I missed in documentation: A KeyedProcessFunction is always a RichFunction. Therefore, access to the RuntimeContext is always available and setup and teardown methods can be implemented. See RichFunction.open(org.apache.flink.configuration.Configuration) and RichFunction.close().
https://ci.apache.org/projects/flink/flink-docs-master/api/java/org/apache/flink/streaming/api/functions/KeyedProcessFunction.html -- Sent from: http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/
