I have the following code example, which produces me tons of errors: Error in <TCollectionLessSTLReader::GetCP()>: Read error in TBranchProxy
They begin to pop up at some random event in the middle…
Hi,
there might be some issue with these particular files, can you share one that reproduces the issue? @pcanal do you have any idea what might cause that error?
I discover that it runs smoother with less threads… e.g. ROOT.EnableImplicitMT(5) gives an error around 2 mil event ROOT.EnableImplicitMT(4) still gives an error but around 4 mil event… ROOT.EnableImplicitMT(3) still gives an error but around 8 mil event… ROOT.EnableImplicitMT(2) still gives an error but around 9 mil event… # ROOT.EnableImplicitMT() makes it to the end
and it feels like time complexity is increasing with event number…
Could it be something to do with file access by different threads?
When I try to create TTrees with RDataFrame and add them as friends to the chain I encounter:
Error in <AddFriend>: Tree 'test1' has the kEntriesReshuffled bit set, and cannot be used as friend nor can be added as a friend unless the main tree has a TTreeIndex on the friend tree 'test2'. You can also unset the bit manually if you know what you are doing.
Maybe the reason code above fails, because files are quite large by itself… 34-47 GB… While I tried for an example only 3 GB files at max, at the moment… Maybe I am missing something, maybe I don’t… But I think this one is quite hard to catch…
Is there any way I can check what root does internally, while executing my code? Maybe this would help to track it
You can try setting ROOT.gDebug to a high-enough value but this is a problem in TTree/TTreeReader internals, we need either a genius insight by @pcanal or a way to reproduce and investigate on our side. Are the files private? If yes, could you maybe be allowed to duplicate just 1% of that data N times such that the dataset size is equal to the original (but the physics content is all redundant), so that the data can then be shared with us? (or maybe the data could simply be shared with me privately under the agreement that I don’t discover any new physics with it? )