UpdateRequest up = new UpdateRequest();
up.setAction( ACTION.COMMIT, true, true );
up.deleteByQuery( "*:*" );
up.process( getSolrCore0() );
up.process( getSolrCore1() );
up.clear();
// Add something to each core
SolrInputDocument doc = new SolrInputDocument();
doc.setField( "id", "AAA" );
doc.setField( "core0", "yup" );