So  java.net.BindException: Cannot assign requested address is an error occurred while attempting to bind a socket to provided hostname and port. Typically, the port is in use, or the requested hostname could not be assigned, Are you sure port is free and no issues with the hostname you are using ?     ... View more

Details you can only get through UI or API , considering web endpoint is reachable, Seems in this case NiFi service is up but UI is not available or NiFi service is completely down , can be confirm by checking its process status. So you need find way to bring back the NIFI service along with UI in minimalistic load by stopping all flows by setting nifi.flowcontroller.autoResumeState to false and start the service, by doing this nifi will start with all the queued data but it will not do any processing, this can give you the UI but since you have said that are too much data so startup will take time.    If you found this response assisted with your issue, please take a moment to login and click on "Accept as Solution" below this post. Thank you, Chandan  ... View more

The error says the Connection pool is not able to find configured driver classpath name into provided database client-jar driver. Please check and make sure configured driver classpath name is present on the provided jar file.      ... View more