"file has no keys"

ROOT
1

Hi All,

I face a problem when I run my analysis on PROOF. I post my problem here since I don’t think it’s PROOF-related. I try to produce a histogram with the following code

SlaveBegin()

 ProofFile = new TProofOutputFile("/tmp/mkoeff/testfile.root", "M");
 ProofFile->SetOutputFileName( "/tmp/mkoeff/testfile.root" );
 TDirectory *savedir = gDirectory;
 fout = ProofFile->OpenFile("RECREATE");
 savedir->cd();
 h_test = new TH1F("h_test","test histo",10,0,10);
 h_test->SetDirectory(fout);

Process()

Fill histogram

SlaveTerminate()

 TDirectory *savedir = gDirectory;
 savedir->cd();
 h_test->Write();
 ProofFile->Print();
 fOutput->Add( ProofFile );
 h_test->SetDirectory(0);
 gDirectory = savedir;

In the end when PROOF tries to merge the output from the different workers I get the error message(s):

Output file: /tmp/mkoeff/testfile.root workers still sending)
Error in TFile::ReadBuffer: error reading all requested bytes from file //tmp/mkoeff/testfile.root, got 248 of 300
Warning in TFile::Init: file //tmp/mkoeff/testfile.root has no keys
Output file: /tmp/mkoeff/testfile.root workers still sending)
Error in TFile::ReadBuffer: error reading all requested bytes from file //tmp/mkoeff/testfile.root, got 248 of 300
Warning in TFile::Init: file //tmp/mkoeff/testfile.root has no keys
etc.

testfile.root has no keys – what does this mean? I use ROOT v. 5.28.00

thanks

2

Have you tried to use the newest “v5-28-00-patches” branch instead of “v5-28-00”?
There are many bug fixes implemented, some of them are related to “merging files with TProofOutputFile”: http://root.cern.ch/drupal/content/root-version-v5-28-00-patch-release-notes