Scheduled Tasks

Joomla's scheduled tasks allow an alternative method to the direct (ajax) cron. A task can execure one or more sub tasks: extracting, checking and reporting.

Using Joomla's scheduled tasks require the Lazy Scheduler or the Web Cron. These can be found in the global configurartion.

Resume tasks

Joomla's Scheduled tasks allows resuming (large) unfinished tasks.

With this option enabled, the extract and check task will be set to re-run on the next invocation.

This means that you can set the Execution Rule to a relative low frequency. Then invoke the scheduler more frequently. 

Checking for due extracts or checks is not very resource heavy, checking for due tasks is just even less.

Not that you will need visitors to your website for the Lazy Scheduler, alternatively set up a Web Cron or Command Line