This seems to be an issue for many but I didn't see much in light for Linux systems.   I've done it all picked up the drivers from https://jdbc.postgresql.org/download.html placed these drives in the nifi-1.11.4/lib/ folder.    I've restarted Nifi, verified the database, verified the filepath, altered the path name with "file:///", altered the path to say just lib/postgresql-42.2.12.jar, attempted to use another database user. I know that the connection information is correct because I connected to the DataGrip UI. I'm completely stumped.  Database Connection URL               jdbc:postgresql://localhost:5432/forestdb Database Driver Class Name           org/postgresql/Driver.class Database Driver Location(s)             /home/fg/Documents/nifi-1.11.4-bin/nifi-1.11.4/lib/postgresql-42.2.12.jar Database User                                  admin Password                                          123 Max Wait Time                                   500 millis     16:03:08 CDT ERROR 01711097-9fd7-1476-e26e-a9bf77b2dff7 StandardControllerServiceNode[service=DBCPConnectionPool[id=01711097-9fd7-1476-e26e-a9bf77b2dff7], versionedComponentId=null, processGroup=StandardProcessGroup[identifier=6428af02-0171-1000-124e-9aeed8d62c82], active=true] Failed to invoke @OnEnabled method due to org.apache.nifi.reporting.InitializationException: Can't load Database Driver: Can't load Database Drive       ... View more

My goal is to pass the data coming in as a JSON to my script and update it to UNIX time. using python. but it is saying line 63 is being referenced before called, "json_data". This is at the session writer near the bottom Processors being used is Convert Record -Execute Script--. The message being passed looks like this: json_data =   {"Year":2018,"DOY":12,"Hour":20,"HGI_Lat_of_the_S/C":7.0,"IMF_B_scalar_nT":1.03,"SW_Plasma_Speed_KMs":441.0}   and should pop out like this   {"HGI_Lat_of_the_S/C": 7.0, "IMF_B_scalar_nT": 1.03, "SW_Plasma_Speed_KMs": 441.0, "Unix_time": 1542074400.0}   Error message:   ExecuteScript[id=01711026-9fd7-1476-8c67-e730c921e164] Failed to process session due to javax.script.ScriptException: UnboundLocalError: local variable 'json_data' referenced before assignment in <script> at line number 63: org.apache.nifi.processor.exception.ProcessException: javax.script.ScriptException: UnboundLocalError: local variable 'json_data' referenced before assignment in <script> at line number 63   Python code:   import json from datetime import datetime import java.io from org.apache.commons.io import IOUtils from java.nio.charset import StandardCharsets from org.apache.nifi.processor.io import StreamCallback class PyStreamCallback(StreamCallback): def __init__(self): self.year=[] self.day=[] self.hour=[] self.month=[] self.key1_year = 'Year' self.key4_month = 'month' self.key2_day = 'DOY' self.key3_hour = 'Hour' # Write bytes that are utf-8 encoded chine word. def process(self, inputStream, outputStream): text = IOUtils.toString(inputStream, StandardCharsets.UTF_8) #obj = json.loads(text) #json_data = json.dumps(text) json_data = json.loads(json_data) try: self.year.append(json_data[self.key1_year]) except KeyError: self.year.append(2000) try: self.month.append(json_data[self.key4_month]) except KeyError: self.month.append(11) try: self.day.append(json_data[self.key2_day]) except KeyError: self.day.append(11) try: self.hour.append(json_data[self.key3_hour]) except KeyError: self.hour.append(11) new = year+month+day+hour # Considering date is in mm/dd/yyyy format #converting the appendd list to strings instead of ints b=[str(x) for x in new] #joining all the data without adding b = '/'.join(b) #convert to unix dt_object2 = datetime.strptime(b, "%Y/%m/%d/%H") timestamp = datetime.timestamp(dt_object2) json_data.update({'Unix_time':timestamp}) #deleting unwanted data from the dict for func in [self.key1_year,self.key4_month,self.key2_day,self.key3_hour]: try: del json_data[func] except KeyError as e: pass outputStream.write(bytearray(json.dumps(json_data).encode('utf-8'))) flowFile = session.get() if (flowFile != None): flowFile = session.write(flowFile, PyStreamCallback()) session.transfer(flowFile, REL_SUCCESS)   ... View more

Is there something about configuring Nifi that needs to be done when setting up?   I ask because I've worked on a few different systems and the one I just set up seems to be having issues with Regex, prepend, and other items.  ... View more