Differentiating between private, public, and hybrid cloud
Alex is getting ready to leave the office at the end of the day when Raj walks up to him. He notices the gym bag Alex is holding.
Raj: So, are you planning on going to the gym after work?
Alex: Oh, yes. I am on a hybrid exercise plan this week.
Raj: Hybrid?
Alex: Yes. I do cardio exercises at home and for weight exercises, I go to the gym.
Raj: Nice, that doesn’t sound too different from hybrid cloud.
Alex: What’s that?
Raj: So, when you exercise at home, you use the private cardio equipment that you have bought, and it is used only by you. You maintain it and get more equipment if you need it. That’s a private gym. Similarly, companies may invest in hardware and software – that is, capital expenditure – to set up a private cloud, which gives them a higher degree of customization, and is fully controlled by an internal team. A private cloud may still host public-facing applications, but the companies get full autonomy in setting and maintaining them. Companies follow this path if they have some stringent latency or compliance requirements for their applications.
Alex: Ah, I get it – and when I go to the gym, it’s a public place. Anyone can pay a fee and use the equipment there. Isn’t that like a public cloud?
Raj: In a way, yes. The gym company sets up a location, maintains an energetic ambiance, hires trainers, puts in equipment, and may have other facilities too, such as lockers, a swimming pool, a sauna bath, and so on. If its pool of members keeps on growing, it will probably also expand its operations to scale its gym facilities. The gym will maintain security, follow local regulations, and a member just pays a monthly fee to use those facilities.
Alex: Interesting. Tell me more.
Raj: Now, sometimes, a company may not want to fully operate its applications from the cloud – or if they are in the midst of migration, they may end up with a hybrid model. Like when you want to exercise, you use your cardio equipment at home, and to use a sauna, you can go to the gym afterward. Similarly, a company may host a latency-sensitive or highly customized application on-premises in their private cloud, such as a custom database, and use a frontend, such as a web server, hosted on the public cloud. This sometimes gives them greater flexibility. Some companies also use the cloud as their failover mechanism – so if they have any issues with their private cloud, they may set up failover to the public cloud and return operations back to the private cloud once the problem is fixed. Another use case could be to launch a new project for which the private cloud may not have enough resources; then they can use the public and private cloud at the same time.
Alex: Does this not create connectivity issues?
Raj: Yes, but there are ways around it. In my last job, I was helping customers establish these network connectivity options – and believe me, these networks are much easier to establish now and are evolving at a rapid pace. Some of the options are almost 10 times higher in speed than our current network here.
Alex: Wow – but what about compatibility issues? I guess it won’t be as easy as drag-and-drop from on-premises to the cloud.
Raj: In fact, it is like drag-and-drop in some scenarios. Private and public cloud vendors are working together to create solutions that provide a way to migrate your applications seamlessly – and there is a plethora of third-party solutions available to facilitate this hybrid approach. I was amazed when I saw an application being migrated from a private to a public cloud without any downtime.
Alex: Without downtime? You must be kidding!
Raj: No, I am not. Yes, it requires some very specific networking configurations, but it is completely possible… and in a reverse direction too. Suppose after running a global campaign for millions of users on the public cloud, you want to bring your applications back to the private cloud; that is possible too.
Alex: Amazing. I am starting to understand it… but this is enough exercise for my brain today. I don’t think I can handle any more at this point. I’m going to go and do some physical exercise too. Do you want to join me on my walk up to the bus stop?
Raj: Thanks, but you carry on. Maybe some other time. I am going out for a pizza party with my ex-colleagues today.
Alex: Okay. Enjoy the party! See you tomorrow.
Raj: See you tomorrow.