You don't use burstable instances for production workloads, and especially not for socket servers. These servers need to handle connection healthcheck pings ev

You don't use burstable instances for production workloads, and especially not for socket servers. These servers need to handle connection healthcheck pings every 30s. When you have lots of connection it adds. Also Phoenix Channles library has a deficiency where they parsing every ping, which is represented by a relatively large JSON message. For example in MQTT ping is binary and 2 bytes long only. T3 instances are the low cost burstable general purpose instance type that provide a baseline level of CPU performance with the ability to burst CPU usage at any time for as long as required. T3 instances are designed for applications with moderate CPU usage that experience temporary spikes in use. https://aws.amazon.com/ec2/instance-types/t3/ https://aws.amazon.com/ec2/instance-types/t3/