In this section we will quickly run through some of the more advanced features of Cylc’s scheduling logic.
So far we have written dependencies like
foo => bar. This is, in fact,
foo:succeed => bar. It means that the task
bar will run
foo has finished successfully. If
foo were to fail then
would not run. We will talk more about these task states
in the Runtime Section.
- When the task has started running.
- When the task finishes if it fails (produces non-zero return code).
- When the task has completed (either succeeded or failed).
It is also possible to create your own custom qualifiers to handle events within your code (custom outputs).
For more information see the Cylc User Guide.
In Cylc, cycle points are just labels. Tasks are triggered when their dependencies are met irrespective of the cycle they are in, but we can force cycles to wait for a particular time before running using clock triggers. This is necessary for certain operational and monitoring systems.
For example in the following suite the cycle
2000-01-01T12Z will wait
until 11:00 on the 1st of January 2000 before running:
[scheduling] initial cycle point = 2000-01-01T00Z [[special tasks]] clock-trigger = daily(-PT1H) [[dependencies]] [[[T12]]] graph = daily # "daily" will run, at the earliest, one hour # before midday.
See the Clock Triggered Tasks tutorial for more information.