Here is the repository for hackathon occured at INRA Toulouse on the 29 and 30 of november 2017. Ce git est écrit en FranGlais.
The purpose of this meeting was to test different workflow managers in an HPC environment. We didn't want to test Cloud and Docker functionalities.
- Estelle Ancelet (MIAT, Record),
- Philippe Bardou (GenPhySE, Sigenae),
- Floréal Cabanettes (MIAT, Bioinfo Genotoul),
- Cédric Cabau (GenPhySE, Sigenae),
- Sébastien Carrere (LIPM, Bioinfo),
- Ludovic Legrand (LIPM, Bioinfo),
- Sarah Maman (GenPhySE, Sigenae),
- Céline Noirot (MIAT, Bioinfo Genotoul),
- Maria Bernard (GABI, Sigenae)
- Review :
- Frameworks :
In directory to_start you will find data and some CWL workflow examples.
The purpose of the two days is to develop a workflow which perform :
- fastqc
- cutadapt
- STAR (Indexation if needed)
It would be great if the workflow/manager can handle a list of single fastq and paired fastq in a same workflow.
Required features of the workflow manager:
- Facility for a biologist / bio-analyst to understand errors
- Compatible HPC clusters (SGE, SLURM, ...)
- Easy development, handling and maintenance
- Few outbuildings
- A living community
- Generic input files (give file patterns)
- ... to be completed
Things to identify when testing managers:
- How does the manager behave if a child job is killed by the scheduler (overflow) / the user?
- Does the rerun work after killing the master job?
- During a rerun are the new parameters (put in the conf or in the command line) taken into account? For example memory options?
- Can we limit the total number of jobs used in parallel by the workflow?
- What is the space requirement during processing and after processing, are the files copied? symbolic links are made? if file are stored does it keep them zipped?
Read only Comparison sheet
If you want to add your tool or your feedback, please ask for access to [email protected].
After 2 days:
- we tried to test : Rabix, toil, pegasus without success regarding our infrastruture.
- 2 workflow managers stand out : NextFlow and Snakemake ( not a surprise ).
The caracteristics and the ease of coding are really similar. The main problem on nextflow is the memory needed by master job (50G of virtual mem not enougth!). On Snakemake it seems not to be as easy as on nextflow to use memory and cpu parameter in a rule/process.
Global comparison (here is a comparison of 06/2016)
| Atout/Inconv | Snakemake | Nextflow |
|---|---|---|
| + | Intègre directement plusieurs languages | Facilité de configurer cluster/process ds fichier a part |
| + | Sequana permettrait de palier fichier pairé | Gestion fichier pairé |
| + | Sequanix propose interface pour lancer les workflows | Accès immédiat aux variables mem/cpu ds process |
| -/+ | Modulable (1 workflow peut importer des rules provenant d'autres fichiers) | Non modulable (1 workflow = 1 fichier) |
| - | Ligne de cmd complexe pour soumission cluster | Mémoire utilisée par le job maître |
| - | Pas accès immédiat aux variables mem/cpu ds rules (mais faisable) | Mémoire utilisée par le job maître |
For more details on evaluated caracteristics check the Comparison sheet and the contents of directories in comparison.
Et CWL dans tout ca ?
L'implementation de CWL est vraiment bien pensée en particulier pour la parallelisation des tâches, merge des taches parallélisées, intégration de sous workflow. Mais il faut utiliser javascript pour faire le liant entre les steps ou gérer les conditions.
Le problème c'est que lorsque l'on a choisi un gestionnaire de workflow, on code directement ds le language / format attendu par le gestionnaire. Donc soit les gestionnaires se mettent à lire le CWL soit les bioinformaticiens devront coder dans deux languages ... j'en doute.
Il existe de nombreux workflows à disposition sur le net, donc en terme d'utilisation, je ne me contenterai pas d'utiliser un seul gestionnaire. Par contre pour coder, il faudra bien en choisir un, aujourd'hui, il n'y en a pas forcement un gestionnaire qui est mieux que l'autre.