cms_opendata

Install the Docker container from the official page of Docker https://docs.docker.com/engine/install

Installing in Ubuntu 20.04

1. Set up Docker's apt repository.

sudo apt-get update
sudo apt-get install ca-certificates curl
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc

# Add the repository to Apt sources:
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
sudo apt-get update

2. Install the Docker packages.

sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

3. Verify that the Docker Engine installation is successful by running the hello-world image.

sudo docker run hello-world

Using Docker with the CMS Open data

mkdir cms_opendata_work
chmod -R 777 cms_opendata_work

Use the link https://opendata.cern.ch/docs/cms-guide-docker for the available CMSSW container images

docker run -it --name my_opendata --net=host --env="DISPLAY" -v $HOME/.Xauthority:/home/cmsusr/.Xauthority:rw  -v ${HOME}/cms_opendata_work:/code cmsopendata/cmssw_7_6_7-slc6_amd64_gcc493 /bin/bash

docker start -i my_opendata

A demo for testing and validation

mkdir Demo
cd Demo
mkedanlzr DemoAnalyzer
scram b

make these changes to the confFile_cfg.py in the Demo/DemoAnalyzer/python directory:

1. Replace "file:myfile.root" with "root://eospublic.cern.ch//eos/opendata/cms/Run2015D/SingleElectron/MINIAOD/08Jun2016-v1/10000/001A703B-B52E-E611-BA13-0025905A60B6.root"
2. change -1 to 10 in process.maxEvents = cms.untracked.PSet( input = cms.untracked.int32(-1)).

Run the cms executable

cmsRun DemoAnalyzer/python/ConfFile_cfg.py

CMS NanoAOD Open Data

There is no need to use the CMS virtual machine or docker container to analyze the NanoAOD data but simply use C++ or Python script to analyze the ROOT file because the data is stored in ROOT TTree

Downloading the data on local machine

1. Install cern opendata-client using PyPI or Docker

   pip install --user cernopendata-client
   

2. The data files are available at https://opendata.cern.ch. We can listing the data files using record id (recid) or by digital object identifier (doi) number.

   cernopendata-client get-file-locations --doi 10.7483/OPENDATA.CMS.TTK7.008J
   cernopendata-client get-file-locations --recid 1
   

3. Downloading data files using doi

   cernopendata-client download-files --doi 10.7483/OPENDATA.CMS.TTK7.008J
   

4. To download data files use

   cernopendata-client download-files --recid 5500 --filter-name file1.root, file2.root, ...
   

5. Use the link "https://opendata.cern.ch/record/1059" to find the luminosity of the given file.