Running Workflows on Gizmo

Hutch Data Core

Updated: June 1, 2021

Edit this Page via GitHub       Comment by Filing an Issue      Have Questions? Ask them here.

In order to execute a workflow using the gizmo SLURM cluster, follow these instructions in order to create a Nextflow config file. We recommend creating this file in a location that will be easy to reference for multiple projects, since it will not contain any information that is specific to any particular workflow or dataset.

In case you end up using multiple configuration files to coordinate execution on other systems (e.g. AWS), we recommend naming this configuration file something like nextflow.gizmo.config.

Work Directory

You need to select a work directory (or workDir), which will contain the temporary files produced during the course of workflow execution. This will not contain any of the final output files, and so it should ideally be located on the /fh/scratch/ filesystem to minimize unnecessary storage costs.

A typical workDir may be /fh/scratch/delete30/lastname_f/nextflow/work/.

Using Singularity

If you would like to use Singularity to run each individual step of a workflow inside a container (which also supports native execution of Docker containers), then you will need to specify a cacheDir location for those images to be stored.

Due to the large size of Singularity containers, we strongly recommend that you use the /fh/scratch/ filesystem for those image files.

A typical cacheDir may be /fh/scratch/delete30/lastname_f/nextflow/cache/.

Monitoring Workflow Progress with Tower

If you have set up an account in Nextflow Tower for monitoring workflow progress, you can specify that access token directly in the configuration file below. By placing that information in your configuration file, there is no need to additionally specify that information for each individual run.

If you do not have a Tower account set up, you can easily omit the entire tower {} section (all four lines including both brackets).

If you are interested in learning more about using Tower to monitor workflow progress, read our description.

Nextflow Configuration - Gizmo

Below is a template configuration file which can be used as your nextflow.gizmo.config. Please make sure to replace every placeholder value (e.g. <SINGULARITY_CACHE_DIR>), including the < and > characters.

singularity {
    enabled = true
    autoMounts = true
    cacheDir = '<SINGULARITY_CACHE_DIR>'
    runOptions = '--containall --no-home'

workDir = '<WORK_DIR>'
process.executor = 'slurm'
process.queue = 'campus-new'

tower {
  accessToken = '<TOWER_ACCESS_TOKEN>'
  enabled = true

If you have any problems using this configuration, please don’t hesitate to get in touch.

Updated: June 1, 2021

Edit this Page via GitHub       Comment by Filing an Issue      Have Questions? Ask them here.