LEGEND L200 dataflow

Note: Still work in progress.

Implementation of an automatic data processing flow for L200 data, based on Snakemake.

Configuration

Data processing resources are configured via a single site-dependent (and possibly user-dependent) configuration file, named "config.json" in the following. You may choose an arbitrary name, though.

Use the included templates/config.json as a template and adjust the data base paths as necessary.

When running Snakemake, the path to the config file must be provided via --configfile=path/to/configfile.json. For example, run

snakemake -j`nproc` --configfile=config.json file_to_generate

Snakefile

Snakemake is controlled using the Snakefile which specifies the rules to generate each file. The path to the Snakefile must be provided via --snakefile path/to/Snakefile.

Key-Lists

Data generation is based on key-lists, which are flat text files (extension ".keylist") containing one entry of the form {experiment}-{period}-{run}-{datatype}-{timestamp} per line.

Key-lists can be auto-generated based on the available DAQ files using Snakemake targets of the form

• all-{experiment}.keylist
• all-{experiment}-{period}.keylist
• all-{experiment}-{period}-{run}.keylist
• all-{experiment}-{period}-{run}-{datatype}.keylist

which will generate the list of available file keys for all l200 files, resp. a specific period, or a specific period and run, etc.

For example:

snakemake -j4 --configfile=config.json all-l200-myper.keylist

will generate a key-list with all files regarding period myper.

File-Lists

File-lists are flat files listing output files that should be generated, with one file per line. A file-list will typically be generated for a given data tier from a key-list, using the Snakemake targets of the form {label}-{tier}.filelist (generated from {label}.keylist).

For file lists based on auto-generated key-lists like all-{experiment}-{period}-{tier}.filelist, the corresponding key-list (all-{experiment}-{period}.keylist in this case) will be created automatically, if it doesn't exist.

Example:

snakemake -j4 --configfile=config.json all-mydet-mymeas-tier2.filelist

File-lists may of course also be derived from custom keylists, generated manually or by other means, e.g. my-dataset-raw.filelist will be generated from my-dataset.keylist.

Main output generation

Usually, the main output will be determined by a file-list, resp. a key-list and data tier. The special output target {label}-{tier}.gen is used to generate all files listed in {label}-{tier}.filelist. After the files are created, the empty file {label}-{tier}.filelist will be created to mark the successful data production.

Snakemake targets like all-{experiment}-{period}-{tier}.gen may be used to automatically generate key-lists and file-lists (if not already present) and produce all possible output for the given data tier, based on available tier0 files which match the target.

Example:

snakemake -j`nproc` --configfile=config.json all-mydet-mymeas-tier2.gen

Targets like my-dataset-raw.gen (derived from a key-list my-dataset.keylist) are of course allowed as well.

Monitoring

Snakemake supports monitoring by connecting to a panoptes server.

Run (e.g.)

panoptes --port 5000

in the background to run a panoptes server instance, which comes with a GUI that can be accessed with a web-brower on the specified port.

Then use the Snakemake option --wms-monitor to instruct Snakemake to push progress information to the panoptes server:

snakemake --wms-monitor http://127.0.0.1:5000 [...]

Using software containers

This dataflow doesn't use Snakemake's internal Singularity support, but instead supports Singularity containers via venv environments for greater control.

To use this, the path to venv and the name of the environment must be set in "config.json".

This is only relevant then running Snakemake outside of the software container, e.g. then using a batch system (see below). If Snakemake and the whole workflow is run inside of a container instance, no container-related settings in "config.json" are required.

Running on a batch system

A template configuration to run the dataflow on an SGE batch system is included in templates/snakemake-config. Copy the configuration into "$HOME/.config/snakemake" and adjust as necessary (especially batch-queue selection, number of jobs, etc.).

You should then be able to run data production on the batch system via (e.g.):

snakemake --profile cluster-sge --jobs 20 --configfile=config.json all-l200-myper-dsp.gen