Feed import of 20,000 nodes. How to batch up 1000 at a time?
Which version of Drupal are you using? I haven't checked on Feeds for Drupal 8, but Feeds for Drupal 7 (unless it's changed in the last few years) has a hard-coded item limit of 50. If you're importing from a CSV, your node architecture is probably pretty simple. You could try the Feed Import module instead of Feeds, in my experience it's better suited for very large imports.