It’s important to understand how service configurations are organized and stored in Ambari. Properties are grouped into Configuration Types (config types). A set of config types makes up the set of configurations for a service.

For example, the HDFS Service includes the following config types: hdfs-site, core-site, hdfs-log4j, hadoop-env, hadoop-policy. If you browse to Services > HDFS > Configs, the configuration properties for these config types are available for edit.

Versioning of configurations is performed at the service-level. Therefore, when you modify a configuration property in a service, Ambari will create a Service Config Version. The figure below shows V1 and V2 of a Service Configuration Version with a change to a property in Config Type A. After making the property change to Config Type A in V1, V2 is created.