Hi Jan,
Actually, that is there already. A file query sent to a server will
automatically update the access time of the file without you having to
open the file. So, a prepare will do the same thing.
Andy
On Fri, 19 Oct 2007, Jan Fiete Grosse-Oetringhaus wrote:
> Hi Andy, hi Fabrizio,
>
> our 'ALICE data stager daemon' now takes care of about 100.000 files on our
> PROOF cluster. The daemon regularly checks that all files are still staged to
> the system and sends staging requests for missing ones. For keeping the files
> on the cluster each file is touched regularly. This prevents the garbage
> collection (that runs per machine) to remove the files.
>
> The daemon runs in ROOT and to actually touch the file, the file has to be a)
> opened and b) at least 1 byte read. This runs sequentially and can process
> about 30 files per second. For 100.000 files this amounts to roughly one
> hour, which is quite some time. The number of files might increase by another
> order of magnitude.
>
> Therefore I wanted to suggest the introduction of a "touch" command in xrootd
> that would preferably be even offered as bulk command.
>
> What do you think?
>
> Best regards,
> Jan Fiete
>
> --
>
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>
> Jan Fiete Grosse-Oetringhaus
>
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