What's the maximum number of concurrent connections that TiDB supports?

By default, there is no limit on the maximum number of connections per TiDB server. If needed, you can limit the maximum number of connections by setting instance.max_connections in the config.toml file, or changing the value of the system variable max_connections. If too large concurrency leads to an increase of response time, it is recommended to increase the capacity by adding TiDB nodes.