18 Feb 2017
We have a cron task that takes around 3-4 minutes to finish. I was worried a bit that, if my cron schedule is too frequent, two jobs might run concurrently. That might create inconsistent records in our database.
But I just tried clicking on 'Run now' on the cron job page (https://pantheon.corp.google.com/appengine/taskqueues?project=<your-project-id>&tab=CRON).
It turns out that the jobs are not started concurrently. That's great news.