[jsdl-wg] Question on jsdl:HostName element

[Michel Drescher]

	From: 	  Michel.Drescher at uk.fujitsu.com
	Subject: 	Various questions sourcing from external
	Date: 	28 February 2005 14:06:02 GMT
	To: 	  jsdl

Dear JSDL wranglers,

I got assigned to relay the following question to the JSDL working 
group:

1) jsdl:FileSystem
A very popular use case for this element is to mount the user's home 
directory to the execution environment.
How do I do that using JSDL?

Solution a) - "Magic interpreter"
The JSDL snippet would be
    <jsdl:FileSystem id="Home">
       <jsdl:Description>foo</jsdl:Description>
    <jsdl:FileSystem>
and the genie interpreter would recognise the id attribute to mount the 
execution user's home dir.
JDSL goes "Genie in the bottle", if I may say so. ;-)

Solution b) - Platform specific incarnation
The JSDL snippet would be
    <jsdl:FileSystem id="Home">
       <jsdl:Description>foo</jsdl:Description>
       <jsdl:MountPoint>/home/mdrescher</jsdl:MountPoint>
    <jsdl:FileSystem>
This solution lacks abstraction since I cannot resubmit that very job 
to another site where my home directory is mounted to another path 
(i.e. /users/drescher).
Brokering this job is also hardly possible even if I try to mess around 
with an incredibly large set of jsdl:Profile elements (to match all 
possible mount points for home directories).

Solution b) - adding "abstractable" directories to jsdl:FileSystemType
The JSDL snippet would be
    <jsdl:FileSystem id="Home">
       <jsdl:Description>foo</jsdl:Description>
       <jsdl:FileSystemType>home</jsdl:FileSystemType>
    <jsdl:FileSystem>
This way, JSDL would introduce the "home directory" syntactically. The 
downside is that $HOME is not a filesystem. But, then, is "tmp" always 
a different filesystem?

Solution c) - Allowing globbing in jsdl:MountPoint
The JSDL snippet could be
    <jsdl:FileSystem id="Home">
       <jsdl:Description>foo</jsdl:Description>
       <jsdl:MountPoint>{$HOME}</jsdl:FileSystemType>
    <jsdl:FileSystem>
    or something similar
This mechanism would introduce the well-known globbing mechanisms from 
PERL or the shells like tcsh, bash etc.

Solution d) - A revised jsdl:FileSystem element
I don't have any idea yet to propose, but personally, I think JSDL 
would benefit from an abstraction of file systems (like UNICORE or 
Globus provide).

Any thoughts?



Cheers,
Michel