Cloud computing, explained Salvador Pérez Crespo Tecnologías Cloud computing involves two major decisions. The first is the position companies should take up when adopting it, meaning how and what they should use it for. The other is which part of hosting providers business is threatened, and what they could do to counteract disintermediation. The purpose of this article is to attempt to explain the concept of cloud computing in a simple way, rejecting absolute precision in the interests of simplicity, and point out the key factors enabling its implications to be analysed. Principally, for two reasons, because, as with all recent concepts, there is great confusion surrounding its meaning, and because the terminology used classifies the agents by using a set of acronyms which complicate even further something which, essentially, is not complicated. The basic nomenclature The most widespread vision of cloud computing is the one which defines it from the point of view of the user. According to this point of view, cloud computing is a style of IT in which all its elements
(principally software and equipment) are supplied as a service via the Internet; in other words, they are sold so that the user pays only for what he or she uses (software, hard drive storage, database access, etc.) and does not acquire the good for unlimited use. From this point on, we have to admit that the nomenclature in use is confused, with acronyms like XaaS, X-as-a-Service being used to classify up to three types of service which have little in common. On the one hand, we have the leasing of IT equipment associated with the name IaaS Infrastructure as a Service, and the rental of software, which is associated with the name SaaS Software as a Service. In both cases, users are principally the same as those with traditional IT: private individuals, companies, and Administrations. On the other hand we have the leasing of environments for development and execution of IT applications or PaaS Platform as a Service. In this case, use is aimed at the professional in the sector, the IT applications developer, as it is very rare for these services to be contracted by the end user. To increase the confusion, the novelty of the terminology means there is still confusion with a multitude of more traditional terms. This is mainly because the concept of cloud is an evolution of other concepts which have already existed in the world of IT for quite a few years now. An example is shown in the attached figure, which represents the cloud of tags on a popular site devoted to the topic. It shows the great relationship it has with a previous concept, utility computing, which is much less popular but very similar in terms of the concept it represents. And having reached this point, all that is left is to explain the qualifying term cloud when applied to the word computing, which gives us the more technological view of the term. This has to do with both the software and the IT equipment being moved from the user s premises to the Internet, with the latter being understood as a large computing cloud where the IT applications are executed. After the main concepts, the most frequent questions about cloud computing Now we have cleared up the main concepts, let us move on to solving the most frequent questions about this topic. How virtualisation fits into this scheme It is a good idea to clarify another of the concepts usually linked to the idea of cloud computing: virtualisation. The aim of virtualisation is to run on one computer two or more instances of an operating system simultaneously, or in general, two or more different operating systems. This is used, for example, to run Windows and Linux simultaneously on the same computer. This trick is carried out by software which is run beneath the operating systems and which orders access to the basic resources of the computer: CPU, and drives, etc. If we think about a calculation centre, virtualisation allows applications to be run on the same computer which previously had to be run on independent computers. The main advantage is making the most of resources and the saving arising from this. And if, in addition, the virtualisation software is so efficient that it can coordinate the basic resources of not just one computer but several, then the operating systems will be run in a cloud of computers; hence the similarity with the computing cloud. And when this occurs, the possibilities are multiplied: operating systems can be concentrated on fewer computers at times of low activity, operating systems can be migrated to more modern computers when greater performance is required, etc.
Bearing this in mind, virtualisation could be an IaaS when what is leased is the hosting of a virtual machine in a data centre. In this case, what is leased is a computer. But virtualisation could be an SaaS if what is rented is a virtualised workstation, in other words, the use of a virtual computer. What are the most popular services? Let s begin with SaaS Software as a Service. Here we find services of all kinds. For the more professional environment we find offerings such as those of Salesforce, which sells CRM software as an online service, or Basecamp, which sells online software for project management. All kinds of users now have a multitude of tools available which replace typical desktop applications with online versions which are run from a web browser. The most popular ones are office automation applications at companies like Google or Zoho, but there are also online applications as complex as software for image processing and even video. Amongst the examples of IaaS Infrastructure as a Service, the most obvious is that of leasing computing infrastructures, in other words the hosting of virtualised computers. In this area we find offeringss such as Amazon Web Services EC2 and GoGrid. IaaS also includes some basic software computing services. These are basic components which allow the creation of applications which are run in a distributed manner on various computers located in different places and even provided by different companies. Here we find basic database services (such as Amazon SimpleDB) or task management services (such as Amazon Simple Queue Service). There are some services which are halfway between being an SaaS and an IaaS. Here we are talking, for example, about services such as network storage. In this case the limit is marked by the interface which is used to access the service. In other words, if the interface for relationship with the service is a man-machine interface (as in services such as Box.net, Dropbox or similar) we are talking about SaaS. But if the interface is a programming API (as in the case of Amazon S3), then we are talking about an IaaS. But this is just one possibility, as there might be a different criterion which would make the classification different. Finally we have the PaaS Platform as a Service. What is offered here is an environment containing everything necessary to support the complete life cycle of online applications creation. The most representative example is, by far, the Google App Engine development environment. This allows access to the same computing infrastructure used internally by Google, including its distributed execution techniques. What cloud computing offers For the programmer, cloud computing offers the dream of having infinite computing resources. But it is a dream which, in practical terms, we could classify as sufficiently real. It is something like what happens with current cryptography systems, which are not completely safe because all of them can be broken, but which are sufficiently difficult to break to be considered sufficiently safe. For companies and Administrations (and for many private individuals), and above all for applications which will evolve with time, cloud computing offers the possibility of starting out with a little, safe in the knowledge that growth will come in an ordered manner in terms of resources and associated costs. It is ideal for accessing applications which have a very concentrated use in short periods of time. For these cases, cloud computing avoids the need to have IT resources which remain idle for long periods of time and are, thus, considerably underused. From a financial point of view, the price structures entail a conversion from CAPEX to OPEX, the principal effect of which is a relief of pressure in the short-term (particularly important in periods of economic slowdown and considerable pressure on cutbacks in capital expenditure) and the transfer of the risk to the service provider.
Comparing global costs If we think globally, we find factors for and against cloud computing. Obviously, the cost of communications increases because the data are stored further away from the place where they are going to be used than occurred in traditional solutions. But not that far away. More than likely, the computing cloud will not be a deeply decentralised structure with an extreme degree of dispersion and complexity. Rather, there will be a small group of computing centres which will group together the majority of the information. After this there will be a long line of disperse servers, but which together will not provide the majority of the information handled. On the other hand, the cloud world allows savings linked to factors belonging to the computing context. This is explained by the fact that, at the moment, the costs of cooling, electrical power and physical space cost around two to three times more than the IT systems. With this premise, it is beneficial to locate computing centres in places where the electricity is cheap, where the temperatures are low or where the cost of land is low. And preferably where all three of these occur together. Taking this into account, it is not surprising that companies like Google are devoting research resources and intensifying their patents activity in cooling techniques, location of data centres in the sea, and even the generation of cheaper energy. Overall, the advantages ought to be greater than the disadvantages, and lead to a situation of lower total cost. What is needed to be a cloud computing provider The advantage of cloud computing is that almost anyone can take part in it. It is not necessary to have either a superlative size or an excessive technological advantage. Software as a service is such an elementary model that it applies to agents of almost any size. However, if we focus on the large computing clouds [1], the situation is very different. At least in the short term there should not be more than a small number of large computing clouds. Although, who knows, the forecast was also that five computers would cover everybody s computing needs. Or was that five computing clouds? Whatever the case, the conditions necessary to become one of these large computing clouds are: To have made great investments in the construction of data centres. This includes both the companies which did so with similar purposes (such as the providers of hosting services), and those which did so because their business required it (as in the case of companies like Google and Amazon). What is curious is that it was the latter and not the former, i.e. the least close, which launched themselves into the provision of services. To have large scale infrastructure management capacities. Such as those possessed by the telecommunications operators, who have the knowledge and the systems to manage large and intricate communications networks. To have a user-friendly management interface so that users are able to handle the service easily. We must not forget that cloud computing goes hand-in-hand with the web 2.0 movement. In this environment, complex interfaces which are only suitable for very specialised users are not understood. Rather the tendency is for them to be used by almost anyone, and with very little or no learning time. For the case of PaaS-type services, there is a requirement to have technology which at the current time is mainly owner technology, a long way from any attempt at standardisation.
The situation has no clear winners, rather well-positioned agents. However, the reaction capacity of the worst positioned is beginning to be reduced slowly. If measures are not taken soon, the biggest loser will be the traditional hosting provider. Technology suppliers and the role of open code The services offered in cloud are services which make more sense when they are offered in bulk. And like any mass service, the greater the size, the greater the impact of reducing each of the individual costs. In the area of cloud the same is true. Above all because, in the IT world, a large proportion of the solutions are so mature that their costs are getting increasingly closer to zero. And in the long term, when the services are commoditised, there will be a clear competitive advantage for anyone who has an infrastructure which is cheaper to build and maintain. The problem is that, because they are large infrastructures, any decisions taken at the beginning will be difficult to change. With these premises in mind, decisions such as the following, which do not form an exhaustive list, could be taken: Use Intel architectures as the basic computing infrastructure: because they are the most used, they are the cheapest. For the same reason of popularity, these platforms accept a large number of operating systems. Use open code software wherever possible. The cost is reduced because there is no need to pay for licences for use. But, in addition, free software becomes an essential element when serious modifications have to be made such as, for example, linking the cloud services to other provider assets; an example might be the network in the case of a telecommunications operator. The problem of the APIs which turn customers into captives Captives in the IT world have always existed. They are the ones who use a word processor with an owner format, those who provide a database manager with owner interfaces, or those who use the customer s e-commerce tool. In the classic IT world, you used to have alternatives in part of the value chain. For example, you could continue to be a captive of Word but you could move from running it on a Windows operating system to the Apple operating system. Or you could carry on using the Oracle database manager, but use it on a Windows computer instead of a Sun computer. In the cloud world, the situation is different and much more radical. For example, if you attach yourself to an IaaS-type network storage service, there is an exit barrier linked to the fact that the applications are created specifically to use the service API. Thus far, everything is normal. The problem is that the API is linked to the rest of the service provider s infrastructures, which means that you are not only captive to the service, but also to all the elements in the service value chain, something which did not happen before.
The greatest risk comes with PaaS services (such as the Google App Engine) because they provide not only a part of the functionality or the services, but the whole applications creation environment. In this case, the cost of leaving would involve completely rewriting the application. In other words, the captive customer has more value than before. This is why it becomes even more important to be one of the leading players in this market, to make captive the largest number of customers as soon as possible. The open cloud manifesto The first major players in the cloud world were companies like Amazon and Google, two non-conventional players in a natural market for hosting companies. To compete against them, one of the possibilities is to commoditise the service anchoring elements, thereby flattening the exit barriers for users of cloud computing services. In this sense, the most relevant initiative at the moment is the open cloud manifesto, promoted by IBM and to which Telefónica has been signed up since it was published. The manifesto, which can be found at www.opencloudmanifesto.org, adopts a didactic tone to explain to users the change of models posed by cloud services, and the risks to which they might be subjected if they take a hasty decision. Conclusion: what we can expect Firstly, we can expect an early reaction from providers of hosting services. To begin with, these will be solutions which, for the most part, will be extensions of the range compared to their traditional products. These will be encouraged by the fact that data storage must be governed under different legislations in different countries [2]. Or because we can foresee Administrations demanding local clouds to store and process data. Evidently, this type of service goes against the cloud philosophy, which is global, and would unleash a trend towards local services in the cloud world. In the long-term, the PaaS Platform as a Service proposals can be seen as the real future of cloud computing. This would include initiatives like the Google App Engine, Microsoft Azure or Sun s Caroline project. «Paper included in the bulletin ekiss nº104, a weekly internal publication of Telefonica» REFERENCIAS [1] A large computing cloud is a mega farm of servers acting in a more or less coordinated way. The two largest clouds at the moment are Google s and Amazon. [2] The traditional hosting provider has the chance to begin offering cloud services adapted to local legislations, by filling a gap in the market which might not be covered by global clouds. [3] texto referencia