A PPARC funded project Common Execution Architecture Paul Harrison IVOA Interoperability Meeting...
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Transcript of A PPARC funded project Common Execution Architecture Paul Harrison IVOA Interoperability Meeting...
A PPARC funded project
Common Execution Architecture
Paul HarrisonIVOA Interoperability MeetingCambridge MA23-28 May 2004
Apr 21, 2023 IVOA Interoperability Meeting: Common Execution Architecture 2
IntroductionCommon Execution Architecture (CEA)
An attempt to model how an application is run in the Virtual Observatory An application is any process that consumes
or produces data
Designed primarily to work in web services environment A set of schema and WSDL definitions
Apr 21, 2023 IVOA Interoperability Meeting: Common Execution Architecture 3
MotivationTo create a model of an application VO infrastructure only has to deal with a single
application model Application writers know how to interface VO
Provide higher level description than WSDL Restrict to manageable subset Provide specific semantics for astronomical
Quantities Provide extra information - e.g. Defaults Data flow does not necessarily follow call tree
Asynchronous Operation
Apr 21, 2023 IVOA Interoperability Meeting: Common Execution Architecture 4
HistoryThe desire to be able to create a workflow Engine in AstroGridDerived from the Iteration 4 Command Line Application Controller experiences.
It is a work-in-progress Will definitely evolve in next few months
Apr 21, 2023 IVOA Interoperability Meeting: Common Execution Architecture 5
Application Model
Apr 21, 2023 IVOA Interoperability Meeting: Common Execution Architecture 6
ComponentsApplication Command line, web service
Common Execution Controller Controls the application, interacts with the
other components
Invoking process Workflow, web service, script
Monitoring Service Receives the status messages
Storage Service
Apr 21, 2023 IVOA Interoperability Meeting: Common Execution Architecture 7
Component InteractionsUML Sequence Diagram The monitoring service could be same as
invoking service The only guaranteed status message is the
final one The results of running the application are not
returned directly to the invoking process. The destination is implicit in the specification of the output parameters
Apr 21, 2023 IVOA Interoperability Meeting: Common Execution Architecture 8
How to use itAstroGrid Iteration 5 released at end of month Look at test environment!!
AstroGrid exposes all these components as web services Workflow is an xml document
Not limited to using AstroGrid portal Script Extend existing VO Tools (e.g. Aladin)
Apr 21, 2023 IVOA Interoperability Meeting: Common Execution Architecture 9
Deployment ScenarioUML Diagram Command line applications that are wrapped
by specialized CommonExecutionControllers that make a compute farm
Web services proxy component that can act as an adapter between a generic web service and the CommonExecutionConnector interface
Web services proxy can be localised with a web service so that the results returned can be stored locally thus minimising network traffic
Apr 21, 2023 IVOA Interoperability Meeting: Common Execution Architecture 10
How to integrate your Applications
Command Line Execution Controller already exists CEA web service wrapper for UNIX
command lines Interacts with workflow, MySpace Simply a case of configuring the application
in the registry If you want to wrap functionality easy to do by
extending the CommandLineApplication class.
Implement the CommonExecutionConnector Interface directly.
Apr 21, 2023 IVOA Interoperability Meeting: Common Execution Architecture 11
SummaryCEA creates an environment to send messages to and from applications.
Implemented in AstroGrid Workflow with a CEC for Command Line applications Configuration only web service. Iteration 6 will produce general CEC proxy for
any web service.
See maven page http://www.astrogrid.org/maven/docs/
snapshot/applications/