Standardization in Cloud Computing

Transcription

1 Standardization in Cloud Computing ARNE KOSCHEL, SABINA HOFMANN Faculty IV, Department of Computer Science University of Applied Sciences and Arts Hannover Ricklinger Stadtweg 120, Hannover GERMANY IRINA ASTROVA InVision Software OÜ Lõõtsa 2A, Tallinn ESTONIA Abstract: - Standards in cloud computing are still an issue, which needs to be addressed. This paper describes and compares six standards from five organizations: IEEE P2301, IEEE P2302, Open Cloud Business Initiative (OCBI), Open Cloud Initiative (OCI), Open Virtualization Format (OVF), and Open Cloud Computing Interface (OCCI). Key-Words: - Cloud computing, standards, interoperability 1 Introduction Since there is no generally acknowledged definition of cloud computing, we understand cloud computing as it is defined by the National Institute of Standards and Technology (NIST): Cloud computing is a model for enabling convenient, ondemand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. 1.1 Cloud Computing Nowadays the term cloud computing is a frequently used keyword within IT management. It is a well-known paradigm for cost savings and more flexibility. And it stands for an innovative part in the IT. Organizations are able to easily scale up their IT landscape with all required processes and applications while having dynamic business requirements. Cloud computing can be regarded as natural evolution of computing tendencies. It means a further step in abstraction, transforming the computing power in terms of infrastructure efficient usage, higher availability and last, but for sure not least, economic aspects. In particular, applying cloud solutions offers a number of economic advantages. Since cloud resources can be occupied and released in an elastic way, customers receive usage-bound bills and pay only for the resources they really used. This is referred to as pay-as-yougo pricing and allows for reducing fixed costs and converting them to variable costs. The absence of up-front capital expenses allows the capital to be redirected to core business investment. The different levels of abstraction in cloud computing falls into three layers: Infrastructure-as-a-Service (IaaS): In this layer the cloud only offers virtual machines to the customer. The cloud provider can give some predefined virtual machine image or let the users define their own images but the cloud provider does not care about any functionality except for the machine hosting. For example, the users have to think themselves about how many virtual machines they need. Platform-as-a-Service (PaaS): With this layer the cloud provider offers a framework to build and manage the customer s own applications in the cloud. The developers are bound to the restrictions of the framework but they often profit of automatic scaling of the framework. The most important advantage of this layer is that the developers do not have to care about any scaling of the applications. For example, if more computing power or higher ISBN:

2 login capacities are needed, the framework will care about it and provide the need. Software-as-a-Service (SaaS): This layer is constituted of ready-to-use applications such as Google Mail and Microsoft Office Live 365. It is directly addressed to the users and not to the developers of applications. In the actual situation every vendor specializes on one or more layers of the cloud stack (IaaS, PaaS and/or SaaS). Additionally the vendors offer mostly only a few cloud services, which are specialized on a certain sector. This leads to more problems and delays in the standardization. The most important problem is that every vendor offers its own proprietary API for its cloud services. That forces developers to build their applications upon a certain specialized proprietary API, since there is no standardized interface to access services in the cloud. So every developer has to deal with a new proprietary API while building applications. Changing the vendor is very difficult, as the whole application needs to get refactored to another proprietary API. 1.2 Goals and Structure As can be seen from above, there are a variety of elements within the cloud computing space, but also a lot of heterogeneity in technologies and terms. The goal and major result of this paper is an overview about major existing standardization approaches around cloud computing. Moreover, we provide a comparison of these approaches as another result. The remainder of this paper is structured as follows: The next section 2 details the motivation for our work. Section 3 describes and compares several standardization efforts around cloud computing. Section 4 summarizes our comparison results and gives a conclusion. 2 Motivation In 2010 the transaction volume of cloud services was more than one billion Euros just in Germany. More than 14 percent of today s business is already using cloud services. However, there are no standards yet but only guidelines on cloud computing or rather setting models. The reason might be with the organizations themselves they want to put out their own standards with no reference to already existing standards. They have recently begun to recognize this fact. On the other hand, standardization is needed for interoperability, which implies having a common exchange standard. Standardization is closely related to openness, as both have the goals of increasing competition in the market and improving market efficiency. 3 Cloud Computing Standards There are six main standards: IEEE P2301, IEEE P2302, Open Cloud Business Initiative (OCBI), Open Cloud Initiative (OCI), Open Virtualization Format (OVF), and Open Cloud Computing Interface (OCCI). 3.1 IEEE P2301 and IEEE P2302 In 2011, IEEE Standards Association founded two projects: P2301 Guide for Cloud Portability and Interoperability Profiles (CPIP) and P2302 Standard for Inter-Cloud Interoperability and Federation (SIIF). Both projects deal with the standardization of cloud computing and interoperability. But they are not finalized by now [1]. P2301 tries to create profiles for existing and unfinished standards in form of an intuitive roadmap. This roadmap integrates portability, management, interface, interoperability, file formats and arrangements in operation. P2301 is aimed to help users in the procurement, development, construction and usage of cloud-based products and services. Better portability and interoperability will be allowed with P2301 in the industry. One of the goals was to prevent multiple addressing of the same issues [2]. P2302 tries to beneficiate with the interoperability among cloud platforms. The standard will define a norm for topology, protocols, functionality and business management for reliable cloud-to-cloud interoperability and data exchange. The norm will create for cloud providers a transparency between users and applications. P2302 considers technical problems and appropriate infrastructure for the economic analysis and accounting [3]. 3.2 Open Cloud Business Initiative (OCBI) Open Source Business Foundation (OSBF) is a representative of Open Source industry; they promote the usage and development of open source ISBN:

3 software. By doing so, they try to encourage the dialogue between organizations, government institutions and political parties. In 2011 OSBF founded Open Cloud Business Initiative (OCBI) with two projects: Open Cloud and Interoperability for transparency and interoperability through open standards. The two projects are closely related to each other. Both take the perspective of users and demonstrate how organizations can use the new techniques. The project Open Cloud discusses the necessary framework, whereas the project Interoperability develops sample implementations [6]. The participants of the projects are Open- Xchange, Microsoft, Zimory, Talend, Suse Linux [4] [5] [6]. As a part of OCBI, they created six principles for IaaS, PaaS and SaaS. Not only the technical principles but also the legal and social aspects were considered. These principles are [6]: 1. Presenting user data and metadata in an open standard format 2. Services will be accessible via open standard interfaces 3. Service consumers can use services without any discrimination 4. User rights and access rights are determined by users for all the processed data 5. Service providers respect the rights of data, which have been authorized by owners 6. Modifications and extensions of open cloud services are voting through a community via appropriate infrastructure and processes. In the future, organizations can undertake the guidelines of OCBI through self-certification. However, OSBF can withdraw this standard by misuse [5] [6]. The main goal of OCBI is to create a concrete framework and push example implementations. 3.3 Open Cloud Initiative (OCI) Open Cloud Initiative (OCI) is a non-profit society; it was created in 2011 for the usage of open standards in cloud computing. The purpose was to achieve a legal framework with a number of requirements for the open cloud. Open Cloud Principles (OCPs) document helps these requirements to set up for cloud products and services [7]. OCI decides which products or services are compatible with the open cloud. All the decisions are based on the OCPs. The criteria are that all public documents are understandable and usable without costs and patent licenses. The OCPs call for more completeness, trueness and interoperable implementations at least one of which must be open source [9]. To use this standard, the following criteria need to be met [7] [10]: 1. Relevant standards have to be open, documented and published 2. Potential affected patents have to be free of fee 3. Trademarks are only permitted if they are in compliance and non-discriminatory 4. Client- and server-side implementations have to be under an OSI-approved license or conform to a public domain. Members are Noirin Plunkett (executive vice president of the Apache Software Foundation), Rick Clark (principal engineer for Cloud Computing at Cisco Systems) and Thomas Uhl (founder of the Cloud-German initiative cloud). The OCI s products and services constitute a relevant legal framework, using which the cloud computing community and providers can communicate [7]. 3.4 Open Virtualization Format (OVF) Open Virtualization Format (OVF) is developed by Distributed Management Task Force (DMTF). It has been an ANSI standard (INCITS ) since OVF is used in IaaS. The main target of OVF is to publish an open, secure, and extensible file format for specification of virtual appliances. Virtual appliances are pre-installed, pre-configured, and ready-to-use applications and software solutions. They are already compiled with an operating system on the underlying virtual machine. OVF establishes a transport mechanism for moving virtual machines from one hosted platform to another. Some major members are Dell, HP, IBM, Microsoft, XenSource and the biggest player in this area is VMware [11] [12] [13] [14]. Virtual machines in OVF can be packaged in a virtual appliances wrapped up in a single file. The creator of a virtual appliance can encrypt, compress and digitally sign the OVF content. OVF uses available packaging tools to combine one or more virtual machines together with a standards-based XML wrapper. Therefore, from the user point of view, OVF is both a packaging format for virtual appliances and a transport mechanism for virtual machines. OVF uses a container, which stores all the metadata and virtual machines. OVF allows for migration of virtual machines among clouds. OVF also defines certain aspects of the ISBN:

4 application running on a virtual machine, including CPU. The software life cycle for virtual appliances is: Develop Package Distribute Deploy Manage Retire. OVF is a first industrial standard, which affords interoperability inside virtualized environment and delivery of pre-configured, ready-to-deploy virtual solutions. The portability of OVF can be categorized into three ways [12] [15]: (1) running on a particular virtual hardware, (2) running on a specific class of the virtual hardware due to lack of device support by installed guest software, and (3) running on multiple classes of virtual hardware. 3.5 Open Cloud Computing Interface (OCCI) Open Grid Forum (OGF) is a community of gridcomputing users, developers and vendors. Open Cloud Computing Interface (OCCI) was found by OGF in It specifies a multiple protocol and an API for various cloud management tasks. The API enables interfacing between different IaaS cloud implementations. Originally, it was performed by co-chairs of Sun Microsystems, RabbitMQ and University de Madrid Computense. Currently, the membership is over 250 members large. The following institutions contributed to OCCI: Rackspace, Oracle, Platform Computing, GoGrid, Cisco, Flexi Scale, ElasticHosts, Cloud Central, RabbitMQ, CohesiveFT, Cloud Central, SOI, reservoir, Claudia Project Open Stack, OpenNebula and DGSI. OCCI operates in a distributed open community organization under OGF. A wiki and an inglist enables such cooperation. Anyone can join and participate freely. With the model of governance, the rights of each are protected by the OCCI working group [16]. The development focuses on [17]: 1. Interoperability: a. allowing different cloud providers to work together without the translation of data schema/format b. APIs are between facade/proxy for the understanding and/or the dependence of several APIs 2. Portability: a. no technical/vendor lock-in and the services b. allowing customers to easily move between suppliers and vendors and switch between them based on business objectives with minimal engineering effort for the promotion of competition 3. Integration a. specifications can be implemented either with existing middleware or by another provider 4. Innovation: a. realizing modern technologies OCCI provides a set of open joint-leading specifications supplied by OGF. OCCI specifies a REST-based protocol. In particular, it provides a RESTful interface by using HTTP as a transport protocol. OCCI uses key-value pairs in an HTTP header of the requests or responses. The API presents a service front-end framework to a provider s internal management. The current release of OCCI suits many other models. In addition to typical requirements for IaaS offerings, OCCI can be used for adding or releasing of cloud resources. OCCI functions are defined for the operational monitoring of services or to control the scaling properties of the resources [18]. The OCCI specification itself is modular and set out by three documents [19] [20]: 1. Core OCCI [20] [21] a. core elements of the standard are defined b. all other specifications are based on these core elements c. the definition of mixing objects allows for the mapping of scalable infrastructure by adding dynamic computing or storage system during operation time 2. OCCI Infrastructure [20] [22] a. specifying the IaaS domain resources, which include attributes and functions 3. HTTP OCCI rendering [20] [23] a. interaction and communication protocol for serialization and securing the requests b. addressed via HTTP by RESTful API. OCCI uses TLS to encrypt the communication. 4 Conclusion and Summary This paper described and compared six standards from five organizations: P2301, P2302, OCBI, OCI, OVF, and OCCI. The only complete standards are OVF and OCCI; both have their own specification, reference implementation and open source product. ISBN:

5 However, these standards are different because they were developed for different purposes. By contrast, OCI and OSBF are very similar to each other. OCI focuses on all open and independent patents. OSBF is doing the same but also involving patent-related components. The only organization, which applies all the existing standards (both complete and not complete yet), is IEEE. For this purpose, IEEE uses open source references, which do not necessarily describe what standards should be. Rather, they explain whether patent-prone components are permitted. However, since the two standards from IEEE P2301 and P2302 are still under development, it is not clear yet what results they will produce in the future. Tables 1 and 2 summarize our comparison results. Table 1. Summary of standards Table 2. Summary of standards (contd.) OpenStack [23] can be viewed as a reference implementation (see Figure 1). The whole implementation is written in Python and available under Apache License v2.0 as free software. The project was found by NASA (Nebula) and the U.S. Rackspace. The aim of the project was to replace the entire cloud architecture with separate modules or stacks, which can be used standalone. References: [1] IEEE standards: [2] IEEE P2301: tml WG.html [3] IEEE P2302: tml WG.html [4] OSBF: cloud/ [5] OSBF: [6] OSBF: iner OpenCloud-vfinal.pdf [7] OCI: mehr-standards-in-der-wolke-open-cloud- Initiative-gegruendet html [8] OCI: [9] OCI: [10] OCI: [11] wikipedia OVF: Virtualization Format [12] DMTF OVF: uments/dsp pdf [13] DMTF OVF: [14] DMTF OVF: [15] VMware OVF: whitepaper specification.pdf [16] wikipedia OCCI: Cloud Computing Interface ISBN:

6 [17] OCCI: [18] OCCI: [19] OCCI: [20] OCCI: [21] OGF OCCI: [22] OGF OCCI: [23] OpenStack: Figure 1. Cloud interoperability ISBN: