Auto-scaling is a function that allows you to provision and launch new instances whenever there is a demand. It allows you to automatically increase or decrease resource capacity in relation to the demand.

https://avinetworks.com/glossary/auto-scaling/

When we think about Microservices, we think about Scaling and this is the principle which takes care of that. As per this best practice and principle, each Microservices should be designed to automatically scale up or down in response to changes in demand, to ensure that the application remains responsive and available.

For example, if the number of users accessing a microservice increases, that microservice could automatically spin up additional instances to handle the increased demand.

In real world, tools like Kubernetes can automatically scale up and scale down by creating new instances of your Microservices and destroying them once they are no longer required.

If your Microservices is not designed for automatic scaling then it wouldn’t take full benefit of Cloud and tools like Kubernetes, so you must ensure that they are designed for scaling. If you are wondering how to achieve that, then stay tune, I will share more tips on how to ensure scalability of your Microservices in next article. 

https://medium.com/javarevisited/10-microservices-design-principles-every-developer-should-know-44f2f69e960f