Hi Pete,
I have been already contacted by Brian about this issue. This is
one of the reasons why the final version of the patch that has made it
to the xroot repository is sligthly different that the one you got:
the fork handlers are disabled by default and one can enable them by
setting an environment flag:
http://xrootd.cern.ch/cgi-bin/cgit.cgi/xrootd/patch/?id=953079e8605f58f0500e6b4ed774a8ed91a75671
I can also add the check suggested by Chris just to be extra careful.
Cheers,
Lukasz
2011/3/3 Peter Elmer <[log in to unmask]>:
> [Add Lukasz, Brian and xrootd dev list]
>
> Hi Lukasz, Brian, xrootd-dev,
>
> Can you take a look at and comment on Chris' suggestion below?
>
> As Brian knows we currently build the xrootd version taken from ROOT
> 5.27/06b and the patch we are applying is:
>
> http://cmssw.cvs.cern.ch/cgi-bin/cmssw.cgi/COMP/CMSDIST/xrootd-5.27.06b-forkv2.patch?revision=1.1&view=markup
>
> An updated 5.27/06b-applicable patch would be very welcome....
>
> thanks,
> Pete
>
> On Wed, Mar 02, 2011 at 06:01:53PM -0600, Chris Jones wrote:
>> I've tracked down the origin of the problem. In our xrootd5.27.06b-cms3 version of xrootd we added a modification from the xrootd developers to deal with 'fork'ing. However, when xproofd does its fork a pre-condition expected by the xrootd code does not hold and the code tries to talk to a null C++ object. However, I think this could easily be fixed by changing the file XrdClient/XrdClientEnv.cc such that before every call to 'ConnectionManager' the code first does
>> if( 0 != ConnectionManager ) { .... }
>> However this would require a new cms specific patch on xrootd.
>>
>> By the way, to get your code to work with the new ROOT you can do
>>
>> source /afs/cern.ch/sw/cms/slc5_amd64_gcc434/lcg/root/5.27.06b-cms3/etc/profile.d/init.csh
>> source /afs/cern.ch/sw/cms/slc5_amd64_gcc434/external/gcc/4.3.4-cms/etc/profile.d/init.csh
>> source /afs/cern.ch/sw/cms/slc5_amd64_gcc434/external/xrootd/5.27.06-cms/etc/profile.d/init.csh
>> xproofd -c xpd.cf
>>
>> this works without ever having to setup a CMSSW environment.
>>
>> By the way, this work was really complicated by the fact that xproofd has statically included all xrootd client code but the program still links in libXrdClient.so. We thought we had kept ROOT and xrootd separate but xproofd is within ROOT.
>>
>> Hopefully we can make a patch,
>> Chris
>>
>> Christopher Jones
>> Fermi National Accelerator Laboratory
>> [log in to unmask]
>>
>> On Feb 28, 2011, at 6:46 AM, Tomasz Fruboes wrote:
>>
>> >
>> > *** Discussion title: Framework and Edm Development
>> >
>> > Dear experts,
>> >
>> > I'm trying to run xproofd using default root installation from CMSSW_4_2_0_pre5 (slc5_amd64_gcc434) and I'm getting a segmentation fault on very beginning. Using same xproofd config file under ia32 architecture gives me good results (xproofd starts, I'm able to connect to it from root). I add "how to reproduce" and contents of my xproofd cfg file below. Could you have a look?
>> >
>> > Thank you,
>> > Tomasz
>> >
>> > #########################
>> > export SCRAM_ARCH=slc5_amd64_gcc434
>> > cmsrel CMSSW_4_2_0_pre5
>> > cd CMSSW_4_2_0_pre5
>> > cmsenv
>> > cd -
>> > xproofd -c xpd.cf
>> > (...)
>> > *** Break *** segmentation violation
>> > Segmentation fault
>> > #########################
>> >
>> > #########################
>> > export SCRAM_ARCH=slc5_ia32_gcc434
>> > cmsrel CMSSW_3_8_6
>> > cd CMSSW_3_8_6
>> > cmsenv
>> > source /afs/cern.ch/cms/slc5_ia32_gcc434/lcg/root/5.27.06b-cms3/etc/profile.d/init.sh
>> > cd -
>> > xproofd -c xpd.cf
>> > #########################
>> >
>> > ### Contents of xpd.cf ##
>> > xrd.protocol xproofd:1093 libXrdProofd.so
>> > xpd.tmp /tmp/fruboes/
>> > xpd.workdir /tmp/fruboes/wd/
>> > all.adminpath /tmp/fruboes//admin/
>> > xpd.localwrks 2
>> > #########################
>> >
>> > -------------------------------------------------------------
>> > Visit this CMS message (to reply or unsubscribe) at:
>> > https://hypernews.cern.ch/HyperNews/CMS/get/edmFramework/2707.html
>
>
>
> -------------------------------------------------------------------------
> 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
> -------------------------------------------------------------------------
>
