Sharded findAndModify will not implicitly create the database if it does not exist

Start a ShardingTest and run: t = db.find_and_modify4; t.drop();   // this is the best way to build auto-increment function getNextVal(counterName) { var ret = t.findAndModify({ query: {_id: counterName}, update: {$inc: {val: 1}}, upsert: true, 'new': true, }); return ret; }   assert.eq(getNextVal("a"), {_id: "a", val: 1});