[gin-data] On SRB interoperability with gLite

[Jensen, J (Jens)]

Just a quick update on the message below.

I did get feedback from Erwin, but not from anyone else.  If
someone is taking it off to discuss on srb lists, could you
summarise the result to gin-data please.  Ta.

Someone once told me that SRB has a GridFTP server, so I checked
with Adil Hasan and he says his, yes, and his team got it working.

As I see it, it is essential to be able to drive the SRB via
GridFTP to avoid copying files out to the client.  I.e., if copying
files from SRM A to SRB B from Client C, then you want the data
to travel from A to B, not via C.

If this is the case, then perhaps the FTS can drive the SRB like
it does Classic SEs (I am told some countries still have Classic
SEs :-)

STFC - our organisation, RAL's research council, has got all the
experience in-house, so we can play with it a bit and see what
happens.

I asked Adil to look into the GridFTP-for-SRB thing, and Matt
Hodges from Tier 1 to test the FTS-to-GridFTP.  We can then plug
it together and see if it works trivially.

Regards,
			--jens

-- 
Dr Jens Jensen
STFC Rutherford Appleton Laboratory


-----Original Message-----
From: gin-data-bounces at ogf.org [mailto:gin-data-bounces at ogf.org] On
Behalf Of Jensen, J (Jens)
Sent: 11 May 2007 07:28
To: gin-data at ogf.org
Subject: [gin-data] On SRB interoperability with gLite

Morning boys and girls.

Arun and I had a discussion yesterday on how to make SRB and
gLite interoperate.  We have discussed for a while to build
SRB interfaces to SRM, and vice versa, and this is an old
discussion, but there may be a "lower hanging fruit":

What if FTS (File Transfer Service) - which can already talk
to (at least) 3 SEs, SRM 1, SRM 2 (right?), and Classics
- added support for SRB as another SE.

Stepping back to the use case, I would think the primary customers
would be
(a) any VO which holds data in both worlds, e.g. (1st approx)
all non-HEP VOs in EGEE;
(b) Grids that wish to interoperate, like GridPP (SRM only)
and the (UK) National Grid Service NGS (SRB).

Questions.  People analysing SRB data tend to locate it and Sget
it out of SRB.  Is FTS appropriate for this.  How does it work
with the job submission workflow if an SRB file is needed
(I didn't get enough sleep to figure that one out for myself :-)

Probably a GLUE information service, say a BDII, is needed for
SRB - FTS doesn't need it directly but other tools might if they
are made SRB aware - worth thinking about now.

So it would lose metadata information from the MCAT but
perhaps a smarter egg could write something to transfer it
to something else.

Filenames.  Perhaps we now need "srm://srm.wombat.ac.uk/srm/file"
and "srb://srb.wombat.ac.uk/srb/file" SURLs.  But the GUID and
LFN stuff would work as before.

Apart from everybody thinking interoperability is good, the real
need should be identified.  We need to identify a real user who
needs real data in both worlds, and work through the use cases.
Any show of hands?

Anyway, I am just thinking out loud as usual but thought I would
suggest it so we can discuss it today.

Thanks,
--jens
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