sPHENIX discussion of software

[pinkenburg <pinkenburg AT bnl.gov>]

Hi Jin,

(I just send this to the list since this is a real issue with the 
embedding for everyone)

after seeing what size 10 events produce I started just a few jobs 
yesterday evening. The output size just blows the bank (450 events so 
far with a 60GB output file) and - probably because of the i/o - is 
glacially slow (for G4 these are single particle sims, the 5000 events 
should have been done by now). The macro should contain the stripping of 
the truth info:

/gpfs02/phenix/prod/sPHENIX/preCDR/pro.1-beta.5/embedding/emcstudies/pidstudies/spacal2d/G4Setup.C

The next step would be to not save the absorber hits but then we loose 
all information about the energy in the absorber. Basically we need a 
module which analyzes them and writes some summary (one G4Hit with all 
energy?). We should also just remove all the saving of the forward stuff 
(steel doors, black holes). We should go over the original hijing files, 
since they are the vast majority of what is in the embedding output we 
can see where we get the biggest savings.

But in the end the whole approach we took is a dead end - we just 
multiply the size of the hijing input. We can either come up with a way 
to synchronize this so we read the original hijing files to get the 
hijing hits instead of saving them or we start to write out cells or 
towers which would reduce the output to a manageable size.

Chris

P.S. so far we are using 230TB of space on a filesystem which is meant 
as buffer for the production. This puts us where this becomes an issue 
for the production we want to start. What saves us is that the working 
groups are not using the space they have requested. There are still 
50000 jobs in the queue. We have to do something.

--
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Christopher H. Pinkenburg       ;    pinkenburg AT bnl.gov
                                ;    http://www.phenix.bnl.gov/~pinkenbu

Brookhaven National Laboratory  ;    phone: (631) 344-5692
Physics Department Bldg 510 C   ;    fax:   (631) 344-3253
Upton, NY 11973-5000

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