SQL error when generating reports

Products

• Network Flow Analysis

Issue/Introduction

Reports showing below error when trying to generate

An error occurred!
Control(30002): Stacked Protocol Trend - In

A Unable to connect to any of the specified MySQL hosts. error was returned: at MySql.Data.MySqlClient.NativeDriver.Open() 

<Please see attached file for image>

Environment

NFA 9.3.8 
1 Console server on windows 2012 R2
1 Harvester on Linux
 

Cause

The problem was that the MySQL instance which is supposed to run on port 3307 was down. 

Resolution

Found that there is a log file named NFACustomStorageEngine.log which was owned by root user. 
Changed the user for the log file to NFA user and then try to start the MySQL CSE
Successfully started NQMySQL service
 

Additional Information

Also verify whether NFA poller service is running