Dive into the Cloud: Brief Technology Introduction
Cloud Computing is one of the most speculated terms in IT industry last couple of years. We call “cloud” lots of things, sometimes absolutely different. We’re starting the series of posts, dedicated to large set of technologies somehow related to Cloud Computing. We start our journey from the very beginning: let’s define cloud and understand what does it mean.
Once an elephant came to a small town. People had read and heard of elephants but no one in the town had ever seen one. Thus, a huge crowd gathered around the elephant, and it was an occasion for great fun, especially for the children. Five blind men also lived in that town, and consequently, they also heard about the elephant. They had never seen an elephant before, and were eager to find out about elephant.
Then, someone suggested that they could go and feel the elephant with their hands. They could then get an idea of what an elephant looked like. The five blind men went to the center of the town where all the people made room for them to touch the elephant.
Later on, they sat down and began to discuss their experiences. One blind man, who had touched the trunk of the elephant, said that the elephant must be like a thick tree branch. Another who touched the tail said the elephant probably looked like a snake or rope. The third man, who touched the leg, said the shape of the elephant must be like a pillar. The fourth man, who touched the ear, said that the elephant must be like a huge fan; while the fifth, who touched the side, said it must be like a wall.
They sat for hours and argued, each one was sure that his view was correct. Obviously, they were all correct from their own point of view, but no one was quite willing to listen to the others. Finally, they decided to go to the wise man of the village and ask him who was correct. The wise man said, “Each one of you is correct; and each one of you is wrong. Because each one of you had only touched a part of the elephant’s body. Thus you only have a partial view of the animal. If you put your partial views together, you will get an idea of what an elephant looks like.”
The moral of the story is that each one of us sees things exclusively within one’s point of view. We should also try to understand other people’s points of view. This will enable us to get a proper perspective on different situations and events.
What can we learn from this ancient story? One’s understanding of something is highly dependent on theirs perception of the thing. Those people who use SaaS say that Cloud is SaaS. Those who use VMware products say that Cloud is Virtualization. Those who use Apple products say that Cloud is synchronization service for their mobile devices. All of them are right. Cloud could be very different. But we need some kind of definition just to be on the same page when we talk about it. There are several of them, but here at ELEKS we usually use only one, called OSSM:
- On-demand: resource is already setup and ready to be deployed
- Self-service: customer chooses what they want, when they want it
- Scalable: customer can choose how much they want and ramp up if necessary
- Measurable: there’s metering/reporting so you know you are getting what you pay for
Let’s try to apply it to several popular “clouds”:
1. Amazon EC2. When you ask about new virtual machine it is ready to be deployed. It is completely self-service. You can choose how many instances do you want. And of course there are lots of reporting that allows you to measure usage. Passed.
2. Dropbox. When you ask about additional storage it is ready to be allocated for you. You can do it by your own. You can buy more space in case you want it. And you can see how much space do you really use. Passed.
3. Virtual server farm operated by your IT staff. If they have enough servers they are ready to deploy your VM on-demand. Usually you can’t allocate new VM by yourself, you have to ask your IT guys to do it. It could be scalable, but usually it is not measurable: you don’t have access to list of all your VMs and don’t understand how they are used. Failed.
Cloud computing is one of the most interesting areas of IT nowadays. Cloud market is growing very fast and producing new opportunities for businesses one by one.
Electric power analogy is very nice for better understanding of the future of the cloud computing. Almost no one have their own power generators nowadays. Same thing will happen with computing once: people will have thin terminals (e.g. mobile devices) that will be used for accessing massive computing facilities in the cloud.
Using OSSM definition you can check whether service is really cloud or you are victim of aggressive marketing that attach cloud label to anything in order to sell it. You can better understand key properties of cloud services when you build them.
Different service models allow you to manage only those parts of your IT stack you want to manage. With public, private and hybrid clouds you can share infrastructure with other people, own it completely or use some combination of the above.
See you next time. Stay tuned!