Question

A database connector is failing. The error in the dashboard is showing:

com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure\n\n
The last packet sent successfully to the server was 0 milliseconds ago.
The driver has not received any packets from the server.

Environment

All database connectors

Answer

Troubleshooting steps

1. Check if your Firewall settings have changed and may be now preventing Fivetran from accessing. 

2. Check if your database is blocking Fivetran's access via permission changes. 

Cause

The connector is unable to establish a connection with the source database. This can happen when the database's firewall settings have changed. 

In the Case of MySQL

The error visible on the dashboard is a secondary error to: 

ERROR 2013 (HY000): Lost connection to MySQL server at 'reading initial communication packet', system error: 0

This Online Forum post provides more info about this error.