cloud computing issues and challenges for ultimate ...crc.aut.ac.ir/cloudcourse93/papers/cloud...

First CSUT Conference on Computer, Communication, Information Technology

November 16 – 17, 2011 Department of Computer Science, University of Tabriz

Cloud Computing Issues and Challenges for Ultimate Interoperability

Morteza Sargolzaei Javan, Amirkabir University of Technology, [email protected] Mohammad Kazem Akbari, Amirkabir University of Technology, [email protected]

Abstract: Interoperability is one of the most important challenges in the cloud computing scope. In order to overcome the problems of interoperability and build a global cloud standard, we must have a clear vision about where the clouds are heading. This vision indicates the future trend of clouds, without which one would be lost. In this paper we are planning to predict the future by looking at the pathway that different clouds from various vendors are going to, from both business and user viewpoints. In other words, we are going to investigate the cloud development trends and the destiny that they have not reached yet. With this, we can predict wind direction and see future needs in achieving ultimate interoperability. At the

end, all important issues in this content are highlighted.

Keywords: Cloud Computing, Interoperability, Standardization, Security

1. Introduction Cloud Computing is one of computing systems paradigms that make a sense of IT infrastructure as a “Cloud” from

which businesses and users are able to access applications from anywhere in the world on demand. Thus, the computing world is rapidly transforming towards developing software for millions to consume as a service, rather than to run on their individual computers [1]. An important problem in this computing paradigm is interoperability. For example a user wants to use vendor A's storage cloud while using vendors B and C's business services and finally wants to feed their outputs into the application provided by vendor D for further analyzing. This looks similar to traditional personal computers which we used a single computer with a couple of applications that could work together.

We will see that the interoperability is one of the most important challenges in cloud computing. The Cloud Computing Interoperability Forum [2], Open Cloud Consortium [3] and Cloud Interoperability Magazine [4] and some projects like Thrift [5] –A software framework for scalable cross language services development, are some of recent initiatives that emphasize importance of interoperability in the clouds. Also the ICWS panel discussion saw standardization of cloud services and data definitions as necessary solutions to interoperability issues (Figure 1).

Figure 1: Enabling the cloud for the enterprise. Cost and flexibility benefits are enterprise-ready, but security, performance, and

interoperability need significant improvement. [6]

If we don’t have a common standard for the cloud products, we couldn’t have a " global cloud computing

ecosystem whereby organizations are able to seamlessly work together for the purposes for wider industry adoption of cloud computing technology and related services. A key focus will be placed on the creation of a common agreed upon framework / ontology that enables the ability of two or more cloud platforms to exchange information in an unified manor" [2]. Therefore we will try to first predict the course of clouds and list the most important issues that should be prepared in this regard which would be like doing strategic planning for the cloud.



This paper is organized as following: An overview of current cloud computing approaches is presented in Section 2. In sections 3, one of current trends is presented. Our methodology is presented in sections 4 and more details are discussed in section 5. We would describe raised issues in sections 6 and 7. Finally, section 8 concludes the paper and outlines some further investigations.

2. Cloud Computing Overview

There is no common definition for cloud computing. That’s because cloud computing involves researchers and engineers from various backgrounds, e.g., Grid computing, software engineering, data storage. They work on cloud computing from different viewpoints [7]. In order to have an initial vision of the cloud, we first must have a look at the approach which two pioneers of cloud computing expressed in an interview published at IEEE Internet Computing [8].

Run Daniel, Vice President and Chief Technology Officer of Hewlett Packard’s cloud services strategy, said that "many cloud capabilities are being delivered today over standard Internet protocols". The user experiences frequently being Ajax based, delivered in the browser rather than through the clients, and then what’s in between we think of as cloud platforms. A lot of the virtualization and automation technologies that we’re building are really focused on improving the profits of that style of delivery, which is economical. We have things with persistent availability that we push into the cloud, and that stuff is pervasive and persistent; it’s there all the time. Being able to use the cloud to find experiences in a broader way is really exciting, and if we do that well, we can make technology useful for a much broader group of people.

Franco Travostino, a Distinguished Architect at eBay, said that one distinction between grids and clouds is that the cloud came out of the Web 2.0 and its impact is when or where you go from 2,500 users to 30,000 users, adding several thousand users every hour. That type of highly participatory and highly on-demand response is new. Anybody who can appreciate a variable cost proposition has to benefit from the cloud. We always have to keep in mind four different dimensions: people, processes, information, and technology. Also if we overcome trust [issues] and gain confidence in the fact that a cloud can be managed the same way or even better than how we do it internally within a corporation, we should see a lot of services built upon clouds, just as we have seen a variety of utilities being built in other industries. Virtualization advances to an extreme point which you won't have any loss of confidentiality and private data, even if the operating system is compromised.

In [9] this question is planed that is the cloud a new phenomenon? And if is it true, why is there no common definition for it despite its rapid growth and development. Also the author expresses three different ideas in this field. The first idea comes from "Navigating the Next Generation Application Architecture" by Chuck Hutchinson, Jeff Ward, and Karen Castilon, that have seen the cloud as a convergence of current technologies and discussed about how the organizations react against it. The second idea is from [10] that has seen the cloud as a new phenomenon for service and resources delivery in the Internet with the goal of providing "On demand computing instances" and "On demand computing capacity". The third idea comes from [11] that illustrate ontology of the cloud for better understanding of current cloud services. In [6] the cloud is seen as a concept with different meanings for different people. IT as a Service (ITaaS) for the application users, that provides computing, storage and applications over Internet, A platform for developers to develop and run their software at the Internet scale, and a massive and distributed datacenter for the administrators and infrastructure providers.

3. Cloud Computing Trends

The trends in cloud computing are mostly discussed from the business point of view. For example in [14] ten cloud computing trends have been discussed. The author notes that "Cloud computing is just like the weather; it blows this way and that, and no one really knows exactly where it’s going or what the cloud will cover". Also he tries to express how the cloud resources will change, or how the organizations will utilize the clouds; "Large enterprises are building their own private clouds", "Cloud computing will shift the skills needed by IT workers", "IT departments will shrink as users go directly to the cloud for IT resources", etc.

Some other kinds of investigations, for example in [1], have used a Google search trend to show that the cloud is becoming more popular (Figure 2). In this paper we have analyzed the issue: "where the cloud is going?" from another aspect. We have also used Google trend analysis as an input to our methodology.



Figure 2: Google Search Trends

4. Trend Analysis In this paper we will try to forecast the cloud's moving path. Trend analysis (trend extrapolation) is a forecasting

method based on identifications, historical data, observations, and ongoing changes. The point of trend analysis is to identify the trend early, while it is still likely to continue in the future [15]. It attempts to extend known data points to regions beyond the timeframe of known data points, almost always in an attempt to predict future values with some degree of probability. However, the assumptions made are critical [16]. The result of trend analysis by Google is used to determine Computing Trends. SaaS which is another trend of Internet Applications is also part of Cloud layers. Cloud computing is going to be standardized in a way which standard APIs in the SaaS layer will be part of this standardization process. This standardization will provide interoperability in all three cloud layers as shown in Figure3.

Figure 3: Analyzing Methodology

In this paper we focus on trends of how the need changes over time and causes the clouds to be formed. We will see that the clouds follow these needs and so predictability will be achieved according to future needs.

5. Our Cloud Computing Vision

We firstly want to analyze the pathway the Internet takes to reach the clouds. At the past, different sites provided their services independently. Each company established its own ".com" and users had to sign up in many sites for their different needs. The account that was created in one site couldn’t be used in another. The only connectivity that could have been seen in this stage was the usage of hyperlinks. Therefore there was a total lack of interoperability unless simple hyperlinks were used (Figure 4).

Internet Apps Trends Computing Trends

Cloud Computing SaaS

Standardization Standard API

Ultimate Interoperability

Interoperability

PaaS

SaaS

IaaS

Interoperability referring to the ability of diverse components

and systems work together (inter-operate)

Path toward interoperability from two different views

Cloud Computing

Grid Computing



Figure 4: Hyperlinks, the earliest way of interoperability

The next step in interoperability was introducing some projects like OpenID [17] that enabled the ability of accessing and using different services in different sites by a single account created in another site.

In this kind of development, the interoperability is just done for the authentication service. In other words some sites share their authentication service among other sites. But still the other services remain isolated (Figure 5).

Figure 5: Open ID, an evolving way of interoperability [18]

By introducing SOA, web 2.0, and new technologies, cloud computing appeared and interoperability increased by new ways of interactions and service delivery. In the cloud field, it is possible to utilize different cloud layers to share data and services among sites. For example one can upload a movie in YouTube and share it in Facebook -despite them being two different sites, someone else could comment on it in Facebook or share it again. This was a forward step in interoperability (Figure 6).

Figure 6: Cloud logical diagram [19]

Clearly in such environments, working with applications among different sites is similar to working with applications on an individual computer. The trend is toward a vision which that the borders between different domains are eliminated and users would have a sense of using their personal computer while surfing the Internet. This could also be called as a SSI in the Internet scale. A single system image (SSI) is the property of a system that hides the heterogeneous and distributed nature of the available resources and presents them to users and applications as a single unified computing resource [20].



In the ultimate interoperability stage (Figure 7), each user could be working on the Internet while having the same experience of working with his personal computer. For example he would be able to work with an online application to produce some data and then share them with other applications in a real-time manner for another type of processing and analyzing. All of these could be done transparently from the user's perspective. But from the vendor and infrastructure providers' point of view, there are many technical and non-technical issues that should be overcome to gain ultimate interoperability.

Data portability, performance, data sharing, etc, are some technical issues. Cloud computing has a flexible infrastructure to facilitate many of these issues in its underlying layers. But still some security based issues remain. How much could we trust clouds in a shared space? How does our privacy and identity remain safe when data is shared among different sites, applications and vendors?

Figure 7: Clouds in future, ultimate interoperability

Business models to support this full interoperable computing environment and pricing models for the service providers are some non-technical issues that should be considered too.

6. Ultimate Interoperability Considerations

As shown in Figure 8, Ultimate interoperability would be the future of cloud computing.

Figure 8: Ultimate interoperability is the future state of cloud technologies.

Cloud Computing Interoperability Forum (CCIF) It is a vendor neutral, open community of technology advocates, and consumers dedicated to driving the rapid adoption of global cloud computing services, focused on building community consensus, exploring emerging trends, and advocating best practices / reference architectures for the purposes of standardized cloud computing [2]. Despite the fact that they are developing a Unified Cloud Interface (UCI) Project to create an open and standardized cloud interface for the unification of various clouds API's [25], they haven't yet shown a clear view of what will be achieved in the future and where the clouds are heading. Also there are many technical and non-technical issues that should be considered to gain ultimate interoperability in clouds.



Technical Issues: - Data portability is an important concept in interoperability which refers to the amount of data which is

moveable between the applications, sites and clouds. This feature is important if we intend to increase interoperability of clouds among each other.

- Data Stickiness refers to the degree of data residing on the cloud. If you couldn't extract your data from the cloud, it will be assumed fully clinging on to it. But if you could extract it or download it into your computer, it won't be considered sticky anymore. This feature is important if we want to increase the interoperability of clouds with desktop applications.

- Data Quality: In order to increase portability or decrease stickiness, it is necessary to consider Data Quality. It is a Business Intelligence concept that refers to data standardization and reducing or avoiding dirty data that is fed into the system [21]. Clearly, cloud standardization could not be met if data within it isn't standard.

- Performance: This is another requirement that needs to be increased for real time interoperability and to provide more reliable services. If we keep data as near as possible to users, we could better maintain the performance. Virtualization is an enabler technology for this purpose. Virtual machines could be able to move across the cloud and still be kept near the users geographically to provide reliable services for them. But still the performance of physical machines itself should be considered.

- Security: How could we provide security in a shared cloudy space? This is not just about encryption methods, it is also about the soft security issues like Trust and Privacy. Such issues are usually caused because the users couldn't see into the clouds [22]. Thus these models must be incorporate into cloud computing to cover all kind of cloudy services and models and help users to have a sense of the clouds' inside. A good Trust model must be able to give a user the confidence of using the clouds without concern of what is happening within them.

Non-technical Issues: - Business Models and Pricing models: This is about how the ultimate interoperability environment could be

supported by the providers and businesses. We need new business models and pricing strategies to be used in the borderless computing environment. Therefore we must prepare our company and plan for it in advance.

7. Security in the Ultimate Interoperability

Trust, Privacy, and etc, are some of the open issues which are common between all three layers and need separate solutions for each individual layer. Also they have a new role in the Ultimate Interoperability of Cloud Computing.

Trust: How would we provide security in a shared cloud space? This is not just about encryption methods. It is also about the soft security issues like Trust and Privacy. Such issues are usually caused because the users couldn't see into the clouds [22]. Thus these models must be incorporated into all three layers of cloud computing to cover all kinds of cloud services and models and help users to have a sense of clouds' inside. A good Trust model must be able to give a user the confidence of using the clouds without concern of what is happening within. The Ultimate interoperability tends to have users trust the cloud just as their personal computer, but current trust systems are unable to provide this.

Privacy & Identity: Identity of users would be more important, because the Ultimate Interoperability encourages users to face the entire cloud with a single identity in order to get all benefits of the cloud. Therefore we need strong privacy mechanisms in all three layers to maintain user's privacy and identity. Some activities like OpenID are an example of this requirement (Figure 5).

Fraud: Cloud Computing providers are actively being targeted, partially because their relatively weak registration systems facilitate anonymity, and providers’ fraud detection capabilities are limited [26]. In Ultimate Interoperability, fraud would be even more possible because of the lack of monitoring systems and that we could not see what is happen within the clouds. Fraud is also a common attack to trust and privacy systems.

Context: Determination of how trustworthy an agent is depends on the context of the activity. Ultimate interoperability causes a seamless environment with variety of services and contexts. So we need context based security systems as well as context based trust, privacy and fraud detection systems to meet cloud environmental requirements. The Ultimate Interoperability would be shown borderless from the user's point of view. Thus context is the only factor that could be used to identify the differences between services and service providers.

Virtualization: It is the most enabling technology of cloud computing. Virtualization lets a single PC or server simultaneously run multiple operating systems or multiple sessions of a single OS, that enables easy scalability and the flexible creation and dismantling of resources that customers need only temporarily for special projects or peak workloads [23]. It is a way of increasing security in cloud computing [8], but how can we use virtualization to increase security concerning its own potential vulnerabilities? For example in the IaaS layer, hypervisors have full controls over the physical resources and the VMs running on top of them, so any vulnerability in this layer is extremely critical. Exploiting the hypervisor potentially means exploiting every VM [27]. Each layer has its own contextual information as well as each service has. The contextual information could be used to implement trust, privacy and fraud detection



systems in each layer. And if we want to have a good solution for Trust, Privacy and Fraud detection systems, we must start from the hypervisors as they are the building blocks of Cloud infrastructure.

8. Conclusion

In this paper we clearly predicted where the clouds are going in order to be ready in advance for future needs. At this point we must mention that the exposure of the cloud is a step toward enabling pervasive computing. With the vision drawn in this paper, we will have a unified computing environment provided by the clouds. This unified computing environment is exactly one of pervasive computing requirements, where the data could be accessible everywhere and anytime with high performance and real time computing. This could not be gained unless we reach the ultimate interoperability point in cloud computing.

References

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[25] UCI Project, http://code.google.com/p/unifiedcloud

[26] Top Threats to Cloud Computing, Version 1.0, Cloud Security Alliance, March 2010

[27] Cloud Computing- Benefits, risks and recommendations for information security, European Network and Information Security Agency, Nov 2009

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