thank you.
Pavel
These are some comments. They assume you know how to write web service
clients and services using Globus Toolkit and the Axis WSDL2Java tool.
OGSA-DAI services support WS-ResourceProperties and WS-ResourceLifetime
portTypes. The client toolkit exposes operations based on these portTypes.
This, along with security, is the only WS-Core functionality supported by
the client toolkit at present.
If you look at an OGSA-DAI source release you'll see it just runs a build
script that invokes various operations in directories that each represent
OGSA-DAI components or modules. One of these is
presentation/globus/4.2/stubs
which assembles the OGSA-DAI GT WSDL and invokes Globus Toolkit WSDL2Java
functionality to auto-generate client and server side stub classes.
OGSA-DAI is layered. The core server-side functionality has no knowledge
of web services or GT at all. There is then a layer that wraps OGSA-DAI
components (especially resources and properties) into GT-compliant
wrappers. This then uses the auto-generated classes above. Similar
comments apply to the client toolkit.
Neither OGSA-DAI services nor the client toolkit support WS-Notification
at present.
You'd have to alter the OGSA-DAI WSDL service descriptions to
import/include the relevant WS-Notification operations.
You'd then have to regenerate auto-generated server-side service interface
classes. At it's simplest this would just involve trying to rebuild a
binary distribution from a source distribution to which you'd made the
above WSDL changes.
And, you'd have to update the server-config.wsdd deployment descriptor to
specify the additional portTypes.
Then you'd have to either modify the client toolkit to support
WS-Notification operations or just build requests using auto-generated
client-side stubs directly.
All of this is time consuming but should be straightforward. The biggest
challenge you'd face is a Java component/class that can listen for and
detect changes in the databases. Once this is done then you'd need some
way of invoking WS-Notification functionality.
Cheers,
mike
CCd to ogsa-dai-users as same question was posted there.
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Dr. Michael (Mike) Jackson E-mail: [email protected]
EPCC http://www.epcc.ed.ac.uk
Software Sustainability Institute http://www.software.ac.uk
OGSA-DAI Open Source Project http://tinyurl.com/ogsa-dai
OGSA-DAI http://www.ogsadai.org.uk
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.
