Qlik Talend Product: Cannot connect to database: Host xxxx is blocked because of many connection errors

[tomoya_suto]

The following error is shown next to Connection in Database Configuration page of Talend  Administration Center when using MySQL DB.

Cannot connect to database (null, message from server: "Host xxxx is blocked because of many connection errors: unblock with 'mysqladmin flush-hosts'") 

Resolution

1. Please check your environment if the reasons mentioned in the "Cause" section are affecting you to have many connections.
2. Unblock using "mysqladmin flush-hosts" as mentioned in the error.
3. There 2 things need to be done on the MySQL DB end with the help of your DBA for now.
   • Run the flush host command.
   • If there is a maximum connection until error value that you can set (For example: max_connect_errors in MySQL), please Increase the max number of connections on the DB end (set it to a higher value to handle more connections).
   • Please check the above, do the changes on the DB end, clear the cache on the Talend Administration Center end and do a restart of Talend Administration Center Application, this would help you to fix the issue.

Cause

This issue could be caused by two main factors in general

NetWork Connection

1. Network connectivity issues between Talend Administration Center Application server and the MySQL database server.
2. Firewall or security group settings blocks the connection.
3. Health check or port scan in other systems may be connecting to the server.>

MySQL DB

1. The MySQL server is down or not accepting connections.
2. Incorrect database connection configuration in Talend Administration Center Application.
3. The database server has reached its maximum connection limit.

Related Content 

How-to-clear-the-Talend-Administration-Center--cache

Environment

Talend Administration Center