Unfortunately the xrootd protocol does not work as expected in dcache. The
idea was to use a conventional SE to store all the data for Tier2 and also
serve files to the Tier3... I don't know if Lustre implements an xrootd door
as well, maybe in a few months I'll try that.
On Wednesday 20 February 2008 11:40, Fabrizio Furano wrote:
> Hi Pablo,
> that's very interesting, and I agree completely with your conclusion,
> i.e. in most cases the lan data access is more efficient and scales
> better with respect to local disk access. Many times this is not very
> well understood by people, always striving to keep local files at any cost.
> It would be very interesting to have a comparison between the
> performance in proof between a dcache storage and an analogous xrootd
> storage, which is the default solution for that. With the same pool of
> workers of course.
> From what I've understood, dcache uses a read ahead mechanism (at the
> client side), while xrootd uses a scheme which is mixed with informed
> async prefetching.
> Pablo Fernandez ha scritto:
> > Hi all,
> > I would like to share with you some information about my testings of
> > performance in Proof with different storage schemas.
> > http://root.cern.ch/phpBB2/viewtopic.php?t=6236
> > I have translated this topic to the Proof Forum since seems to me more
> > Proof-related than just xrootd, I hope you don't mind.
> > BR/Pablo
Pablo Fernandez Fernandez e-mail: [log in to unmask]
Dpto Fisica Teorica. C-XI.
Facultad de Ciencias
Universidad Autonoma de Madrid. Phone: 34 91 497 3976
Cantoblanco, 28049 Madrid, Spain. Fax: 34 91 497 4086