Mariadb: Cannot decrease max_connections to 1, ERROR 1231 (42000): Variable 'max_connections' can't be set to the value of '1'
This sounds like a regression as the MariaDB documentation for max_connections says the range is 1 to 100000.

I can do SET GLOBAL max_connections=1; in MySQL 5.7 and 8.0, but not in MariaDB 10.2 and 10.3 (tested on 10.2.21, 10.3.10 and 10.3.12). I get a warning rather than an error, though:

| Warning | 1292 | Truncated incorrect max_connections value: '1' |


And the value gets set to 10:

SHOW GLOBAL VARIABLES LIKE 'max_connections';
-&gt; | max_connections | 10    |


(I've taken the liberty of reporting the issue here.)

EDIT

The documentation has been updated to say the range is now 10 to 100000, and the bug report has a comment from Monty himself explaining the reason for the change - it was deliberate, so not a bug. (Basically, it was done to prevent unexpected behaviour/results.)