Cron queue not working
You need to add items to your queue. You have created a queue, but haven't added anything to it, so nothing is being done.

$queue-&gt;createItem($item);


$item will get passed to the queue callback function (_import_all_jobs).

I would suggest modifying _import_all_jobs to import an individual job (_import_job). Then $item would be a job added to the queue and you let DrupalQueue do its thing.

This article may be helpful: Cron Queues: Processing large amounts of data in cron

And here is some relevant Drupal documentation: Queue operations