Improve task manager time handling

[dverdin]

Expected Behavior

In task manager, it would be cool to be able to : 1- define the interval between tasks execution in a user friendly formalism, such as "1d" instead of "86264", 2- execute some tasks at fixed time instead of fixed interval. For example: "everyday at 6PM".

Current Behavior

Currently, we can only define the interval beween two executions in seconds. And the first execution date defines the next one and the next and so on.

Possible Solution

• Enable a small parser to discriminate a simple number, that would indicate a number of seconds, from a more elaborate form.
• Compute the next execution date base on what is parsed.

Context

It would be nice for users to have a simpler formalism. The fixed time excution would be nice for people having fixed time database maintenance, to make sure synchronizations don't happen during it.

[ikedas]

On 2, we would use the other measures like cron (and we would be happy leaving from duty to maintain code for task management!).

However, it also might cause problem, e.g. when a hourly task didn’t finish in one hour.

[dverdin]

I'm not sure about cron. The problems I foresee are:

• the large number of tasks to handle. If you have 523 lists in 10 different vhosts, some querying a data source, some querying another, the resulting crontab will be very hard to handle,
• the articulation with some native Sympa mechanisms, such as lists families. How should the crontab be updated?
• the configuration scattering. You will have native task management for some lists, and crontab for other. It is disturbing for admins.

On the opposite, making fixed time tasks does just require to change the way we compute the epoch time in the task name that will determine when is the task executed.

[ikedas]

I don’t concider about method to add tasks to crontab. I think it may be solved relatively easily.

I think the problem with fixed execution time looks not so easy to solve.