Hostname Resolver Transformation
--------------------------------

It is often useful to re-key Kafka Source Records ``host`` field's value as an IP address into a resolved hostname for that IP address. The ``Hostname Resolver Transformation`` makes this easy. This transformation will perform a reverse DNS lookup to replace IP addresses with hostnames. For example, `127.0.0.1` will be replaced with `localhost` on most machines.

For example, use the transformation by including the following lines in your Connector config:

.. sourcecode:: properties

    transforms=myHostnameTransformName
    transforms.hostname.type=io.confluent.connect.syslog.HostnameResolverTransformation


Configuration Options
^^^^^^^^^^^^^^^^^^^^^

``field.name``
  The name of the field that contains the ip address of the remote host.

  * Type: string
  * Default: remoteAddress
  * Importance: medium

``dns.cache.stats.secs``
  The amount of time in seconds to dump the cache statistics for the DNS cache.

  * Type: int
  * Default: 300
  * Valid Values: [1,...]
  * Importance: low

``dns.cache.ttl.secs``
  The amount of time to cache a DNS entry for in seconds.

  * Type: int
  * Default: 300
  * Valid Values: [1,...]
  * Importance: low

``dns.query.timeout.secs``
  The amount of time in seconds before the query is timed out.

  * Type: int
  * Default: 15
  * Valid Values: [1,...]
  * Importance: low