I've build index on solr 1.4 some time ago (about 18milions documents, about 8GB). I need new features from newer version of solr, so i decided to upgrade solr version from 1.4 to 3.5.
* I created new solr master on new physical machine * then I created new index using the same schema as in earlier version * then I indexed some slave, and start sending the same requests as earlier but to newer version of solr (3.5, but the same situation is on solr 3.4). The CPU went from 200% to 1200% and load went from 3 to 15. Avarage QTime went from 15ms to 180ms and median went from 1ms to 150ms I didn't change any parameters in solrconfig and schema. I don't have any idea what's going on. Did anybody notice same problem during change of solr version.
