Hi Alessandra,
He needs supervisors because he has more than 64 data nodes. You will need
them too. Everything is explained in
http://xrootd.slac.stanford.edu/doc/olb_config_050601/olb_config.htm
in the introduction section.
Andy
----- Original Message -----
From: "Alessandra Forti" <[log in to unmask]>
To: <[log in to unmask]>
Cc: <[log in to unmask]>
Sent: Wednesday, May 24, 2006 7:12 AM
Subject: Re: New xrootd development version 20060523-1741 available
> Hi,
>
> I see you have a 3 tiers hierarchy: redirector, supervisors and
> workernodes. What is a supervisor? Other configurations don't seem to have
> this layer. Can supervisors be specialised worker nodes? What is olbd? and
> finally is the software for redirector supervisors and data servers the
> same (i.e. I install the same rpm) but configured differently? Why are you
> using 2 xrootd instances per WN? Have you bound each with a different
> partition? Or do they both serve all the available partitions.
>
> Apologies for all these questions you'll have to bear with me until I get
> up o speed.
>
> thanks
>
> cheers
> alessandra
>
> Pavel Jakl wrote:
>> Hello,
>>
>> Yes, it is. But the plot is showing sum of usage at production and
>> development cluster. I have to split the statistics into 2 plots, sorry
>> about not giving you a proper plot.
>> I can say, that I couldn't see what Fabrizio is talking about because we
>> still don't have so many users using the xrootd. We wanted to move from
>> our old solution very slowly and see the behavior of xrootd with
>> increasing number of users as time goes. Users are switching from rootd
>> to xrootd by their choice and I can say that this process in completely
>> unclear to me :-) But the number of users is higher and higher as xrootd
>> gives more advantages.
>>
>> Cheers
>> Pavel
>>
>> Alessandra Forti wrote:
>>> Hi Pavel,
>>>
>>> thanks this is very useful. Is this the STAR production cluster? I read
>>> also that talk given at chep.
>>>
>>> cheers
>>> alessandra
>>>
>>>
>>> Pavel Jakl wrote:
>>>> Hello Alessandra,
>>>>
>>>> Andy talked mostly about scalability and performance tests of xrootd
>>>> and trying to show the behavior of xrootd at upper limits I believe. I
>>>> don't know nothing about the fact that xrootd uses a lots of memory.
>>>> We are using xrootd on WNs and we have deployed it on 320 nodes with
>>>> about 130TB. These nodes are heavily loaded by user's jobs, mostly ROOT
>>>> jobs.
>>>> For your imagination, I am sending you plots being produced by really
>>>> home-made monitoring with Ganglia toolkit.
>>>> I also need to mention, that you have to divide these numbers by the
>>>> factor of two, because we are running two instances of xrootd per node
>>>> (we have a development and production cluster). You can see that memory
>>>> usage is really, really small.
>>>>
>>>> Cheers
>>>> Pavel
>>>>
>>>> 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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