Hi @Veera Mundra
Error:
ERROR manager.SqlManager: Error executing statement: com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
MySQL specific CommunicationsException:Communications link failure, then it means that the DB isn't reachable. This can have one or more of the following causes.
1. IP address or hostname in JDBC URL is wrong.
2. Hostname in JDBC URL is not recognized by local DNS server.
3. Port number is missing or wrong in JDBC URL.
4. DB server is down.
5. Firewall issue.
To solve the one or the other, follow the following advice:
1. Verify and test them with ping.
2. Verify it based on my.cnf of MySQL DB.
3. Restart the DB.
4. Verify if mysqld is started without the --skip-networking option.
in the below case, --skip-networking is enabled
$ps ax | grep mysql | head -n 1
/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid --skip-networking
5. Make sure line skip-networking is commented in /etc/my.cnf
6. Disable firewall and/or configure firewall/proxy to allow/forward the port.
7. Look for the bind-address setting in my.cnf on the server, and make sure it's listening on the IP address(or hostname).
7. Replace bind-address = 127.0.0.1 with bind-address = 0.0.0.0 in my.cnf file. my.cnf file is available at /etc/mysql folder
Note: Alternatively (and less securely!) the above step7 will set it up to listen on all addresses - local and remote: bind-address = 0.0.0.0
8. By giving proper permissions: GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'password' WITH GRANT OPTION; FLUSH PRIVILEGES;
Hope it helps!. Thanks
