Re: a problem with TTreeCache

Hi Simon,

See the similar report on the ROOT forum at <http://root.cern.ch/phpBB3/viewtopic.php?t=14082> for further update.

Cheers,
Philippe.

On 1/18/12 10:58 AM, Szymon Gadomski wrote:
> Dear ROOT Developers,
> While reading data from our DPM Storage Element, using the
> rfio protocol, we have seen errors that seem to come from
> TTreeCache. Here is a report.
>
> The error message is:
>
> Error in <TRFIOFile::TRFIOFile>: error doing rfio_read
> Error in <TBranch::GetBasket>: File:
> rfio:///dpm/unige.ch/home/atlas/atlaslocalgroupdisk/user/wbell/data11_7TeV/user.wbell.data11_7TeV.00191239.physics_Muons.merge.NTUP_TOPMU.f413_m1019_p694_p722_thin0001_0001.111112032448/user.wbell.005705._00037.output.root
> at byte:536958, branch:EF_e45_medium1, entry:459, badread=1, nerrors=1, basketnumber=1
> terminate called after throwing an instance of 'std::out_of_range'
> what(): vector::_M_range_check
> /var/spool/torque/mom_priv/jobs/1418590.grid07.unige.ch.SC: line 55: 6815 Aborted
>
> This happens when the Storage Element is busy. An 'error doing
> rfio_read' leads to 'std::out_of_range'. It looks like reading
> is not blocked when the process should be waiting for more data.
> Instead the process continues and crashes, printing errors due
> to corrupted data.
>
> In the user code we have the lines (m_tree is a TTree*):
>
> m_tree->SetCacheSize(104857600);
> TTreeCache::SetLearnEntries(1); // Stop learning after 1 entry is read.
> m_tree->AddBranchToCache(branchName,true);
>
> Removing all these lines makes the errors disappear.
> This is why we think there is a problem with the TTreeCache.
> We are using ROOT 5.30/05.
>
> Please let us know if any more information would be useful.
> Best regards,
> Szymon Gadomski
>
Received on Fri Feb 03 2012 - 18:45:27 CET