Alternative MySQL cannot be installed due to exceeded limits

Symptoms

Alternative DBMSs like MySQL, MariaDB, PostgreSQL, and Percona cannot be installed.

The error «toomanyrequests: You have reached your unauthenticated pull rate limit» is displayed in the control panel log at /usr/local/mgr5/var/ispmgr.log.

Causes

Docker Hub request limits have been exceeded. The default limit is 100 requests per 6 hours.

Solution

Restrictions on an IP address are removed after 6 hours.

Authorized users can make up to 200 requests in 6 hours. If you have a Docker Hub account, run the following command to authorize:

docker login