Error in <TBranchElement::GetBasket>:

ROOT
1

Hi

Using atlas software (which uses root 5.10), we produce some ntuples. Most of them are ok but ~ 30 % have this error

(py script counting the number of events in the ntuple)
Warning in TClass::TClass: no dictionary for class AttributeListLayout is available
Warning in TClass::TClass: no dictionary for class pair<string,string> is available
SysError in TFile::Seek: cannot seek to position 4653867682515386368 in file AANnew._00001.root, retpos=-1 (Invalid argument)
Error in TFile::ReadBuffer: error reading all requested bytes from file AANnew._00001.root, got 0 of 3328120
Error in TBranchElement::GetBasket: File: AANnew._00001.root at byte:0, branch:MC_E, entry:202, badread=0
249 events

if we redo the job, it fixes sometimes the problem but not always. Is there something we can check ?

Thanks

Karim

2

Hi,

This sounds like a memory overwrite and/or a problem with disk. For the former you should use a memory debugging tool like valgrind to try to pin point the cause.

Cheers,
Philippe.

3

arghhh the job is not really reproducible … i dont have this problem when I run valgrind

I have compiled the head version of ROOT and this problem has disappeared :slight_smile: (at least when I count the events in the ntuple, dont know yet in the analysis code)

Karim