We have a replica set with 2 nodes and a arbiter. We originally had the java driver configured using the hostnames and about 40% of the CPU time reported by JProfiler was getByName. I've now configured so that it's the IP address specified in the ServerAddress()... but it's still 20% via ServerAddress.updateInetAddress. Is it perhaps because the config of the replica set itself it still specified with hostnames not IP addresses?

I saw a mention of configuring a cache timeout for mapping, but I couldn't find it in the docs. Also, I saw that in the 3.x Java driver that caching is going to be removed completely. What am I missing? How can this take so much CPU?