[glue-wg] LDAP Rendering

[David Horat]

Nice to know. I will make an entry about it in the wiki. :)

On Mon, Mar 30, 2009 at 6:58 PM, Paul Millar <paul.millar at desy.de> wrote:

> On Wednesday 25 March 2009 16:57:41 Maarten Litmaath wrote:
> > > - Since our specifications is relational and LDAP is NOT relational, I
> > > am still unsure how to implement this properly in LDAP. I am used to
> >
> > We probably will have to resort to "tricks" as used in GLUE 1.x.
> > For example, an object can refer to a logical parent via a ChunkKey
> > and to an object with a different ancestry through a ForeignKey.
> > As we are still defining the LDAP rendering, we might invent further
> > such notions as needed or desirable (e.g. for clarity or elegance).
>
> Please be aware that, for some time now, there is support for "extensible
> queries" (see RFC 4515).  This removes the need for GlueChunkKey.
>
> For example, to query all GlueSAPath attributes (of objects with
> objectClass
> GlueSA) that are children of SE "se.ngcc.acad.bg"
> (GlueSEUniqueID=se.ngcc.acad.bg), one could conduct the following query,
> which uses GlueChunkKey:
>
> ldapsearch -LLL -x -H ldap://lcg-bdii.cern.ch:2170/ -b
> o=grid '(&(objectClass=GlueSA)(GlueChunkKey=GlueSEUniqueID=se.ngcc.acad.bg
> ))'
> GlueSAPath
>
> However, the same result is obtained without the ChunkKey by using the
> ":dn:="
> extensible query:
>
> ldapsearch -LLL -x -H ldap://lcg-bdii.cern.ch:2170/ -b
> o=grid '(&(objectClass=GlueSA)(GlueSEUniqueID:dn:=se.ngcc.acad.bg))'
> GlueSAPath
>
> IIRC, there was an argument for continuing to support GlueChunkKey in Glue
> v1.3 to allow legacy queries.  Moreover, (afaik) there was never an
> official
> document describing the LDAP binding for GLUE v1.3 (so nothing to update
> ;-)
>
> A reason to stop using GlueChunkKey is it's provides the info-providers the
> opportunity to publish inconsistent information.  Instead, the extensible
> query is always consistent (unless there's a bug in the server software).
>
> Since, GLUE v2.0 is not meant to be backward compatible, I'd say we can
> safely
> drop GlueChunkKey in favour of the safer ":dn:=" style queries.
>
> HTH,
>
> Paul.
>
>


-- 
David Horat
Software Engineer specialized in Grid and Web technologies
IT Department – Grid Deployment Group
CERN – European Organization for Nuclear Research » Where the web was born
Phone +41 22 76 77996

http://davidhorat.com/
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