When a particular build of an Athena project is deemed ready for production it will be installed as a numbered release onto the ATLAS production CVMFS server.
ATLAS software is numbered according to the following scheme:
A.B.X[.Y]
A refers to the release series, e.g., release series
23 is used for Run 3 simulation and data taking 2023. NB that the release series matching the data taking year is here coincidental, and does not represent a convention.
B is the release flavour and usually corresponds to a particular
branch in the git repository for which the code base needs to be
different. e.g., 24.0 is the release series for MC23 simulation, and 2023 Tier-0 reconstruction & Trigger, while 25.2 is the release series for analysis.
Principle release flavours are:
| Flavour | Purpose |
| 0 | Tier-0 reconstruction, trigger, and corresponding simulation production |
| 2 | Derivations and Analysis |
| 6 | Event Generation |
The numbering scheme reflects historical releases where a larger number of different flavours were created. These have been consolidated since release 22.0 resulting in fewer projects, but the numbering for those that remain was kept the same to remain consistent.
Note that while there is a strong correspondence between release flavour and
Athena Project, it is not
absolute: e.g., AthDerivation and AthAnalysisBase would
both be built from flavour 2.
X is the major release number, monotonically increasing as code is developed
with bugs fixed and enhancements added.
Occasionally, Y will be used is a minor release number is required for developments
that branched from an older major release. e.g., 21.0.20.Y contained
any fixes required for MC16a, as releases 21.0.21 onwards contained
incompatible changes for MC16c. Most releases will not have a minor release number, and so A.B.X is fully sufficient.
To setup a production release the release number and project need to
be specified to asetup, e.g.,
asetup Athena,23.0.11
Release 24.0 is the current release for 2023 data taking, trigger, reprocessing, and MC production. It is a largely technical update with respect to 22.0, in order to provide a stable release through to the end of Run3, and provides full backwards-compatibility with outputs produced in that release. Switching between 22.0 and 24.0 should therefore require only minor adaptations if any.
Some key features are:
HEPMC3 and 64-bit event numbers, allowing for compatibility with future generator versions and larger event generation files to be produced, respectively.LCG version (LCG_102b) used for providing common libraries such as ROOT, allowing for future compatibility with Centos9s/AlmaLinux9/RHEL9 operating systems.AOD files produced in 24.0 can be used to produce derivations in 24.0-series releases (see the description in earlier section)
Release 22.0 was the release used for initial Run3 data taking, trigger, reprocessing, and MC production in 2022. It represents the culmination of a multi-year development program:
AOD files produced in 22.0 can be used to produce derivations in 23.0-series releases (up to 23.0.11)
Release 21.0 was the release for Run2 data taking, trigger, reprocessing, and MC production. It was the release series in which the current CMake-based build system, and gitlab-based code versioning, were first used.
NB future reprocessings of Run2 data, and associated MC productions, will be performed in 23.0 (or newer)
Releases prior to 21.0 used an entirely different release building and versioning infrastructure, and so are not covered here.
It is very easy to see which production releases are available, just by looking in CVMFS, e.g.,
$ ls /cvmfs/atlas.cern.ch/repo/sw/software/23.0/Athena
23.0.0 23.0.1 23.0.10 23.0.11 23.0.2 23.0.3 23.0.4 23.0.5 23.0.6 23.0.7 23.0.8 23.0.9
Where the release series and flavour are encoded in the highest
level directory, then the project, then the release number
(/cvmfs/atlas.cern.ch/repo/sw/software/A.B/PROJECT/RELEASE_NUMBER).
See the full asetup users guide for further options.
When a git tag is made for a production release the release coordinator will add some release notes to the tag, which you can read directly in GitLab (just navigate to the tag of interest) or through the git command line:
$ git show release/23.0.11
tag release/23.0.11
Tagger: Tadej Novak <tadej.novak@cern.ch>
Date: Wed Dec 7 13:27:09 2022 +0100
Release for derivations production and physics validation
commit 115629ba8b6a28ad16c5c09dff994a3c43339faf (tag: release/23.0.11, tag: release/22.6.26, tag: nightly/master/2022-12-07T0501, tag: nightly/master/2022-12-07T0313, tag: nightly/master/2022-12-07T0220, tag: nightly/master/2022-12-07T0001, tag: nightly/master/2022-12-06T2300, tag: nightly/master/2022-12-06T2101, tag: nightly/master/2022-12-06T2001, tag: nightly/master/2022-12-06T2000)
Merge: e823350ccd3 7681d5affec
...
If you need to find out which nightly build (see below)
corresponded to a particular release the ReleaseData file contains
useful information:
$ cat /cvmfs/atlas.cern.ch/repo/sw/software/23.0/Athena/23.0.11/InstallArea/x86_64-centos7-gcc11-opt/ReleaseData
[release_metadata]
release:23.0.11
nightly name:master
project name:Athena
nightly release:115629ba8b6
date:2022-12-06T2101
compiler:GNU-11.2.0
cuda:NVIDIA-11.7.99
cxxpath:/cvmfs/sft.cern.ch/lcg/releases/gcc/11.2.0-8a51a/x86_64-centos7/bin/g++
cudapath:/cvmfs/sft.cern.ch/lcg/releases/LCG_102b_ATLAS_6/cuda/11.7.1/x86_64-centos7-gcc11-opt/bin/nvcc
cmake:3.21.3
You can also search for references with the right tag or hash
in git using git describe:
$ git describe --tags --match 'release/*' nightly/22.0/2022-11-01T2101
release/22.0.101
$ git describe --tags --match 'nightly/*' release/22.0.101
nightly/22.0/2022-11-01T2101
$ git describe --tags --match 'nightly/*' 5a344df38c0
nightly/22.0/2022-11-01T2101
For all of the major branches in git, significant projects will always be built from the HEAD once a day. Colloquially these are known as nightly builds, but they might well happen during daylight hours.
Each ‘nightly’ is date stamped with the time at which the build started, in the form
YYYY-MM-DDTHHMM
e.g., 2017-04-26T0710 is the build which began on the 26th of April 2017 at
0710 (CERN localtime is used).
To make it easier to identify the precise set of code that was used
for a build, a git tag is created with the format nightly/BRANCH/YYYY-MM-DDTHHMM.
e.g., nightly/21.0/2017-04-26T0710.
The results of a nightly build (cmake configuration, build status and tests) is accessible via the NICOS nightly build page.
After the release has been built it will be installed on the nightlies CVMFS server for use.
These nightly builds are usually used as a base on which to develop code changes, so knowing how to set them up is important.
To setup a nightly release it is necessary to give the git branch, the project
and the timestamp to asetup, e.g.,
asetup 21.0,Athena,r2017-04-26T0710
Note that the datestamp should be prefixed by r (nightly release).
To make life easier asetup will accept an abbreviated form for
the datestamp:
| Form | Example | Comment |
rYYYY-MM-DD |
r2017-04-26 |
Default is to take the oldest time |
rMM-DD |
r04-26 |
No year means this year |
rDD (zero padded) |
r26 or r01 |
No month or year means this month, this year |
See the full asetup users guide for further details.
To see which nightly releases are installed it’s possible just to browse CVMFS:
atmic001:~$ ls /cvmfs/atlas-nightlies.cern.ch/repo/sw/main/
2017-03-08T2245 2017-03-21T2225 2017-04-03T2225 2017-04-17T2225
2017-03-09T2245 2017-03-22T2225 2017-04-04T2225 2017-04-18T2225
2017-03-10T2125 2017-03-23T2225 2017-04-05T2225 2017-04-19T2225
2017-03-11T2125 2017-03-24T2225 2017-04-07T2225 2017-04-20T2225
2017-03-12T2125 2017-03-25T2225 2017-04-08T2225 2017-04-21T2225
2017-03-13T2225 2017-03-26T2225 2017-04-09T2225 2017-04-22T2225
2017-03-14T2225 2017-03-27T2225 2017-04-10T2225 2017-04-23T2225
2017-03-15T2225 2017-03-28T2225 2017-04-11T2225 Geant4
2017-03-16T2225 2017-03-29T2225 2017-04-12T2225 atlas
2017-03-17T2225 2017-03-30T2225 2017-04-13T2225 dqm-common
2017-03-18T2225 2017-03-31T2225 2017-04-14T2225 latest-Athena
2017-03-19T2225 2017-04-01T2225 2017-04-15T2225 sw
2017-03-20T2225 2017-04-02T2225 2017-04-16T2225 tdaq-common
shows all the nightly builds available for the main branch (along
with some common software installation paths).
The project is installed within the datestamped directory, along with
supporting code (AthenaExternals, Gaudi and some installation logs).
For branches that may build more than one project the timestamps
for each project are probably different. The abbreviated asetup commands
will handle this smoothly, but do watch out for it if you are
directory browsing.
Each nightly build is also a release candidate for the next release number
for its project. i.e., if the last release of Tier-0 Athena was 21.0.26
then the nightly build will have a release candidate number of 21.0.27.
Release candidate numbers are stored in the version.txt file in the git
repository itself, e.g.,
this
is the release candidate number for MC16 and Tier-0 2017 data taking.
The release candidate number is buried in the CMVFS installation path, e.g.,
$ ls /cvmfs/atlas-nightlies.cern.ch/repo/sw/master/2017-04-23T2225/Athena
22.0.0
But as explained above it isn’t actually needed for setting up a nightly build.