Hi Fabrizio,
so the memory depends on how well the files are distributed and the
replicas?
I have 1000 nodes (2000 cpus). I can well think that it will never
happen that 1999 processes try to access 1 xrootd instance. But it might
be over 100. I guess it is matter of tuning.
cheers
alessandra
Fabrizio Furano wrote:
> Hi Alessandra,
>
> typically the memory needs of a server are proportional to the number
> of clients and to the ongoing activity rates. For a small number of
> clients (let's say 1-100) the memory needs are quite low. I've done many
> many stress tests in a pIII machine with 256 megs with no problems at
> all. The memory becomes an important parameter when you plan thousands
> of clients per server.
>
> Fabrizio
>
> Alessandra Forti wrote:
>> Apologies that worries me in using xrootd on the WNs....
>> I'm a bit confused right now :(
>>
>> Alessandra Forti wrote:
>>> Hi Peter,
>>>
>>> after yesterday I also remember that the second thing that worried me
>>> in using dcache on the WN is a comment Andy made about the use of
>>> memory in his talk at CHEP I believe. He said it xrootd uses a lot of
>>> memory but there weren't number specified.
>>>
>>> My system is double cpu with 2GB of memory per cpu. Considering that
>>> an atlas job can use more than 1 GB we are now at 1.1 I thik. Will it
>>> be enough? I think so but I just wanted to check.
>>>
>>> cheers
>>> alessandra
>>>
>>>
>>> Peter Elmer wrote:
>>>> Hi All,
>>>>
>>>> There is now a new xrootd development version: xrootd
>>>> 20060523-1741, please see:
>>>> http://xrootd.slac.stanford.edu/download/20060523-1741/
>>>>
>>>> for downloads.
>>>>
>>>> Relative to the last development build (20060418-0404) this
>>>> includes a variety of small bug fixes, plus one important one for
>>>> the redirector. See
>>>> the xrootd.History file for more details. I've included a link to the
>>>> SL3 debuginfo rpm on the rpm page. (Although I've not tried it myself,
>>>> so I have no idea if it works! Feedback is welcome.)
>>>>
>>>> Gerri, if it is still possible, you could add this to the next ROOT
>>>> build, too.
>>>>
>>>> For the full set of changes and links to rpms/tarballs to
>>>> download see the
>>>> the xrootd web page and/or version history:
>>>>
>>>> http://xrootd.slac.stanford.edu
>>>> http://xrootd.slac.stanford.edu/xrootd.History
>>>>
>>>> Let us know if there are problems.
>>>>
>>>> Pete
>>>>
>>>> -------------------------------------------------------------------------
>>>>
>>>> Peter Elmer E-mail: [log in to unmask] Phone: +41 (22)
>>>> 767-4644
>>>> Address: CERN Division PPE, Bat. 32 2C-14, CH-1211 Geneva 23,
>>>> Switzerland
>>>> -------------------------------------------------------------------------
>>>>
>>>
>>
--
*******************************************
* Dr Alessandra Forti *
* Technical Coordinator - NorthGrid Tier2 *
* http://www.hep.man.ac.uk/u/aforti *
*******************************************
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