In the previous exercise we saw that the two tasks were running simultaneously.
We would like now to make sure that t2 only runs once t1 is complete.
For this we have to define a trigger
For instance, the second task might need data created by the first task.
If the condition is correct, the task is started, otherwise the task
Triggers can be between tasks, or between families, or a mixture.
Remember the two rules:
- A family is complete when all its tasks are complete.
- A task will be started if its triggers and the triggers of all is parent families evaluate to true.
expressions can be built (and keep in mind that the triggers of the
parent nodes are also implicit triggers).
Sometimes triggers are also used to prevent too many jobs from running
Nodes can be addressed in trigger expressions using full names: /test/f1/t1 refers to the
In some contexts, ecFlow will accept relative names, such as ../t1.
trigger /test/f1/t1 == complete
Triggers can be very complex, and ecFlow supports all kinds of conditions
(not, and, or, ...), in addition they can also reference Node attributes like
Text
#
...
Definition of the suite test.
suite test
edit ECF_INCLUDE "$HOME/course" # replace '$HOME' with the path to your home directory
edit ECF_HOME "$HOME/course"
family f1
edit SLEEP 20
task t1
task t2
trigger t1 eq complete
endfamily
...
endsuite
Python
#!/usr/bin/env python2.
...
7
...
import os
import ecflow
def create_family_f1():
...
f1
...
=
...
ecflow.Family("f1")
...
f1.add_variable("SLEEP", 20)
f1.add_task("t1")
f1.add_task("t2").add_trigger("t1 eq complete")
...
return f1
...
print
...
"
...
Creating suite definition
...
"
...
defs
...
=
...
ecflow.Defs()
suite = defs.add_suite("test")
suite.add_variable("ECF_INCLUDE", os.getenv("HOME") + "/course")
suite.add_variable("ECF_HOME", os.getenv("HOME") + "/course")
suite.add_family( create_family_f1() )
print defs
print "Checking job creation: .ecf -
...
> .job0
...
"
...
print defs.check_job_creation()
print "Checking trigger expressions
...
"
print defs.check()
print "Saving definition to file
...
'test.def
...
'"
defs.save_as_defs("test.def")
What to do:
- Edit the suite definition file to add the trigger.
- Replace the suite.
- Observe the tasks in ecflowview.
- See the triggers by selecting t1 or t2 and clicking on the icon.
- See the trigger relation by clicking on the arrow.
- See the triggers in the tree, using the Show drop down menu.
- Search any reference to t1 by using the icon