Dcap problem

ROOT
1

Dear root experts,

I run into a problem with a root macro when trying to access a root tuple over dcap. The error message is added below. When first copying the file to a local disk, the macro runs fine.
I tried to tune the DCACHE_RA_BUFFER parameter, but to no avail.

All suggestions are welcome.

Thanks,

Olivier Devroede.

Reading dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root
Warning in TClass::TClass: no dictionary for class pair<string,bool> is available
number of entries is : 23477
event number 0
Error in TDCacheFile::ReadBuffer: error reading all requested bytes from file dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root, got 12966 of 25200
Error in TBranchElement::GetBasket: File: dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root at byte:0, branch:GenPart.e, entry:1, badread=0, nerrors=1, basketnumber=1
Error in TDCacheFile::ReadBuffer: error reading all requested bytes from file dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root, got 12448 of 24100
Error in TBranchElement::GetBasket: File: dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root at byte:0, branch:GenElec.e, entry:2, badread=0, nerrors=1, basketnumber=2
Error in TDCacheFile::ReadBuffer: error reading all requested bytes from file dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root, got 12542 of 16704
Error in TBranchElement::GetBasket: File: dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root at byte:0, branch:GenMu.e, entry:3, badread=0, nerrors=1, basketnumber=3
Error in TDCacheFile::ReadBuffer: error reading all requested bytes from file dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root, got 14024 of 21669
Error in TBranchElement::GetBasket: File: dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root at byte:0, branch:GenNu.e, entry:4, badread=0, nerrors=1, basketnumber=4
Error in TDCacheFile::ReadBuffer: error reading all requested bytes from file dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root, got 10663 of 11039
Error in TBranchElement::GetBasket: File: dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root at byte:0, branch:muons.calEnergyEmS9, entry:5, badread=0, nerrors=1, basketnumber=5
Error in TDCacheFile::ReadBuffer: error reading all requested bytes from file dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root, got 8304 of 13552
Error in TBranchElement::GetBasket: File: dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root at byte:0, branch:iterativeCone5GenJets.JetPart, entry:17, badread=0, nerrors=1, basketnumber=6
Error in TDCacheFile::ReadBuffer: error reading all requested bytes from file dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root, got 13742 of 22151
Error in TBranchElement::GetBasket: File: dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root at byte:0, branch:generalTracks.Part.v.fP.fX, entry:56, badread=0, nerrors=1, basketnumber=7
Error in TDCacheFile::ReadBuffer: error reading all requested bytes from file dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root, got 12147 of 12855
Error in TBranchElement::GetBasket: File: dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root at byte:0, branch:iterativeCone5GenJets.JetPart, entry:59, badread=0, nerrors=1, basketnumber=8
Error in TDCacheFile::ReadBuffer: error reading all requested bytes from file dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root, got 9747 of 13066
Error in TBranchElement::GetBasket: File: dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root at byte:0, branch:iterativeCone5GenJets.JetPart, entry:80, badread=0, nerrors=1, basketnumber=9
Error in TDCacheFile::ReadBuffer: error reading all requested bytes from file dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root, got 13826 of 21731
file probably overwritten: stopping reporting error messages
Error in TBranchElement::GetBasket: File: dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root at byte:0, branch:generalTracks.Part.v.fP.fX, entry:112, badread=0, nerrors=1, basketnumber=10
Error in TDCacheFile::ReadBuffer: error reading all requested bytes from file dcap://maite.iihe.ac.be/pnfs/iihe/cms/s … O_1_1.root, got 9137 of 10701
R__unzip: error in header
Error in TBasket::ReadBasketBuffers: fNbytes = -480613552, fKeylen = 29681, fObjlen = 50073527, noutot = 0, nout=0, nin=9, nbuf=0

*** Break *** segmentation violation
(no debugging symbols found)
Attaching to program: /proc/4427/exe, process 4427
[Thread debugging using libthread_db enabled]
[New Thread 0xf53b3aa0 (LWP 4427)]
0xffffe410 in __kernel_vsyscall ()
#1 0x003a6df3 in __waitpid_nocancel () from /lib/libc.so.6
#2 0x0034c06b in do_system () from /lib/libc.so.6
#3 0xf78baa8d in TUnixSystem::Exec ()
from /jefmount_mnt/jefmount/cmss/slc5_ia32_gcc434/cms/cmssw/CMSSW_3_5_7/external/slc5_ia32_gcc434/lib/libCore.so
#4 0xf78bff2b in TUnixSystem::StackTrace ()
from /jefmount_mnt/jefmount/cmss/slc5_ia32_gcc434/cms/cmssw/CMSSW_3_5_7/external/slc5_ia32_gcc434/lib/libCore.so
#5 0xf78c0cfd in TUnixSystem::DispatchSignals ()
from /jefmount_mnt/jefmount/cmss/slc5_ia32_gcc434/cms/cmssw/CMSSW_3_5_7/external/slc5_ia32_gcc434/lib/libCore.so
#6 0xf78c0dfd in SigHandler ()
from /jefmount_mnt/jefmount/cmss/slc5_ia32_gcc434/cms/cmssw/CMSSW_3_5_7/external/slc5_ia32_gcc434/lib/libCore.so
#7 0xf78b7702 in sighandler ()
from /jefmount_mnt/jefmount/cmss/slc5_ia32_gcc434/cms/cmssw/CMSSW_3_5_7/external/slc5_ia32_gcc434/lib/libCore.so
#8
#9 0xf6d8d119 in TBufferFile::ReadInt ()
from /jefmount_mnt/jefmount/cmss/slc5_ia32_gcc434/cms/cmssw/CMSSW_3_5_7/external/slc5_ia32_gcc434/lib/libRIO.so
#10 0xf6d8b83b in TBufferFile::ReadArray ()
from /jefmount_mnt/jefmount/cmss/slc5_ia32_gcc434/cms/cmssw/CMSSW_3_5_7/external/slc5_ia32_gcc434/lib/libRIO.so
#11 0xf6a816c1 in TBasket::ReadBasketBuffers ()
from /jefmount_mnt/jefmount/cmss/slc5_ia32_gcc434/cms/cmssw/CMSSW_3_5_7/external/slc5_ia32_gcc434/lib/libTree.so
#12 0xf6a846d2 in TBranch::GetBasket ()
from /jefmount_mnt/jefmount/cmss/slc5_ia32_gcc434/cms/cmssw/CMSSW_3_5_7/external/slc5_ia32_gcc434/lib/libTree.so
#13 0xf6a84ee5 in TBranch::GetEntry ()
from /jefmount_mnt/jefmount/cmss/slc5_ia32_gcc434/cms/cmssw/CMSSW_3_5_7/external/slc5_ia32_gcc434/lib/libTree.so
#14 0xf6a938a2 in TBranchElement::GetEntry ()
from /jefmount_mnt/jefmount/cmss/slc5_ia32_gcc434/cms/cmssw/CMSSW_3_5_7/external/slc5_ia32_gcc434/lib/libTree.so
#15 0xf6a93825 in TBranchElement::GetEntry ()
from /jefmount_mnt/jefmount/cmss/slc5_ia32_gcc434/cms/cmssw/CMSSW_3_5_7/external/slc5_ia32_gcc434/lib/libTree.so
#16 0xf6ad193c in TTree::GetEntry ()
from /jefmount_mnt/jefmount/cmss/slc5_ia32_gcc434/cms/cmssw/CMSSW_3_5_7/external/slc5_ia32_gcc434/lib/libTree.so
#17 0xf7f7c7ee in main () from ./analysis7tev_C.so
#18 0x0032be8c in __libc_start_main () from /lib/libc.so.6
#19 0x080483f1 in _start ()
The program is running. Quit anyway (and detach it)? (y or n) [answered Y; input not from terminal]

2

Does anybody have an idea on the subject? or a pointer to where I can start looking?

Thanks,

Olivier.

3

Hi Olivier,

can you tell me the dcap version and root versions?

Regards,
Tigran.

4

Hi Tigran,

thanks for helping out. here are the answers:
ROOT 5.22/00d (branches/v5-22-00-patches@29532, Jan 27 2010, 15:18:00 on linux)

rpm -qa | grep dcap
dcache-dcap-1.8.0-4

Kind regards,

O.

5

Please check that your root version is linked with correct dcap library.
nm $ROOTSYS/lib/libDCache.so | grep dc_readv2
In addition I will suggest to update our dcap library to the latest one:

dcache.org/downloads/dcap/

Regards,
Tigran.

6

I now have 2 questions :slight_smile:

  1. this is the result of your command:
    nm $ROOTSYS/lib/libDCache.so | grep dc_readv2
    U dc_readv2

but I have no idea what this implies.

  1. I have indeed been meaning to upgrade our full dcache, but that will have to wait for some time. Bust can I upgrade dcap without dcache? Stated otherwise: are the versions from dcap linked to thoase of dcache?

Regards,

O.

7

all dcap clients can talk to any version of dcache as well as any dcache version will
work correctly with any dcap client.

In other words, you can update dcap client without updating dcache version.

Regards,
Tigran.

8

Hi Tigran,

I updated my dcap:

rpm -qa | grep dcap
dcap-2.47.2-0
libdcap-2.47.2-0

dccp indeed still works :slight_smile:

dccp -v
DiskCache Copy Program. LibDCAP version: 2.47.2-0

but the errors still remain. I still do not understand the meaning of this:
nm $ROOTSYS/lib/libDCache.so | grep dc_readv2
U dc_readv2

I guess it is the correct value, but then, I’m again clueless as to continue.
One remark though. the script can partially read the file as it read the correct number of events in the file (it is the same as reported when the file is on the local file system).

Kind regards,

Olivier.