More detailed would be needed before I would know if I can offer any advice here.
Can you share: 1. PutDatabaseRecord processor configuration 2. Assuming you are using the CSVReader, please share its configuration 3. DBCPConnectionPool configuration 4. Complete Exception including any stack trace if exist form nifi-app.log. 5. Any data manipulations made between your GetFile and PutDatabaseRecord processors? 6. Sample input file would also be very helpful.