Adding 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. This section will create a task, whose job is to periodically back up and clear this log file.

This can be done with a cron attribute introduced previously. A cron will run indefinitely i.e. once it has completed it will automatically requeue itself.

More examples of how to add a cron, using the Python API, can be found at Adding Time Dependencies.

Task Script

Create a new task script named clear_log.ecf.

Listing 43 $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>

Update Suite Definition

Create a new family named house_keeping and add the task clear_log to it, that will run every Sunday at 10:30pm.

suite test
    edit ECF_INCLUDE "{{HOME}}/course" # replace '{{HOME}}' appropriately
    edit ECF_HOME    "$HOME/course"

    [... previous families omitted for brevity ..]

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

Listing 44 $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:

Update the suite definition to include the new family and task.
Create the new task script clear_log.ecf in the appropriate directory.

Replace the suite, using:

ecflow_client --suspend /test
ecflow_client --replace /test test.def

python3 test.py
python3 client.py

Use ecflow_ui to inspect why a task is queued, by selecting a queued task and clicking on the Why tab.
Manually run the task, and examine the log file on disk.