max_used_connections

The MariaDB Connection ID exists since long ago. So why bother about the Connection ID? Because it is interesting and you can do some interesting things with the Connection ID like tracking statements in your connections and find where they come from your application code.

The MariaDB Connection ID is a strictly monotonic increasing number starting with 1 at server restart:

How many connections can be opened concurrently against my MySQL or MariaDB database can be configured and checked with the following command:

SHOW GLOBAL VARIABLES LIKE 'max_connections';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 505   |
+-----------------+-------+

If this limit was ever reached in the past can be checked with: