Hi Omer, Each grid is currently using a different discovery mechanism. This aim of the SAGA work is to provide an API which hides these differences and enables the user to discover resources in all grids. I believe this is the functionality which Gerson was talking about. Standardizing the discovery methods is something that we should look into and the mechanisms used in many P2P systems should definitely be investigated. Laurence The SAGA effort is trying to Omer F. Rana wrote:
Hi Laurence,
Have you looked at the discovery mechanisms found in peer-2-peer systems -- which are much more likely to scale? There has been work in integrating P2P concepts with directory services also.
My understanding of SAGA effort is that they identify that a discovery service is necessary -- but not how the actual discovery mechanism works (as this is outside, surely, the scope of SAGA)?
regards Omer
Laurence Field wrote:
Hi Gerson,
A common information system client would bets fit will with the SAGA work. They are already working on an API for Service discovery which will use plugins to find information from the different grids.
The OGSA Information Services group is currently looking it existing technologies used in information systems. Your experiences with MDS4 and XPath would be valuable input to this group. Do you have anything available which documents your experiences?
Thanks
Laurence
Gerson Galang wrote:
Hi all,
I don't have anything against having another layer sitting on top of all different Grid information systems implementation but I'm just not sure if that model will scale.
I got interested in this discussion because I'm developing an application which is somewhat related to what I'm going to recommend below. The application is being developed for the Australian Grid users and developers and is going to be used in querying an MDS4 index service which uses the GLUE 1.2 schema. We have specified our own query language for querying the information system because we didn't want developers to write XPath queries if they directly interact with MDS4. As you know a very simple resource condition in an info systems query can turn out to be a very long query string when converted into XPath especially XPath 1.1 which is what MDS4 only understands.
This group should probably look into implementing a similar generic Grid info systems client application for all the Grid info systems implementations around the world. Since the plan is to use the GLUE schema, there won't be any issues with specifying a standard query language that users can use with this client. The client will need to be able to query a "registry of endpoints" service to get information about the endpoint, query implementation (eg. wsrf/mds4, mds2, etc), and the query language (xpath, xquery, ldap, sql) to use for the info systems. The client will be the one in charge of transforming the user's query into the respective query languages used by the different Grid information systems implementations. I think we'll get a quicker response if we query the "registry of endpoints" service than the top level information system which indexes all the Grid resource information around the world.
Our application can only handle a very simple query at the moment. See link below..
https://www.grid.apac.edu.au/repository/svn/infosystems/GlueSchemaQueryLib/R... <https://www.grid.apac.edu.au/repository/svn/infosystems/GlueSchemaQueryLib/README>
but we have plans of extending the language later on to support queries like "(Site.Latitude > 0 and Site.Latitude < 50)". Composing a query for the GLUE schema shouldn't be that hard. The only thing which makes the query complicated is the language we use in querying the Grid info systems.
I'm just not sure if what we are implementing is something you would want to look into.
Regards, Gerson
On 8/4/07, *Andreas Savva* <andreas.savva@jp.fujitsu.com <mailto:andreas.savva@jp.fujitsu.com>> wrote:
The presentation Ravi is referring to is https://forge.gridforum.org/sf/go/doc14456?nav=1 <https://forge.gridforum.org/sf/go/doc14456?nav=1>
Subramaniam, Ravi wrote: > Hi Hiro/Felix, > > Currently the examples in the document are from "academia" (not that I > am against that as most who know me will attest) but in the spirit of > including enterprise examples would it make sense to include the > implementation that I presented at the OGSA F2F in Manchester as an > example for the enterprise case? > > Ravi > > -----Original Message----- > From: ogsa-wg-bounces@ogf.org <mailto:ogsa-wg-bounces@ogf.org> [mailto:ogsa-wg-bounces@ogf.org <mailto:ogsa-wg-bounces@ogf.org>] On Behalf > Of Hiro Kishimoto > Sent: Wednesday, August 01, 2007 2:49 PM > To: ogsa-wg > Cc: glue-wg@ogf.org <mailto:glue-wg@ogf.org> > Subject: Re: [ogsa-wg] OGSA Information Services > > Hi all, > > Per Felix's request, I've upload revised draft onto the GridForge. > > https://forge.gridforum.org/sf/go/doc14692 > > We will discuss it at Thursday's call. > > Thanks, > ---- > Hiro Kishimoto > > -------- Original Message -------- > Subject: Re:[ogsa-wg] OGSA Information Services > From: Hiro Kishimoto < hiro.kishimoto@jp.fujitsu.com <mailto:hiro.kishimoto@jp.fujitsu.com> > > To: ogsa-wg <ogsa-wg@ogf.org <mailto:ogsa-wg@ogf.org>> > Cc: felix.ehm@cern.ch <mailto:felix.ehm@cern.ch> > Date: 2007/07/26 12:55 > >> Hi all, >> >> Discussion material for Information Services by Laurence Field and >> Felix Ehm is now on the GridForge. >> >> https://forge.gridforum.org/sf/go/doc14692 <https://forge.gridforum.org/sf/go/doc14692> >> >> > This document covers the problem description, experience in GIN, > > >> overview of existing systems, generalized system and suggested > >> areas for standardization. >> >> Please have a look before the call today. >> >> Felix Ehm will lead the discussion. >> >> Thanks, >> ---- >> Hiro Kishimoto >> >> >> -- >> ogsa-wg mailing list >> ogsa-wg@ogf.org <mailto:ogsa-wg@ogf.org> >> http://www.ogf.org/mailman/listinfo/ogsa-wg <http://www.ogf.org/mailman/listinfo/ogsa-wg> >> >> > > -- > ogsa-wg mailing list > ogsa-wg@ogf.org <mailto:ogsa-wg@ogf.org> > http://www.ogf.org/mailman/listinfo/ogsa-wg <http://www.ogf.org/mailman/listinfo/ogsa-wg> > _______________________________________________ > glue-wg mailing list > glue-wg@ogf.org <mailto:glue-wg@ogf.org> > http://www.ogf.org/mailman/listinfo/glue-wg <http://www.ogf.org/mailman/listinfo/glue-wg>
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