Universal Worker Service Guy Rixon to GWSWG at

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

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

Why UWS? n n More code reuse, because standard WSDL contract 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 connecting to grids, because semantics are inherently grid-like IVOA interop meeting, Kyoto, May 2005 3

UWS is abstracted from CEA v 1 1. 2. 3. 4. 5. 6. Job-description language (JDL) WSDL contract Standard semantics for job-based service IVOA resource schema for job-based services IVOA resource schema for applications 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 v 2, maybe. It needs a JDL but need not use the one from CEA v 1. IVOA interop meeting, Kyoto, May 2005 4

Why change CEA v 1? n n n Easier to implement: refactored to use WS -RF More features in WSDL contract, e. g. runtime estimation, checkpointing/restarting More flexible: spec’d to work with JDLs other than the CEA one. IVOA interop meeting, Kyoto, May 2005 5

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

UWS issues: shall we proceed? n n Do we want any standard for async. Activities? Would we rather bless CEA v 1 without mucking it around? 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? IVOA interop meeting, Kyoto, May 2005 7

UWS issues: operation set n n n Is the command set in the v 0. 1 spec. sufficient? Is it sane? Is it too much? (Should we make more of it optional? ) IVOA interop meeting, Kyoto, May 2005 8

UWS issues: pluggable JDL n n n 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? If the latter, should we refactor into a common port-type plus one port-type per JDL. IVOA interop meeting, Kyoto, May 2005 9

UWS issues: registration n n 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”? n n n Do we have a resource type for UWS? Is this different from cea. Application. Type? How do we say which JDL a UWS is using? n n Do we have one resource type per JDL? Q. v. one-WSDL-contract-per-JDL idea. IVOA interop meeting, Kyoto, May 2005 10

UWS issues: data grid n n CEA depends on Astro. Grid My. Space. Should UWS depend on the data grid? On the VOSpace layer? n On the VOStore layer only? n n n NB: CEA v 2 must handle the data grid. Is data-grid handling pluggable along with the JDL? IVOA interop meeting, Kyoto, May 2005 11