These days there is a lot of buzz around the word ‘scalability’ in IT world. The concept is actually not new, I have been designing scalable systems for last 9 years, but the idea has definitely changed since then.
How meaning of scalability has changed in last few years?
If 5-6 years back, I was creating a system to support say 10K users, and someone would have told me to make it scalable, I would have thought of making the system it in such a way that it can support double or may be 4 times or max 10 times the users in next 3-4 years. But with the applications like facebook, amazon, ebay, twitter the idea about scalable system is different. Now the user base can increase exponentially in matter weeks. And that is what every organization wants.
What is the impact of change?
Impact of the change is that now you do not want a system which will need a good amount of change if your user base is increasing. Earlier, as number of users used to grow slowly, it will give you time to think, design, redesign, upgrade the system, but now, as user base can increase with much more speed, you want a system which can scale up within minutes and it should be able to it automatically.
How to achieve scalability in today’s world?
As the demand has changed, so has technology. Cloud computing has made it much easier for us to create scalable systems. Key component choices to be made while creating a scalable solution
1. Design: Design of application/ code should be able to handle infinite load.
2. Database: If you are expecting your data load to grow beyond a few million, you might want to go for NOSQL over RDBMS.
3. Hardware: you should be able to add in new hardware and replicate the application on new servers within minutes. Cloud system can help you here.
4. Load balancing: If our application is getting distributed/replicated over multiple servers, we will need to take care of load balancing so that no server will choke.