Upgrading Apache Nifi to the latest version often brings improvements to memory usage and bug fixes. You should rarely need to upgrade Nifi once you are up and running since the Lingk API Plugin only impacts a small portion of the capabilities of Apache Nifi.Pre-requisites:Apache Nifi installed at C:\
ifi or C:\
ifi-1.x . This location will be referenced as directory in the rest of this guide. Windows Service setup through NSSMEstimated downtime: 30 minutesHere are the steps to do a safe upgrade of Apache Nifi on Windows.Download the latest version of NifiUnzip into a new directoryC:\
ifi-or Download the latest Nifi flow templateLog into the current running instanceSelect your API flowClick the button to "save" the templateGo to Templates under the right hamburger menuDownload the saved template XML file to the desktopEnsure any certificates are available Capture any keys/passphrases for the keystore or trust stores needed for the certificate.You may need to ask IT for these as they are hidden by Nifi after entering the values.Copy any variables that are set at the top-level Nifi processor to a text fileEnsure the listening ports for the APIs are not different than the default. Copy the port numbers if so.Shut down the running version of Nifi by turning the service off via NSSM (the downtime has started).Copy the extras folder from the directory to the .Copy the custom Nar files to the /lib folder.Config the rolling logging options per the Nifi Performance and Monitoring page.Update the NSSM service with the directory.Start the service. Capture the new username/password by searching for "Generated" in the app.log file (under logs).Open the browser and login to the new instance.Upload the template from step #2.  Start the controller servicesUpdate the SSL service as needed from step #3.If needed, connect to the database.Update the variables using values from step #4 and, optional, port values from step #5.Start all processors.Test the API from the recipe or Postman.No APIs, ports or configurations should have changed between the two Nifi instances.The old Nifi instance directory can stay for a while if you want to go back for some reason. Once you feel comfortable with the new instance, delete the old Nifi directory.