Below is the normal registry config of Dubbo2, if upgrading to Dubbo3 without adding any change, Dubbo3 will register both interface-level and app-level addresses to the registry by default.
<!-- Register both interface-level and app-level addresses by default --> <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
You can also change the default behaviour by specifying register-mode through different ways, like xml, properties or JVM args.
Take xml as an example:
<!-- Register app-level address only --> <dubbo:registry address="zookeeper://127.0.0.1:2181" register-mode="instance"/>
<!-- Register interface-level address only --> <dubbo:registry address="zookeeper://127.0.0.1:2181" register-mode="interface"/>
<!-- The default value, register both interface-level and app-level addresses --> <dubbo:registry address="zookeeper://127.0.0.1:2181" register-mode="all"/>
Further more, users can choose to set the default behaviour that could apply to all applications by using global config center. Check migration doc for more details.