[KAFKA-3352] Avoid DNS reverse lookups

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.10.0.0
• Assignee: Ismael Juma
• Reporter: Ismael Juma
• Created: 08/Mar/16 21:46
• Updated: 19/Jul/18 11:28
• Resolved: 09/Mar/16 22:20

Description

We use `InetSocketAddress.getHostName` in `Cluster.bootstrap` and `SocketServer` This call can cause a reverse DNS look-up if an IP address is used in the configuration. `getHostString` avoids the reverse DNS look-up.

`InetAddress.getHostName` has the same issue and it's used in `SaslChannelBuilder`, `SslChannelBuilder` and `ZookeeperConsumerConnector`. I am not changing these because the the former two actually require the FQDN while the latter is on its way to deprecation.