Revert "Don't cache Zookeeper DNS"
Revert "Don't cache Zookeeper DNS"

mahak/vitess,tinyspeck/vitess,vitessio/vitess,tinyspeck/vitess,tinyspeck/vitess,vitessio/vitess,vitessio/vitess,tinyspeck/vitess,vitessio/vitess,mahak/vitess,tinyspeck/vitess,mahak/vitess,vitessio/vitess,mahak/vitess,tinyspeck/vitess,mahak/vitess,vitessio/vitess,mahak/vitess,mahak/vitess,vitessio/vitess,vitessio/vitess,tinyspeck/vitess,mahak/vitess