Number of simultaneous connections connections in Aiven for MySQL depends on the available total memory on the server. We allow 75 connections per each GiB of usable memory. Usable memory is the total memory on the node minus operating system and management overhead, which is currently estimated at 350 MiB. The usable memory is rounded to nearest gibibyte.
So for example on a server with 3.6 GiB memory, you will get 3 * 75 = 225 connections and with 4.0 GiB memory you will get 4 * 75 = 300 connections. Note that the MySQL
max-connections setting is always set to one higher (e.g. 226 / 301 in the example cases) because there is usually one system process that consumes one of the available connections.