A best practice is a technique or methodology that, through experience and research, has proven to reliably lead to superior results. In this blog post, I will talk about few best practices that I have learned over the years which might help you in designing scalable web applications.
But before we talk about scaling best practices, we should define the meaning of scalability. Most of the people confuse scalability with performance. Performance refers to the capability of a system to provide a certain response time. Scalability can be defined as ease with which a system or component can be modified to fit the problem area in such a way that the system can accommodate increased usage, increased datasets, and remains maintainable. A system can be performant but might not be scalable. For example, a web application can be very responsive and fast for 100 users and 1GB of data, but it will not be considered scalable if it can’t maintain the same speed with 100 times the data with 100 times the users. You achieve scalable architecture when you can handle more load by adding more of the same stuff. You want to be able to scale by throwing money at a problem which means throwing more boxes at a problem as you need them.
Read full blog at https://www.openshift.com/blogs/best-practices-for-horizontal-application-scaling
Shekhar Gulati 