GenerateFcl

Introduction

This procedure is used to generate a set of fcl files, one for each job to be run in project. The fcl might drive a simulation project that starts with a generator, or a later stage of simulation starting with the art file output of an earlier stage, or a file concatenation project, or even an analysis project.

Preparation

A fcl file should be developed and verified with interactive jobs before it is prepared for a grid job. Several examples of simulation fcl files are under the JobConfig subdirectory of Offline. Using the fcl with the production system imposes one extra requirement: all output files of the job should satisfy the Mu2e naming conventions. The values of the owner, configuration, and sequencer fields used in the prepared fcl file are not important, because they will be overridden later. The values of data_tier, description, and file_format will be used as is and must be set correctly, please see file names for guidelines on how to use these fields. Use the "art" extension ("file format") for framework outputs (written by RootOutput modules) and "root" for TFileService (ntuple and histogram) file output files.

Setup

Setup the utilities

setup mu2e
source the appropriate Offline setup.sh file for your project
setup mu2etools

The above makes the generate_fcl command available in your path.

Generating fcl

There are two invocation modes that require mutually exclusive sets of parameters

• For jobs with EmptyEvent input source (events created by a generator) specify
  • --run-number that will be used for all the generated fcl files
  • --events-per-job
  • --njobs
• Jobs with RootInput source (art files) require
• --inputs a file containing a list of all input data full filespecs
• --merge-factor how many input files should be analyzed by a single job

The number of generated fcl files will be determined from the above inputs.

The following parameters are used to construct the names of fcl files produced by the generate_fcl invocation. Please see file names for guidelines on how to use these fields.

• --description the "description" field of fcl file names
• --dsconf the "configuration" field
In production, this field is often reduced to a date (mmdd format) and a version letter, for example "1231a", by convention. What these tags mean has to be recorded elsewhere.
• --dsowner the "owner" field. This parameter defaults to the user who executes generate_fcl, but can be overridden. For example, --dsowner=mu2e should be used to generate an official production dataset of fcl files.

The --old-seeds parameter can be used for incremental generation of fcl datasets. For example, one can generate a test batch of 1000 fcl files and run them through the grid. If the result is satisfactory, and one wants to increase the statistics to 10,000 jobs, care should be taken to guarantee the uniqueness of random seeds across all the 10,000 jobs. Each run of generate_fcl produces a text file that contains the values of all random seeds used so far for the current set of jobs. So when generate_fcl is used the second time to add 9,000 jobs to the dataset, one should use the file with 1000 seeds from the first run for the --old-seeds parameter to make sure those seeds are not re-used. (Also, --first-subrun should be adjusted so that subrun numbers do not repeat.) The second run will dump a list of 10,000 seeds, which can be used in a subsequent generation if a further increase in statistics is desired. For the initial run you can specify --old-seeds=/dev/null.

Run generate_fcl --help to see all the options.

Examples

Create a working dir. The data disk is a good place to work since we want fast response and some moderate space.

  mkdir -p /mu2e/data/users/`whoami`/fclds/my_project_name
  cd /mu2e/data/users/`whoami`/fclds
  mkdir 20161121-my_project_name
  cd 20161121-my_project_name

Example 1 - generator

A first stage simulation job with no input files.

Prepare a template file. Usually it can be a single line file with just an include directive, in our case

#include "JobConfig/cd3/pions/pions_g4s1.fcl"

but one can also add e.g. geometry file overrides, or even write a completely new fcl configuration and use it as a template. In this example we use template.fcl as the template file name. Note that the include directive should specify include file pathname relative to the Offline directory that you setup earlier. (More precisely, relative to a directory listed in the FHICL_FILE_PATH.) Absolute filenames do not work in fhicl #include.

Now generate the files:

generate_fcl --description=my-test-s1 \
             --dsconf=v0 \
             --run=2700 \
             --events=1000 \
             --njobs=5 \
    template.fcl

After the command completes, we will see something like

> ls
000  template.fcl  seeds.gandr.my-test-s1.v0.Td6j.txt
> ls 000
cnf.gandr.my-test-s1.v0.002700_00000000.fcl       cnf.gandr.my-test-s1.v0.002700_00000002.fcl.json
cnf.gandr.my-test-s1.v0.002700_00000000.fcl.json  cnf.gandr.my-test-s1.v0.002700_00000003.fcl
cnf.gandr.my-test-s1.v0.002700_00000001.fcl       cnf.gandr.my-test-s1.v0.002700_00000003.fcl.json
cnf.gandr.my-test-s1.v0.002700_00000001.fcl.json  cnf.gandr.my-test-s1.v0.002700_00000004.fcl
cnf.gandr.my-test-s1.v0.002700_00000002.fcl       cnf.gandr.my-test-s1.v0.002700_00000004.fcl.json

The generated fcl files and their corresponding json files are written into subdirectories 000, 001, etc, with up to 1000 fcl files per subdirectory. Random number seeds used for all the fcl files have been dumped into the "seeds" file.

Example 2 - mixing

A digitization+reconstruction job on a conversion electron file, with background mixing.

Prepare a template file. We want to use JobConfig/cd3/beam/dra_mix_baseline.fcl, but in many Offline releases this file is, strictly speaking, not a valid fcl because it references a variable bgHitFiles that is not defined. (A legacy of the mu2eart way of running grid jobs.) To fix that, we define the variable before including the "baseline" file. This example template.fcl also shows how to set names of output histogram files.

BEGIN_PROLOG
bgHitFiles: @nil
END_PROLOG
#include "JobConfig/cd3/beam/dra_mix_baseline.fcl"
services.TFileService.fileName: "nts.owner.my-ce-reco.ver.seq.root"

We also need a list of input files, and a list of background overlay files. We want to run 5 jobs with one input file per job, so we need to shorten the conversion list to have only 5 input files. We only need one background hits file per job, but there is no harm of listing more background overlay files than necessary, so we will use a complete detmix-cut dataset:

setup mu2efiletools
mu2eDatasetFileList sim.mu2e.cd3-beam-g4s4-detconversion.v566.art | head -n 5 > inputs.txt
mu2eDatasetFileList sim.mu2e.cd3-detmix-cut.v566b.art > backgrounds.txt

We are ready to generate the fcl dataset. Note the '@' symbol in the --aux parameter - it says that bgHitFiles should be devined in a PROLOG, as the included file expects instead of being appended at the end.

generate_fcl --desc=my-reco-test \
             --dsconf=v0 \
             --inputs=inputs.txt \
             --merge=1 \
             --aux=1:@bgHitFiles:backgrounds.txt \
template.fcl

Take a look:

> ls
000  backgrounds.txt  template.fcl  inputs.txt  seeds.gandr.my-reco-test.v0.CRdP.txt
> ls 000
cnf.gandr.my-reco-test.v0.004001_00000000.fcl       cnf.gandr.my-reco-test.v0.004001_00000002.fcl.json
cnf.gandr.my-reco-test.v0.004001_00000000.fcl.json  cnf.gandr.my-reco-test.v0.004001_00000003.fcl
cnf.gandr.my-reco-test.v0.004001_00000001.fcl       cnf.gandr.my-reco-test.v0.004001_00000003.fcl.json
cnf.gandr.my-reco-test.v0.004001_00000001.fcl.json  cnf.gandr.my-reco-test.v0.004001_00000004.fcl
cnf.gandr.my-reco-test.v0.004001_00000002.fcl       cnf.gandr.my-reco-test.v0.004001_00000004.fcl.json

Test fcl

It is highly recommended to test a newly generated fcl file by running a small interactive job. Following up on Example 1 above, one can do

mkdir test
cd test
/usr/bin/time mu2e -c `ls ../000/*.fcl | head -1`

to run a full size job, or add a -n 10 option to the mu2e command line to quickly make sure that there are no obvious problems with the configuration.