[Go-essp-tech] Reasoning for the use of symbolic links in drslib

[Gavin M. Bell]

 Gentle-people,

This is what the catalogs are for.
There is too much filesystem talk.  The filesystem can only do so much
for us.
There is semantic knowledge that is trying to be captured in a
relatively rigid tree structure.
We must out 'outside of the box', I feel we are abusing the filesystem
and trying to do gymnastics with it that we don't need to do.  The
answer is not with the filesystem.  The answer is the catalogs and 
using them appropriately.  We need to stop hedging our bets against the
system we are building and actually use it to our benefit (the reason
why we made it).  The filesystem is a red herring.

just my $0.02

I should pull out the email I wrote in November of 2009 describing the
catalog as the needed lingua fraca of this endeavor.

-Cassandra.

On 9/19/11 9:00 AM, Kettleborough, Jamie wrote:
> Hello Karl, everyone,
>
>     For replicating the latest version, I agree that your alternate
>     structure poses difficulties (but it seems like there must be a
>     way to smartly determine whether the file you already have a file
>     and simply need to move it, rather than bring it over again).   
>      
>
> Doesn't every user (not just the replication system) have this
> problem: they want to know what files have changed (or not changed) at
> a new publication version.  No one wants to be using band width or
> storage space to fetch and store files they already have.  How is a
> user expected to know what has really changed?  Estani mentions check
> sums - OK, but I don't think all nodes expose them (is this right?). 
> You may try to infer from modification dates (not sure, I haven't look
> at them that closely).  You may try to infer from the TRACKING_ID -
> but I'm not sure how reliable this is (I can imagine scenarios where
> different files share the same TRACKING_ID - e.g. if they have been
> modified with an nco tool).
>  
> Is there a recommended method for users to understand what *files*
> have actually changed when a new publication version appears?
>  
> Thanks,
>  
> Jamie

-- 
Gavin M. Bell
Lawrence Livermore National Labs
--

 "Never mistake a clear view for a short distance."
       	       -Paul Saffo

(GPG Key - http://rainbow.llnl.gov/dist/keys/gavin.asc)

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