Running your database cluster on AWS is a great way to adapt to changing workloads by adding/removing instances, or by scaling up/down each instance. At Severalnines, we talk much more about scale-out than scale up, but there are cases where you might want to scale up an instance instead of scaling out.
In this post, we’ll show you how to change instance sizes with respect to RAM, CPU and IOPS, and how to tune your Galera nodes accordingly. Moreover, this post assumes that instances are launched using Amazon VPC.
When do we need to upgrade an instance?
You typically need to upgrade an instance when you run out of server resources. This includes CPU, RAM, storage capacity, disk throughput and bandwidth. You must allow enough headroom for your database to operate and grow. Performance tuning will allow you to get the most out of your servers, but in some cases, this might not be enough.