Universal Worker Service (UWS) RFC (Version 1.0)

This document is a "Request for Comment" (RFC) for the Proposed Recommendation "Universal Worker Service V1.0". The specification can be found at http://www.ivoa.net/Documents/UWS/20090909/PR-UWS-1.0-20090909.html

Review Period: 05 Oct 2009 - 05 Nov 2009.

In order to add a comment to the document, please edit this page and add your comment to the list below in the format used for the example (include your WikiName so that authors can contact you for further information). When the author(s) of the document have considered the comment, they will provide a response after the comment.

Additional discussion about any of the comments or responses can be conducted on the GWS WG mailing list, grid@ivoa.net. However, please be sure to enter your initial comments here for full consideration in any future revisions of this document

Comments from the community

• Sample comment by WikiName
  • Response (by WikiName)

• Reusing Roy's (unanswered) comment on the TAP's RFC: "Isn't there a requirement for implementations or prototypes before a standard can go to RFC? Please can somebody post the service URLs of these, so that I can try out this new standard for real?" I understand (and apologise for it) that it is very cheap on me (not developing any of that) saying so, but it is important to follow the established process. Thanks, Alberto Micol
  • PatrickDowler 2009-10-06 We have a sample UWS service for testing our base UWS software and as an example: http://www.cadc.hia.nrc.gc.ca/cadcSampleUWS/
  • PaulHarrison In addition the AstroGrid CEA servers have been prototyping UWS for several years now - see eg report from the Trieste Interop and http://astrogrid.jb.man.ac.uk:8080/cea-commandline/ for a working service.

Comments from TCG Review during the normal RFC period

Applications (Tom McGlynn, Mark Taylor)

This document is well thought out and well written. -- MarkTaylor

Data Access Layer (Keith Noddle, Jesus Salgado)

Data Model (Mireille Louys, AnitaRichards)

Grid&Web Sevices (Matthew Graham, Paul Harrison)

Registry (Ray Plante, Aurelien Stebe)

Semantics (Sebastien Derriere, Norman Gray)

VOEvent (Rob Seaman, Alasdair Allan)

VO Query Language (Pedro Osuna, Yuji Shirasaki)

VOTable (Francois Ochsenbein)

Standard and Processes (Francoise Genova)

Astro RG (Masatoshi Ohishi)

Data Curation & Preservation (Bob Hanisch)

The preamble lacks the usual language about terms “should”, “must”, “may”, etc., and it is not clear in the main document just how the “should”s, etc., are to be interpreted.

Sections 4 and 5 are labeled as “informative”, suggesting that the rest of the document is “normative”. However, the Introduction (which gives a nice explanation of the general background) would appear to be “informative” as well.

In Section 1.1, first item in bulleted list, “...times out at” should be “...times out and”

I suggest removed the Section heading 1.2 and simply merging the text into 1.1, with something like this transition sentence: “The following examples illustrate situations in the VO in which synchronous, stateless services are inadequate.”

In item 3 following the above, VOSpace needs a reference.

In Section 1.3, 2nd paragraph, “Most of special...” should be “Most of the special...”

In Section 1.4, change “E.g.” to “For example” (just seems bad form to start a sentence with an abbreviation). And later in that paragraph, CEA appears for the first time and is not referenced. It is referenced two paragraphs later, but should be referenced on the first occurrence.

Section 2.1.2, “Each job aggregates” might be clearer as “Each job contains”, and add a colon.

Section 2.1.3, semicolon at end of introductory clause should be a colon.

Section 2.1.5, ditto.

Section 2.1.6, how is a service to supply a “don’t know” answer? How is this to be encoded?

Section 2.1.7 mentions an optional errorSummary element, but this is not shown in the UML diagram in Section 2.1.

Section 2.1.11, the first sentence is not very clear. Who/what is reading the parameter list?

Section 2.2.1, the UML diagram uses JobList as the outermost object, but now it seems to be called “jobs”.

Section 2.2.2.2, the first sentence does not scan.

Section 4.2, last word “emit” might be better as “return”.

Section 4.3, check for missing periods (there are at least two).

Section 5, first sentence should end with a period, not a semicolon.

Appendix B has a number of casual remarks suggesting that the proposal is not very stable.

Primary concern: The first paragraphs of Section 4 note that the document does not define “two essential parts of the service contract.” The examples “are neither formal nor complete. The intention is to show a range of ways that the pattern can be applied without burdening the reader with the level of detail needed for a standard implementation.”

Well, when I read this I wonder just what is being defined at all, and how this document advances the cause of the IVOA. If it does not provide a full definition of how to implement and manage asynchronous jobs, what are software designers and implementers supposed to do with this? What exactly are we recommending, in the sense of promoting this to a REC? How can we judge having interoperable implementations when there is no detailed specification? I read the comment above from Alberto Micol, and do not find the responses from Pat Dowler and Paul Harrison very satisfying in this regard.

rjh, 19 Oct 2009

Theory (Herve Wozniak, Claudio Gheller)

TCG (ChristopheArviset, Severin Gaudet)