1. 1 Universal Worker Service Guy Rixon to GWS-WG at IVOA interoperability meeting, Kyoto, May 2005

2. IVOA interop meeting, Kyoto, May 2005Universal Worker Service, slide 2 Definition UWS defines a WSDL contract and service semantics for job-based services. Job- based means that: UWS defines a WSDL contract and service semantics for job-based services. Job- based means that: Service executes work asynchronously, (in batch) Service executes work asynchronously, (in batch) Service takes instructions in a Job-Description Language (JDL) document, not like an RPC. Service takes instructions in a Job-Description Language (JDL) document, not like an RPC. Service is stateful and provides a way to interact with individual jobs. Service is stateful and provides a way to interact with individual jobs.

3. IVOA interop meeting, Kyoto, May 2005Universal Worker Service, slide 3 Why UWS? More code reuse, because standard WSDL contract More code reuse, because standard WSDL contract Good for workflows, because job-step defined by a document in a job- description language Good for workflows, because job-step defined by a document in a job- description language Good for long-running activities, because job-steps run asynchronously Good for long-running activities, because job-steps run asynchronously Good for connecting to grids, because semantics are inherently grid-like Good for connecting to grids, because semantics are inherently grid-like

4. IVOA interop meeting, Kyoto, May 2005Universal Worker Service, slide 4 UWS is abstracted from CEA v1 1. Job-description language (JDL) 2. WSDL contract 3. Standard semantics for job-based service 4. IVOA resource schema for job-based services 5. IVOA resource schema for applications 6. Application-description schemata (used in JDL, resource schemata and local configuration) UWS is the WSDL, the semantics and maybe the service-resource schema. Part of CEA v2, maybe. It needs a JDL but need not use the one from CEA v1.

5. IVOA interop meeting, Kyoto, May 2005Universal Worker Service, slide 5 Why change CEA v1? Easier to implement: refactored to use WS-RF Easier to implement: refactored to use WS-RF More features in WSDL contract, e.g. run- time estimation, checkpointing/restarting More features in WSDL contract, e.g. run- time estimation, checkpointing/restarting More flexible: specd to work with JDLs other than the CEA one. More flexible: specd to work with JDLs other than the CEA one.

6. IVOA interop meeting, Kyoto, May 2005Universal Worker Service, slide 6 Why not use a grid standard? Good question! Good question! There arent any, yet: There arent any, yet: OGSA neither finished nor implemented. OGSA neither finished nor implemented. Others are de facto, not de jure and not multi-vendor Others are de facto, not de jure and not multi-vendor Grid stuff doesnt cover all of CEA: Grid stuff doesnt cover all of CEA: Application registration. Application registration. Application description for UI. Application description for UI. Application libraries with mirror servers. Application libraries with mirror servers. …and wed like to go on using CEA, please. …and wed like to go on using CEA, please.

7. IVOA interop meeting, Kyoto, May 2005Universal Worker Service, slide 7 UWS issues: shall we proceed? Do we want any standard for async. Activities? Do we want any standard for async. Activities? Would we rather bless CEA v1 without mucking it around? Would we rather bless CEA v1 without mucking it around? Do we want some other way of doing this stuff? Do we want some other way of doing this stuff? If we go ahead with UWS, who wants to work on the prototypes and spec? If we go ahead with UWS, who wants to work on the prototypes and spec?

8. IVOA interop meeting, Kyoto, May 2005Universal Worker Service, slide 8 UWS issues: operation set Is the command set in the v0.1 spec. sufficient? Is the command set in the v0.1 spec. sufficient? Is it sane? Is it sane? Is it too much? (Should we make more of it optional?) Is it too much? (Should we make more of it optional?)

9. IVOA interop meeting, Kyoto, May 2005Universal Worker Service, slide 9 UWS issues: pluggable JDL Is it sensible to have a WSDL that allows any JDL? Is it sensible to have a WSDL that allows any JDL? Is it better to have one WSDL per JDL, but to keep to a common pattern? Is it better to have one WSDL per JDL, but to keep to a common pattern? If the latter, should we refactor into a common port-type plus one port-type per JDL. If the latter, should we refactor into a common port-type plus one port-type per JDL.

10. IVOA interop meeting, Kyoto, May 2005Universal Worker Service, slide 10 UWS issues: registration Is the CEA application/service split OK, or do we need a different arrangement? (Q.v. forthcoming data-model team in Registry-WG) Is the CEA application/service split OK, or do we need a different arrangement? (Q.v. forthcoming data-model team in Registry-WG) How do we say this service is a UWS? How do we say this service is a UWS? Do we have a resource type for UWS? Do we have a resource type for UWS? Is this different from ceaApplicationType? Is this different from ceaApplicationType? How do we say which JDL a UWS is using? How do we say which JDL a UWS is using? Do we have one resource type per JDL? Do we have one resource type per JDL? Q.v. one-WSDL-contract-per-JDL idea. Q.v. one-WSDL-contract-per-JDL idea.

11. IVOA interop meeting, Kyoto, May 2005Universal Worker Service, slide 11 UWS issues: data grid CEA depends on AstroGrid MySpace. CEA depends on AstroGrid MySpace. Should UWS depend on the data grid? Should UWS depend on the data grid? On the VOSpace layer? On the VOSpace layer? On the VOStore layer only? On the VOStore layer only? NB: CEA v2 must handle the data grid. NB: CEA v2 must handle the data grid. Is data-grid handling pluggable along with the JDL? Is data-grid handling pluggable along with the JDL?