Hi all,
attached is yet-another-proposal for a future SAGA
extension. Please note that this proposal is not intended
to enter the SAGA API draft anytime soon - however, it would
be nice to get feedback on this early on.
Motivation:
Interfaces to information Services are _neccessary_ on
Grid Middleware Level, in order to allow informed
decisions of resource avialability, to store persitant
information about system configurations etc. Well, you
know.
On application level, a number of uses cases require (or
at least can benefit) from a interface to persistent
global information storage as well. A simple example is a
streaming server and client, where the handshaking
procedure is greatly simplified by read/write access to
such an information repository - all other solutions need
global knowledge.
In GridLab (and the GAT), we have very good experiences
with what we called the AdvertService. It allowed to
publish metadata tables (named adverts, just a list of key
value pairs really) in a globally visible name space. For
the example above, the streaming server could publich an
URL at /home/andre/my_stream_urls/test-server.url, and
attach meta data to it, such as:
"url" = "http://remote.host.net:1234/test"
"desc" = "my super service URL"
"contact" = "merzky(a)cs.vu.nl"
We used that service in a number of scenarios.
SAGA:
in SAGA, a specification of an advert service would be
trivial. In fact, the complete spec would be:
namespace saga
{
class advert implements-all name_space_entry
implements-all attributes
implements-all permissions { };
class advert-dierctory
implements-all name_space_directory
implements-all permissions { };
}
Thats all for now, really - as usual, any feedback would be
welcome :-)
Cheers, Andre.
--
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| Andre Merzky | phon: +31 - 20 - 598 - 7759 |
| Vrije Universiteit Amsterdam (VU) | fax : +31 - 20 - 598 - 7653 |
| Dept. of Computer Science | mail: merzky(a)cs.vu.nl |
| De Boelelaan 1083a | www: http://www.merzky.net |
| 1081 HV Amsterdam, Netherlands | |
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