Submitting a task to the LSF batch system

Hint

This example demonstrates how to submit a task to the LSF batch system. In it’s core, the task is the same as in Writing a basf2 analysis steering file. The key difference is the batch_system parameter that is set to "lsf" and additional settings that are used to steer the submission to LSF.

To define the batch system on which this task should run, the only change needed is to set the batch_system parameter to the desired batch system. The available options are:

• "local" for no batch submission

• "lsf" for LSF (see the LSF documentation)

• "htcondor" for HTCondor (see the HTCondor documentation)

• "slurm" for Slurm (see the Slurm documentation)

• "gbasf2" for the client to submit grid-based Belle II jobs (see the gbasf2 documentation)

In b2luigi there are some dedicated parameters for each supported batch system, see Batch Processing. For LSF, these parameters are:

• queue: the queue to submit the job to (default: "s")

• job_name: the name of the job to be displayed in the queue

import basf2 as b2
import modularAnalysis as ma
import variables.utils as vu
import vertex as vx


import b2luigi
from b2luigi.basf2_helper import Basf2PathTask
from Ex06_basf2_reconstruction import ReconstructionTask


@b2luigi.requires(ReconstructionTask)
class AnalysisTask(Basf2PathTask):
    treeFit = b2luigi.BoolParameter(default=True)
    result_dir = "results/AnalysisLSF"

    batch_system = "lsf"
    queue = "s"

    def output(self):
        yield self.add_to_output(f"ntuple_LSF_{self.identifier}.root")

    def create_path(self):
        main = b2.Path()

        particle = "mu" if str(self.event_type) == "mumu" else "e"

        ma.inputMdstList(
            environmentType="default", filelist=self.get_input_file_names("reconstruction.root"), path=main
        )

        # Fill final state particles
        ma.fillParticleList(decayString=f"{particle}+:fsp", cut="[abs(dr) < 2.0] and [abs(dz) < 4.0]", path=main)

        ma.fillParticleList(
            decayString="K+:fsp", cut="[abs(dr) < 2.0] and [abs(dz) < 4.0] and [kaonID > 0.2]", path=main
        )

        # reconstruct J/psi -> l+ --
        ma.reconstructDecay(
            decayString=f"J/psi:ll -> {particle}+:fsp {particle}-:fsp", cut="[2.92 < M < 3.22]", path=main
        )

        # reconstruct B+ -> J/psi K+
        ma.reconstructDecay(
            decayString="B+:jpsik -> J/psi:ll K+:fsp", cut="[Mbc > 5.24] and [abs(deltaE) < 0.2]", path=main
        )

        # Run truth matching
        ma.matchMCTruth(list_name="B+:jpsik", path=main)

        # Perform tree fit if requested
        if self.treeFit:
            vx.treeFit(list_name="B+:jpsik", conf_level=0.00, massConstraint=["J/psi"], path=main)

        # Define variables to save
        variables = ["Mbc", "deltaE", "chiProb", "isSignal"]
        variables += vu.create_aliases_for_selected(
            list_of_variables=["InvM", "M"], decay_string="B+:jpsik -> ^J/psi:ll K+:fsp", prefix="jpsi"
        )

        # Write variables into ntuple
        ma.variablesToNtuple(
            decayString="B+:jpsik",
            variables=variables,
            filename=self.get_output_file_name(f"ntuple_LSF_{self.identifier}.root"),
            treename="Bp",
            path=main,
            storeEventType=False,
        )

        return main

To execute tasks in batch mode, use the batch argument of the process method.

if __name__ == "__main__":
    b2luigi.process(AnalysisTask(n_events=10), batch=True)

Either pass batch=True as shown above or use the CLI option --batch when executing the script, e.g.:

python3 Ex09_basf2_analysis_LSF.py --batch