wiki:Rose/Cylc User Guide

Cylc User Guide

Cylc is a job meta-scheduler developed by NIWA and the UK Met Office. It is designed to handle dependencies between runs and organise run resubmissions.

Please watch the youtube talk by Hilary Oliver:

Setting up

Cylc requires passwordless connection to the supercomputer in order to submit jobs.

Passwordless access to the supercomputer is only available using a passphrase-protected ssh-agent set up on your local computer. Instructions for setting this up are available in the SSH user guide.


A full user-guide for Cylc is available on the Cylc homepage. Only site-specific details are listed here.


Cylc jobs running on the supercomputer need to load the Cylc module before they run. NCI uses the PBS queuing system - note that Cylc only supports one instance of each flag, so for things like -l which have multiple uses these all have to be specified in a single line.

The following root definition is recommended for jobs running on raijin:

        initial scripting = """
            module use /g/data/access/modules
            module load cylc
            host =
        [[[job submission]]]
            method = pbs
            -l = "walltime=1:00,ncpus=1,vmem=500mb"

The directives section may be overridden as needed, but the other sections should not be set in your own job definitions.

See access/TotalviewCylc for notes on using the totalview debugger from within a suite.

Last modified 20 months ago Last modified on Apr 27, 2022 9:50:39 AM