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.


The cylc installation on accessdev is setup to use a wrapper script raijin:~access/bin/cylc. This loads the module for the appropriate matching version so it's not necessary to load any rose/cylc modules in either your raijin shell environment or your suite.

With cylc 6 PBS directives can be specified on separate lines, so a sample suite.rc for raijin might include something like

            host =
        [[[job submission]]]
            method = pbs
            -l walltime=1:00
            -l ncpus=1
            -l mem=500mb

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

See CylcSix for information on the differences between cylc versions 5 and 6 and how to upgrade to the new version.

Last modified 6 years ago Last modified on Jul 6, 2015 10:29:00 AM