Add a cron

The ecFlow server records all commands sent to it, in a log file (<host>.<port>.ecf.log) This log file will grow over time to a considerable size. In this exercise, we will create a task, whose job is to periodically back up and clear this log file. This will be done with cron attribute introduced in the previous page. A cron will run indefinitely. i.e. once it has completed it will automatically re-queue itself.

For more examples of adding a cron see the Adding Time Dependencies and Python API.

Ecf Script

We will create a new script, clear_log.ecf.

Listing 39 $HOME/course/test/house_keeping/clear_log.ecf

%include <head.h>

# copy the log file to the ECF_HOME/log directory
cp %ECF_LOG% %ECF_HOME%/log/.

# clear the log file
ecflow_client  --log=clear

%include <tail.h>

Text

For brevity, the previous families have been omitted.

# 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 house_keeping
        task clear_log
        cron -w 0 22:30  # run every Sunday at 10:30pm
    endfamily
endsuite

Python

For brevity, the previous families have been omitted.

Listing 40 $HOME/course/test.py

import os
from ecflow import (
    Defs,
    Suite,
    Family,
    Task,
    Edit,
    Trigger,
    Complete,
    Event,
    Meter,
    Cron,
)


def create_family_house_keeping():
    return Family("house_keeping", Task("clear_log", Cron("22:30", days_of_week=[0])))


print("Creating suite definition")
home = os.path.join(os.getenv("HOME"), "course")
defs = Defs(
    Suite("test", Edit(ECF_INCLUDE=home, ECF_HOME=home), create_family_house_keeping())
)
print(defs)

print("Checking job creation: .ecf -> .job0")
print(defs.check_job_creation())

print("Checking trigger expressions")
errors = defs.check()
assert len(errors) == 0, errors

print("Saving definition to file 'test.def'")
defs.save_as_defs("test.def")

What to do:

Make the changes to the suite definition file
Create all the necessary ecf scripts by copying the one from /test/f1/t7
Replace the suite.

Python: python3 test.py ; python3 client.py

Text: ecflow_client --suspend=/test ; ecflow_client --replace=/test test.def
ecflow_ui has a special window to explain why a task is queued. Select a queued task and click on the ‘Why tab’
Manually run the task. Examine the log file on disk.