Long running tasks

[grogou]

Related to: #32
About running tasks.
The fatal error cases where PHP stops working and can't trigger Exceptions, for instance, allowed memory size exhausted, Maximum execution time of n seconds exceeded, - we can't do anything more, only can fix this issue on the next BTM cycle. For that, we created a new column in the tasks table - last_modified. After every task change, we change the task modification time. And on every BTM start, we get all running tasks if those exist, setting up to in_progress status, if it is a bulk task we set their bulk running arguments to failed status. We do this process if the double Cron interval time is less than the difference between the current time and the task modification time.

[arsendovlatyan]

@eriktad please log follow messing, when setting bulk arguments to failed:
Terminated execution of long-running bulk arguments: 1, 2, 3. Moved task to "In Progress"

[arsendovlatyan]

@eriktad

• according to my comment Long running tasks #32 (comment) , let's remove x2, just move task to in-progress if task is running longer than our cron job interval
• please make a separate commit to fix coding standards

[arsendovlatyan]

I don't like the way we have implemented migrations, but let's move to live and get back to this later, it's working anyway.

[arsendovlatyan]

It looks good for now, we can review migrations later.