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RE: WS BPEL URIs for RDDLs, WSDLs, Schemas, etc

From
Mary McRae <>
Date
2006-08-26T00:13:34+00:00
ID
001101c6c8a4$7fd40170$640fa8c0@espresso
Thread
RE: WS BPEL URIs for RDDLs, WSDLs, Schemas, etc
Hi Diane,

 

  The only outstanding issue is the use of the 
filename "index.html". This name is reserved by OASIS. Instead, the RDDL file 
should be named something like "wsbpel-v20-rddl.html" -- it should at least 
contain the string 'rddl' and end in '.html'; other than that I think we're 
ready to go!

 

Regards,

 

Mary

 

  

  
  From: Diane Jordan [mailto:] 
  
Sent: Wednesday, August 23, 2006 11:04 PM
To: Robin 
  Cover; ; 
Cc: 
  
Subject: WS BPEL URIs for 
  RDDLs, WSDLs, Schemas, etc

  

Hi, 
Today the TC approved a new committee draft and the 
  start of public review.  Alex asked that I follow up with you to confirm 
  that the approach he described below is ok.   
Please let us know.  
Regards, Diane
IBM 
   Emerging Internet Software Standards

(919)254-7221 
  or 8-444-7221, Mobile: 919-624-5123, Fax 845-491-5709

----- Forwarded by Diane 
  Jordan/Raleigh/IBM on 08/23/2006 11:02 PM ----- 

  
    
    

      Alex Yiu 
        <> 
        
08/16/2006 09:46 PM 

      
        
          
          

            
              
To

            Robin Cover 
              <> 
          

            
              
cc

            "Marin, Mike" 
              <>, Thomas Schulze 
              <>, Diane Jordan/Raleigh/IBM@IBMUS, 
              Mary McRae <>, bpel spec 
              <>, Prasad Yendluri 
              <>, Alex Yiu 
              <> 
          

            
              
Subject

            Re: [wsbpel-spec-edit] Re: URIs 
              for RDDLs, WSDLs, Schemas, etc

        
          
          

            
            

Hi Robin,

Thanks for the quick reply.
If I understand 
  your email correctly, a file arrangement based option [c] listed in my 
  previous email should be OK to OASIS convention. Let me re-iterate the details 
  of file arrangement again here:

For the following 5 URLs 
  (with or without the trailing '/'), transparent ('raw') 
  directory listings will be shown: 
http://docs.oasis-open.org/wsbpel/2.0/process/abstract
http://docs.oasis-open.org/wsbpel/2.0/process/executable
http://docs.oasis-open.org/wsbpel/2.0/plnktype
http://docs.oasis-open.org/wsbpel/2.0/serviceref
http://docs.oasis-open.org/wsbpel/2.0/varprop

There will be 5 XSDs uploaded to the above directory locations 
  as well. 

Similarly, the following URL (with or without the 
  trailing '/'), transparent ('raw') directory listings will be 
  shown: 
http://docs.oasis-open.org/wsbpel/2.0

In the above "/wsbpel/2.0" directory, we will have the 
  following files: 
  
    
a PDF file for the spec text 
    
a HTML file for the spec text 
    
an index.html (which is an XHTML+RDDL document) to document 
    all resources provided by this spec (e.g. PDF + HTML + 5 XSDs). And, we 
    document the 5 XSD resources, we may use the following pattern: 
  
(Suggested) prefix |  Namespace URI | 
  Schema Location URI 

I hope I document our 
  current intent of directory usage right. If the above usage is acceptable to 
  OASIS convention, please confirm. 

And, I don't have a strong 
  opinion to add additional XHTML+RDDL documents in 5 XSD directories. One way 
  or the other is OK to 
  me.

Thanks!

Regards,
Alex 
  Yiu

Robin Cover wrote: 
On Wed, 
  16 Aug 2006, Alex Yiu wrote:
  
Hi 
  Robin,

(BTW, I work in OracleJSP engine for a number of years, before 
  starting
doing BPEL work. Hence, I have some basic knowledge on 
  Apache
integration and includiing its mod.)
    
  

Excellent... you're in a great position to advise us, 
  then, as OASIS
staff attempts to identify optimal solutions using the 
  Apache
server directives.  That's a moot point for the moment: the IT 
  staff
needs to unravel some configuration dependencies, maybe upgrade 
  from
Apache 1.3 to Apache 2.x, and then implement real solutions to 
  replace
our current adhocery.  Meantime, we are stuck with Apache 
  default
behaviors (Apache 1.3).

  
*[a]*
Just to clarify:
I guess WS-RX is using a handcraft 
  "index.html" that has a META HTML
refresh tag to perform the redirect, 
  instead of mod_rewrite or mod_alias
in Apache. And, META HTML refresh tag 
  is not preferred for some reason.

Is my understanding correct so 
  far?
    

Yes. The redirect 
  as implemented creates too much traffic, confuses
some pieces of software, 
  and has the undesirable effect of populating
the browser address window 
  with the URI for the RDDL document
instead of retaining the NS 
  URI.

What we want (per some discussions with our web architecture 
  experts)
is more akin to what one observes in connection with NS URIs 
  and
RDDLs as used by W3C and the (WS-*) xmlsoap.org web 
  sites.

Contrast (A) the behavior exhibited in connection with these NS 
  URIs

- http://www.w3.org/2000/svg
- http://schemas.xmlsoap.org/ws/2004/09/transfer
- http://www.w3.org/2003/05/soap-envelope
- http://www.opengis.net/gml

[the NS URI or the related directory URI remain visible in 
  the
browser address window when the NS URI is dereferenced]

with (B) 
  at WS-RX TC web site:

http://docs.oasis-open.org/ws-rx/wsrm/200510

/* when dereferenced, repopulates address window with 
   */

http://docs.oasis-open.org/ws-rx/wsrm/200510/wsrm-1.1-rddl-cd-02.html

We think "(A)" is what users expect, not "(B)". The RDDL is 
  designed
for humans as well as machines, but when humans are looking 
  for
information about a namespace (URI) via a namespace document, 
  it
seems far preferable to have the namespace URI displayed in 
  the
window when the human user is viewing the RDDL information. 
   We
intend, provisionally, to recommend a solution that 
  resembles
the behavior for this NS URI:

  http://www.w3.org/2000/svg

  
*[b]*
Questions:
Would it be more acceptable that the 
  "index.html" itself located in a
number directory is the XHTML+RDDL 
  content? (i.e. no meta html refresh
or redirect business)
  
    

I can understand why you'd propose 
  that, and arguably it's more
acceptable than what we now implement for 
  WS-RX (wsrm).

On the other hand, one of the key design goals for the 
  OASIS Open
Library (http://docs.oasis-open.org/) is 
  to make the file system
contents transparent to users. That goal is 
  motivated by several
features we want to implement, like "please ZIP up the 
  contents
of this directory (recursively) and let me download the 
  whole
collection of files as one ZIP file".  For these kinds of 
  operations,
we need to allow the users to see what's on the file system. 
   Our
plan is to use the most informative "fancy" index page 
  navigation
that Apache will support, augmented perhaps with some 
  related
file system navigation/browse tools.  In any case, we need to 
  be
able to present unfiltered directory listings.

Thus, in the 
  naming guidelines (approved but not yet announced)
we express this in the 
  words: "TC members must not create filenames that
compete with any reserved 
  filenames used by the system/server or by OASIS
staff for administrative 
  purposes... File names reserved for (future)
administrative use include any 
  files significant to the Apache server
(e.g., .htaccess; *.cgi; *.conf or 
  matching any Apache config files;
mime.types) and files used by Staff for 
  uniform browsing/navigation (e.g.,
index.html, index.htm, etc). A complete 
  list must be provided..."  See:
http://docs.oasis-open.org/specGuidelines/namingGuidelines/resourceNaming.html#nameConstruction

  
*[c]*
If suggestion 
  in [b] is not preferred, I would personally want to see a
"raw directory" 
  listing. (similar to
http://docs.oasis-open.org/wss/2004/01/ )  in 5 directories for XSD:
http://docs.oasis-open.org/wsbpel/2.0/process/abstract
http://docs.oasis-open.org/wsbpel/2.0/process/executable
http://docs.oasis-open.org/wsbpel/2.0/plnktype
http://docs.oasis-open.org/wsbpel/2.0/serviceref
http://docs.oasis-open.org/wsbpel/2.0/varprop
    

As described 
  earlier, a design goal for the OASIS Open Library is to
always provide 
  transparent ('raw') directory listings: we want users to
be able to see 
  everything.  So yes, the "raw directory" listing is
very acceptable as 
  part of the solution.

  
We will 
  have only one  XHTML+RDDL as the index.html at the top 
  level
directory:
http://docs.oasis-open.org/wsbpel/2.0
    

It sounds like 
  you want to document the five (5) NS URIs in one
(RDDL) namespace document 
  -- right?  In that case, all five
NS URIs, when dereferenced, will 
  resolve to [the resource
represented by] that single XHTML+RDDL 
  file.

Based upon what I've explained so far, you can predict my 
  answer
to the proposal that "index.html" [ /wsbpel/2.0/index.html ]
be 
  used as the filename for the RDDL: that would be OK, but we
would want to 
  override the default Apache behavior to ensure that
we display the 
  directory listing when a request is made for
either of these 
  resources:

a) http://docs.oasis-open.org/wsbpel/2.0
b) http://docs.oasis-open.org/wsbpel/2.0/

Viz., we would not (want to) display the contents of 
  the
file .../wsbpel/2.0/index.html when a user (agent) makes
an HTTP 
  request for "a)" or "b)" immediately above

  
  

What we want to achieve in [b]/[c] is:
given a NS 
  URI (e.g.
http://docs.oasis-open.org/wsbpel/2.0/process/executable ),
people can locate its XSD very quickly from http://docs.oasis-open.org
web site.
    

That's a very reasonable goal, IMO.

Some designs actually 
  resolve directly to the schema file when the
NS URI is dereferenced. 
   I don't want to explain here why I think
that's a bad idea.

I 
  think you can design the RDDL document to provide a highly visible
mapping 
  from NS URI to the schema (location) URI.  For example,
you could 
  create an HTML table at the very top of the RDDL document
which displays. 
   Table header:

(Suggested) prefix |  Namespace URI | Schema 
  Location URI

Visually, the relatiohships would be very clear, and the 
  user
can click on any of the (hyperlinked) Schema Location URIs

** 
  Unfortunately, there's little consensus as of yet about the
structure of 
  RDDL documents in support of machine-to-machine use.

  
  
If we select the schema location suggested by your first 
  email this
morning, e.g.,
http://docs.oasis-open.org/wsbpel/2.0/schemas/wsbpel_abstract_common_base.xsd
http://docs.oasis-open.org/wsbpel/2.0/schemas/wsbpel_executable.xsd
http://docs.oasis-open.org/wsbpel/2.0/schemas/wsbpel_plnktype.xsd
http://docs.oasis-open.org/wsbpel/2.0/schemas/wsbpel_serviceref.xsd
http://docs.oasis-open.org/wsbpel/2.0/schemas/wsbpel_varprop.xsd

Then, it will be actually harder for people to locate the 
  file.
    

I can see why 
  you'd say that. So I believe the RDDL is the best
solution to the problem 
  of making it easy to locate a schema file
if they the NS URI: just 
  dereference the NS URI, and see the
(hyperlinked) schema URI at the top of 
  the RDDL document.

  
And, if 
  there is a need for an errata for XSD, we can upload the errata
version of 
  XSD to the same directory. That will mirror similar efforts
for 
  "http://schemas.xmlsoap.org/wsdl/"
    

It appears that 
  the downside of the 'xmlsoap.org' design is that we
cannot detect what 
  resources are in the '/wsdl/' directory (assuming
that there is a /wsdl/ 
  direcory).  We want to maximize the visibility
of all resources by 
  exposing the file system.

  
Please let me know whether [b] or [c] is more feasible for you 
  guys.
    

I'll discuss the 
  details with Mary McRae.  Meantime, perhaps you can
reflect on the 
  notion that creative use of your RDDL document is
indeed the more natural, 
  effortless, and predictable way of
helping a user get from the NS URI to 
  the Schema location URI.

  

Thanks!

Regards,
Alex 
  Yiu

Robin Cover wrote:

    
  
Thanks, Alex.

Alas, I have not been fast enough in 
  my communications.

The example provided from the existing 
  implementation of
WS-RX TC NS URIs is not a good example.  It 
  represents the
state of affairs as initially requested by the WS-RX 
  TC,
but in subsequent conversations with the (relevant)
TC members, it 
  was admitted/agreed that the OASIS
implementation at the server 
  level

a) using special hand-crafted index files
b) with META refresh 
  redirects
c) which brings the RDDL document URI into the browser 
  adddress
 window when the NS URI is dereferenced

is neither 
  desirable nor optimal.

Hence, my message of earlier 
  today:

 Subject: URIs for RDDLs, WSDLs, Schemas, 
  etc
 Message-ID: <>

urged your TC to consider a different strategy which does 
  NOT
locate the schema files in the proposed directories -- since the
NS 
  URI is in effect overloaded.

If you want to follow the example used 
  (currently) for the WS-RX
TC, that's OK, but please realize:

a) we 
  cannot recommend that solution as optimal or desirable
b) we intend to fix 
  the implementation in the WS-RX TC as soon as
 we get OASIS IT support 
  -- viz., it will then NOT work
 in the manner you now observe
c) we 
  intend to fix a couple related implementations that use the
 (crude, 
  kludge, hack META refresh redirect mechanism)
d) the ebxml-bp TC members 
  initially requested an implementation of
 the NOT-recommended type, 
  and we are in the midst of a
 painful process to correct that 
  situation by reduplicating
 files to a new directory where they can be 
  listed using
 standard/default Apache indexing

So you 
  say:

"If the pattern is feasible for WS-RX, it should work for us 
  also."

to which I need to reply:  "the WS-RX TC pattern is not a 
  good
implementation pattern to follow," even if it's "feasible"
in the 
  sense of being nominally functional.

I am very proud of the pioneering 
  work done on RDDLs by Marc
Goodner, Chris Ferris, Paul Cotton, and others 
  in the WS-RX
TC.  Unfortunately, we were unable to provide an 
  optimal
implementation at the server level.  We are trying to 
  avoid
further problems by asking TCs to consider an alternate
pattern 
  for schema location.  The server implementation
(I would characterize 
  as a crude hack) is not something
the WS-RX members envisioned or 
  requested: it is the
temporary solution provided by OASIS staff.

In 
  any case, when OASIS IT provides the requested support
for Apache 
  redirects, we will continue to deliver a (RDDL)
namespace document when the 
  namespace URI is dereferenced.
However, the implementation will be a lot 
  cleaner, and will
avoid some of the (reported) DNS/HTTP resolution 
  problems
associated with the current implementation.  Using
the 
  appropriate Apache directives will also allow us to
override the default 
  Apache redirect problem described in
my note earlier today.

I 
  apologize that I was unable to dive into this 
  discussion
earlier.

Thanks.

Robin Cover

On Wed, 16 Aug 
  2006, Alex Yiu wrote:

      
  
Hi Robin,
(cc'ing Prasad and wsbpel-spec-editing 
  list)

Thanks for your email.

Robin 
  wrote:

        
a) Directory URI: http://docs.oasis-open.org/wsbpel/2.0/process/abstract/
b) NS URI: http://docs.oasis-open.org/wsbpel/2.0/process/abstract

The current default server behavior is to issue a redirect from 
  "b)" to "a)" when a user (agent) requests the resource at "b)".  This 
  default handling makes it impossible to produce a (raw, Apache-generated) 
  directory listing for the contents of the "abstract" directory because 
  dereferencing the NS URI needs to produce the associated RDDL namespace 
  document. Given our existing limitations, there's no way to get Apache to list 
  the directory contents, because the URI is 
  overloaded.

          
  
Not being able to produce a (raw, Apache-generated) 
  directory listing is
fine to me. We don't need a raw directory listen, if 
  we got a XHTML+RDDL
document already. That document is a better way to 
  explain the content
of that directory.

Let me re-iterate my 
  viewpoint so far by lookin into Mary's WS-RX example:

schema location 
  =
http://docs.oasis-open.org/ws-rx/wsrm/200510/wsrm-1.1-schema-200510.xsd
targetNamespace =
"http://docs.oasis-open.org/ws-rx/wsrm/200510"

When people try to use a brower (user-agent) to 
  access
"http://docs.oasis-open.org/ws-rx/wsrm/200510" or
"http://docs.oasis-open.org/ws-rx/wsrm/200510/"
it will be redirected to the landing page with 
  RDDL:
"http://docs.oasis-open.org/ws-rx/wsrm/200510/wsrm-1.1-rddl-cd-02.html"

The above pattern fits our need also in general.

If the 
  pattern is feasible for WS-RX, it should work for us also.

We just need 
  SIX landing-page (XHTML+RDDL) with the following location:

One for the 
  top level:
http://docs.oasis-open.org/wsbpel/2.0

Five for 5 XSD:
http://docs.oasis-open.org/wsbpel/2.0/process/abstract
http://docs.oasis-open.org/wsbpel/2.0/process/executable
http://docs.oasis-open.org/wsbpel/2.0/plnktype
http://docs.oasis-open.org/wsbpel/2.0/serviceref
http://docs.oasis-open.org/wsbpel/2.0/varprop

What do you guys 
  think?

Thanks!

Regards,
Alex 
  Yiu

Robin Cover wrote:

      
    
Alex (and others),

Based upon a 
  posting of 14 Aug 2006 [1] and subsequent
off-list email messages, I 
  understand that the five
namespace URIs are to be:

http://docs.oasis-open.org/wsbpel/2.0/process/abstract
http://docs.oasis-open.org/wsbpel/2.0/process/executable
http://docs.oasis-open.org/wsbpel/2.0/plnktype
http://docs.oasis-open.org/wsbpel/2.0/serviceref
http://docs.oasis-open.org/wsbpel/2.0/varprop

I see no problems at all with these namespace URIs.

The 
  posting from 14 Aug 2006 also identifies five
corresponding schema location 
  URIs, which (adjusted for
the ws-bpel -->> wsbpel change) would 
  be:

http://docs.oasis-open.org/wsbpel/2.0/process/abstract/wsbpel_abstract_common_base.xsd
http://docs.oasis-open.org/wsbpel/2.0/process/executable/wsbpel_executable.xsd
http://docs.oasis-open.org/wsbpel/2.0/plnktype/wsbpel_plnktype.xsd
http://docs.oasis-open.org/wsbpel/2.0/serviceref/wsbpel_serviceref.xsd
http://docs.oasis-open.org/wsbpel/2.0/varprop/wsbpel_varprop.xsd

If the TC wants to insist on these URIs, I believe the 
  OASIS
IT Staff can adjust to that decision, and provide normal
but 
  minimal server support for the resources represented by
the five files at 
  the implied file system locations.

However, for consistency in OASIS 
  operations, it would be
preferable NOT to store the schemas in the file 
  system
locations implied by the URIs above, but rather, to store them
in 
  a separate directory. For example, the five schemas
could be stored in a 
  directory /schemas/, resulting in this
set of URIs:

http://docs.oasis-open.org/wsbpel/2.0/schemas/wsbpel_abstract_common_base.xsd
http://docs.oasis-open.org/wsbpel/2.0/schemas/wsbpel_executable.xsd
http://docs.oasis-open.org/wsbpel/2.0/schemas/wsbpel_plnktype.xsd
http://docs.oasis-open.org/wsbpel/2.0/schemas/wsbpel_serviceref.xsd
http://docs.oasis-open.org/wsbpel/2.0/schemas/wsbpel_varprop.xsd

Let me explain why this would be preferable from the 
  OASIS
point of view.

At the current time, the OASIS servers 
  associated with the Internet
domains www.oasis-open and 
  docs.oasis-open.org use configurations
which are interdependent, and are 
  tuned to reflect different needs
in Kavi and non-Kavi resources. That means 
  the IT programming team
cannot, at this time, provide the ideal form of 
  support for
server behavior when an HTTP scheme URI is dereferenced. For 
  example,
at this time if the following namespace URI is to be 
  supported,

http://docs.oasis-open.org/wsbpel/2.0/process/abstract

we would create a directory "abstract" beneath the 
  directory
"process", yielding the following two URIs:

a) Directory 
  URI: http://docs.oasis-open.org/wsbpel/2.0/process/abstract/
b) NS URI: http://docs.oasis-open.org/wsbpel/2.0/process/abstract

The current default server behavior is to issue a redirect from 
  "b)"
to "a)" when a user (agent) requests the resource at "b)". 
   This
default handling makes it impossible to produce a (raw, 
  Apache-
generated) directory listing for the contents of the 
  "abstract"
directory because dereferencing the NS URI needs to produce 
  the
associated RDDL namespace document. Given our existing 
  limitations,
there's no way to get Apache to list the directory 
  contents,
because the URI is overloaded.

I must clarify that under 
  ideal conditions, server configuration
tools should allow the IT 
  programming team to implement some
"non-default" server behavior using 
  Apache directives (e.g.,
mod_rewrite, mod_alias, mod_dir ) which would 
  avoid the
redirect from "b)" to "a)" and so forth. [2]

For these 
  reasons, and for some broad concerns for usability in
our OASIS context 
  (desire for transparent access to the web
server's file system), it's 
  better not to store content (files,
directories, symlinks, etc) in 
  directories matching these URIs:

http://docs.oasis-open.org/wsbpel/2.0/process/abstract/
http://docs.oasis-open.org/wsbpel/2.0/process/executable/
http://docs.oasis-open.org/wsbpel/2.0/plnktype/
http://docs.oasis-open.org/wsbpel/2.0/serviceref/
http://docs.oasis-open.org/wsbpel/2.0/varprop/

If the specification includes WSDL files, RDDL files, 
  and
perhaps other files associated with the prose document(s)
and XML 
  schemas. it would be better to store those files
(WSDLs, RDDLs, XML 
  schemas) in one or more separate
directories other than in the five 
  referenced immediately
above.

We can arrange a phone call to discuss 
  details further, if
that might prove useful.  I would also like to see 
  the complete
listing of files associated with version 2.0 of the 
  Web
Services Business Process Execution Language spec.

Robin 
  Cover

PS  You may forward this message to anyone on the 
  design/editorial
team.

[1] http://lists.oasis-open.org/archives/wsbpel/200608/msg00051.html
 Subject: Issue - 289 - Proposal to vote
 * From: Alex 
  Yiu <>
 * To: wsbpeltc <>
 * Date: Mon, 14 Aug 2006 13:25:18 -0700

[2] Apache 
  modules

http://httpd.apache.org/docs/2.0/mod/mod_rewrite.html
http://httpd.apache.org/docs/2.0/mod/mod_alias.html
http://httpd.apache.org/docs/2.0/mod/mod_dir.html
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