Doing BIG imports and apache solr indexing using drush, batch api and cron

By big imports I mean creating millions of nodes and indexing them fo apache solr search. We needed to import 1 million records from file, 3 nodes for each record, one in each of our 3 languages. These nodes also had 3 taxonomy vocabularies, around 30 cck fields and we also needed to join another table containing a spatial coordinates for our geo field.