Hosting a relational database server based on MySQL using the AWS RDS service choosing a t2.micro instance (1 GB RAM and 1vCPU), the engine automatically configures the maximum number of concurrent connections, based on the available memory, by using the formula for MySQL 5.7.21, as follows:
max_connections = (Available RAM - Global Buffers) / Thread Buffers
The preceding command will result in the following configuration for a db.t2.micro instance:
Nevertheless, if we scale the database instance vertically, to a db.m4.large with 8 GB RAM and two vCPUs, we will increase the concurrent connections available for this node, as following screenshot:
This change can be applied to a maintenance window as part of DBA operations, as shown in the following diagram:
The ability to scale the reading capacity is also available for databases on RDS using what are...