Batching the C calls means that you all lookups are delayed by other lookups. This isn't very good for concurrency especially since it's reliant on network traf

Batching the C calls means that you all lookups are delayed by other lookups. This isn't very good for concurrency especially since it's reliant on network traffic. If you had a few lookups in the queue, you could end up having goroutines waiting a few seconds or for lots of lookups this could balloon out to minutes for a lookup. This is the trade off. In general most programs aren't making thousands of concurrent DNS lookups.