Demystifying the Cloud

Transcription

1 2012 Demystifying the Cloud This ebook explains the concepts of Cloud Computing in simple terms. The first three chapters introduce the key concepts and the terminologies of the Cloud. The remaining chapters cover the major implementations of the Cloud Computing including Amazon Web Services, Microsoft Windows Azure Platform, Google App Engine, OpenStack and Cloud Foundry. This is targeted towards the beginners and intermediate developers with a basic understanding of web technologies. Get Cloud Ready Janakiram MSV Janakiram & Associates 1 1/1/2012

2 About the Author A technologist at heart, I have been championing Distributed Computing for the last 14 years. In my current role of an unbiased, neutral Cloud Specialist, I offer strategic advice and coaching to enterprises and start-ups. I help them adopt and take advantage of the Cloud. Founder and driving force of an initiative called GetCloudReady.com, I enable Architects, Developers and IT Professionals to be ready for the cloud and thereby get people, processes, products and business applications to leverage the benefits of the cloud. My greatest imaginable dream is to continue to be the catalyst to the cloud revolution by being an independent authority on Cloud Computing as a Blogger, a Cloud Evangelist, a Speaker, an Advisor and Mentor to startups. I am also the chief editor at CloudStory.in where I blog about the latest trends in Cloud Computing. As a passionate speaker, I have chaired the Cloud Computing track at premier events in India. Having spoken at over 50 events in 2011, I have been consistently rated as the top speaker at premier technical events. The valuable time and work done at Amazon as the Web Services Evangelist and Technology Architect Cloud at Microsoft Corporation has offered me the breadth and depth of knowledge and expertise in the Cloud Computing domain. Prior to this, for about 10 years at Microsoft Corporation, I have been involved in selling, marketing and evangelizing the Microsoft Application Platform and Tools. Founded on a strong belief that technology needs to create a lasting impact on businesses, people and society at large; I relentlessly strive to deliver value to my customers and the community. My Coordinates Principal Consultant, Janakiram & Associates Cloud Specialist, Get Cloud Ready Chief Editor, CloudStory.in Janakiram & Associates 2

3 Chapter 1 Defining the Cloud Evolution of ISP There are multiple factors that led to the evolution of Cloud Computing. One of the key factors is the way Internet Service Providers (ISP) matured over a period of time. I am borrowing this analogy from Forrester Research. Evolution of ISP From the initial days of offering basic Internet connectivity to offering Software as a Service (SaaS), the ISPs have come a long way. ISP 1.0 was all about providing Internet access to their customers. ISP 2.0 was the phase where ISPs offered hosting capabilities. The next step was co-location through which the ISPs started leasing out the rack space and bandwidth. By 2012 Janakiram & Associates 3

4 this, companies could host their servers running custom, Line of Business (LoB) applications that could be accessed over the public internet by its employees, trading partners and customers. ISP 3.0 was offering applications on subscription resulting in the Application Service Provider (ASP) model. The latest trend of Software as a Service is a mature ASP model. The next logical step for ISPs would be to embrace the Cloud. The Programmable Web Web Services made the web programmable. They enabled the developers to look at the Internet as a class library or an object model. Protocols like Simple Object Access Protocol (SOAP), Representational State Transfer (REST), JavaScript Object Notation (JSON) and Plain Old XML (POX) fueled the growth of APIs on the web. Today every popular search engine, social networking site and syndication portal have APIs exposed to developers. Programmable Web Virtualization Virtualization is the most discussed term among CIOs and IT decision makers. Through Virtualization, the data center infrastructure can be consolidated from hundreds of servers to just tens of servers. All the physical server roles like Web Servers, Database Servers and Messaging Servers run as virtualized instances. This results in lower Total Cost of 2012 Janakiram & Associates 4

5 Ownership (TCO) and brings substantial savings on the power bills and reduced cost of cooling equipment. Virtualized Infrastructure Though the evolution of ISP, programmable web and virtualization are independent trends, they contribute to the evolution of Cloud Computing. Understanding Cloud Computing If you are wondering what is so special about the Cloud in Cloud Computing, here is an explanation- Traditionally, developers and architects used a picture of cloud to illustrate a remote resource connected via the web Janakiram & Associates 5

6 Eventually cloud became the logical connector between the local and remote resources on the Internet. Most of the developers get confused when they encounter the term Cloud Computing. According to them, their Web Services are already hosted on the Cloud and that can be potentially called as Cloud Services. While there is some truth in this argument, it is a not very accurate way of describing Cloud Computing. Let s look at Cloud Computing through the eyes of a developer. Think Web Services Most of the developers are familiar with Web Services. Web Services are based on a few simple concepts. Every Web Service accepts a request and returns a response (even if there is no explicit return value, a HTTP 200 OK return value is considered as a response). They are units of code that can be invoked over the web. Typically, Web Services accept one or more input parameters and invoke processing logic which will result in an output. Web Services are a part of web applications that run on a typical stack that has hardware, a Server OS, application development platform. For a while, think how you can expose every layer that is powering your web application as a Web Service. Web Services Stack 2012 Janakiram & Associates 6

7 Cloud OS Visualize a scenario where the hardware and the Operating System (OS) are exposed as a Web Service over the public Internet. Based on the principles of Web Services, we could send a request to this service along with a few parameters. Since the OS is expected to act as an interface to the CPU and the devices, we can potentially invoke a service that accepts a job that will be processed by the OS and the underlying hardware. Technically, this Web Service has just turned the OS + H/W combination into a Service. We can start consuming this service by submitting CPU intensive tasks to this new breed of Web Service. What do you call an OS that is exposed on the web as a service? May be a Cloud OS? We will answer this in the coming sections. Exposing the hardware and the OS as a Service Cloud FX Developers always develop and deploy their applications on the application development platforms. Some of the most popular application development platforms are.net and Java. In the last scenario, we have seen how the OS + H/W combination is offered as a service. Now, imagine a scenario where the application development platform is offered to you as a service. Through this, you will be able to develop and test your applications on a low end, inexpensive notebook PC but will able to submit the code to run on the most powerful hardware infrastructure. It is the same programming language, SDK and the runtime that runs on your development environment. If the 2012 Janakiram & Associates 7

8 hardware, OS, the language runtime and the SDK are offered to you as a service, what would you call this? A Cloud Platform or may be Cloud FX? We will address this in the next section. Exposing the Runtime + SDK as a Service Cloud Application Today, most of the traditional desktop applications like word processors and spreadsheet packages are available over the web. These new breed of applications just need a browser and offer high fidelity with the desktop software. This fundamentally changes the way software is deployed and licensed. You need not double click setup.exe to install an Office suite on your desktop. Just subscribe to the applications and the features that you need and only pay for what you use. This is almost equivalent to exposing the application as a service. These applications may be called as Cloud Applications. We will take a relook at this later. Web Application as a Service 2012 Janakiram & Associates 8

9 Welcome to the World of Services Infrastructure as a Service In the previous section we discussed the Cloud OS. All that the Cloud OS offers is the infrastructure services. You may choose to use REST API to manage this OS or use SSH or Remote Desktop console. Technically, when you are able to delegate a program to execute on a remote OS running on the Web, you are leveraging Infrastructure as a Service (IaaS). This is different from classic web hosting. Web hosting only hosts web pages and cannot execute code that needs low level access to the OS API. Web hosting cannot dynamically scale on demand. IaaS enables you to run your computing task on virtually unlimited number of machines. Remember that through IaaS, you have just moved a server running in your backyard into the Cloud. You are still responsible for managing, patching, securing and the health of the remote servers. Amazon EC2, Rackspace, IBM SmartCloud and OpenStack are examples of commercial IaaS offering. Cloud OS = Infrastructure as a Service Platform as a Service 2012 Janakiram & Associates 9

10 Platform as a Service or PaaS goes one level above the Cloud OS. Through this, developers can leverage a scalable platform to run their applications. The advantage of PaaS is that the developers need not worry about installing, maintaining, securing and patching the server. The PaaS provider takes the responsibility of the infrastructure and exposes the platform alone as a service. Through this, the developers can achieve higher level of scalability, reliability and availability of their applications. Microsoft Windows Azure, Google App Engine, Force.com, Heroku, Engine Yard and Cloud Foundry are some of the examples of PaaS. Cloud FX = Platform as a Service Software as a Service Software as a Service (SaaS) is a silent revolution in the world of traditional software products. With the availability of tablets and inexpensive netbooks combined with abundant bandwidth, most of the applications are moving to the Cloud to be offered as services. Consumers can now use inexpensive devices that are capable of connecting to the web to get their work done. This reduces the upfront investment in software and brings the Pay-as-you-go model. Google Apps, Salesforce.com and Microsoft Office365 are examples of SaaS Janakiram & Associates 10

11 Cloud App = Software as a Service What does Cloud Computing mean to you? IT Professionals and System Administrators For IT Professionals, Cloud Computing is all about consolidation and outsourcing the infrastructure. They are typically focused on the Infrastructure as a Service. IT Pros will move away from managing individual servers in their data centers to using a unified console to manage, track and monitor the health of the remote server instances running on the Cloud. IaaS is the focus area of IT Pros and system administrators Developers and Architects Platform as a Service is an offering meant for developers and architects. They need to design applications keeping the statelessness of the Cloud Janakiram & Associates 11

12 Architects should start thinking about the patterns that will make the applications seamlessly scale on-the-fly across hundreds of servers. PaaS is the focus area of developers and architects Consumers Consumers will experience the Cloud through a variety of applications that they will use in their day-to-day life. If you have ever used Google Docs, Dropbox or Microsoft Live Mesh, you have already leveraging the Cloud. Consumers will subscribe to Software as a Service offerings. SaaS delivers software through a subscription for the consumers 2012 Janakiram & Associates 12

13 Chapter 2 The Tenets of the Cloud The 4 Key Tenets I want to quickly recap the definition of Cloud Computing. It is all about outsourcing your infrastructure and applications to run on a remote resource. The remote resource phrase in the definition can be misleading and creates an illusion that running your web app on a server hosted abroad is Cloud Computing. So, what qualifies the remote resource to be called as the Cloud? Here are the 4 key capabilities that the Cloud Computing offers: Elasticity This is the most important attribute of the Cloud. You might start running your application on just a single server. But in no time, Cloud Computing enables you to scale your application to run on 100 s of servers. Once the traffic and usage of your application decreases, you can scale down to 10 s of servers. All this happens almost instantly and the best thing is your application and your customers don t even realize that. This dynamic capability of scaling up and scaling down is called Elasticity. Elasticity brings an illusion of Infinity. Though nothing is infinite in this world, your application can get any number of resources as it demands. This is the biggest promise of the Cloud. Now, think of web hosting. When you want to add another server to your web application, your hoster has to manually provision that for you. Adding additional servers and configuring the network topology introduces additional time lag that your business cannot afford. Most of the Cloud Computing vendors offer an 2012 Janakiram & Associates 13

14 intuitive way of manipulating your server configuration and topology. Elasticity is the single most important attribute of the Cloud. Elasticity of Cloud Computing Pay-By By-Use Elasticity and Pay-By-Use attributes go hand in hand. When you are scaling up your application by adding more resources, you know how much it is going to cost you. Pay-By-Use is a boon for the startups. As an entrepreneur, you got to balance your investment between human resources and IT resources. The biggest benefit of Pay-By-Use is that it reduces the CAPEX and turns your IT investment into OPEX. The analogy that I typically use is that of Cable or DTH TV subscription. During the season of Cricket World Cup or NBA, you would want to subscribe to the sports channels and unsubscribe that moment the event is over. With Pay-By-Use, you can subscribe and unsubscribe to the IT infrastructure based on your needs and you only pay for what you use. This is the most optimal way of spending your IT budget. Self Service When you are able to enjoy the capability of scaling up and scaling down and only pay for what you use, you never want to wait for someone in the datacenter to add an additional server to your application. Cloud can 2012 Janakiram & Associates 14

15 deliver its promise only when there is self service. Through this, you can control the resources all by yourself without an intermediary. When you add a new CPU core, a server instance or add extra storage, you do it by yourself by using the Console offered by the Cloud provider. This results in reduction in IT support and maintenance. Today most of the organizations have dedicated IT teams to provision a new machine, storage, collaboration portal and mailboxes as a part of on-boarding the new employees. Through Self Service, a fairly non-technical person can achieve these tasks and you don t need certified system administrators to do this. For example, when you sign up with Google Apps, it is very simple and intuitive to configure the mailboxes for the employees. With more and more applications moving the Cloud, Self Service becomes the preferred way of configuring and managing the IT infrastructure. AWS Management Console 2012 Janakiram & Associates 15

16 Microsoft Windows Azure Management Portal Programmability This is the critical attribute of the Cloud. The Cloud makes the developers extremely important. Developers are familiar with the concepts of multithreading where they spawn new threads to achieve scalability and the responsiveness of the application. They incorporate logic to create additional threads on demand. The programmability aspect of the Cloud adds a new dimension to the development. Developers can now create additional machines and add it to the applications on demand. They can treat the entire data center, servers and machines as an object model that be programmed. They can now do a For-Each loop on every server instance and decide what do with each instance. Amazon Web Services have the most mature API for programmatically controlling the Cloud based resources. Windows Azure supports the management API that lets developers programmatically deploy and manage Azure applications. By leveraging these APIs, developers are building applications to manage the infrastructure and some of these frontends run on ipad and Android devices. Now, imagine tapping on your mobile phone to add a dozen 2012 Janakiram & Associates 16

17 servers to your application. Thanks to the Cloud! Developers are important more than ever! AWS SDK for.net Visual Studio AWS Plug-in for Eclipse 2012 Janakiram & Associates 17

18 iphone App to manage AWS So, let s summarize what we just discussed. Cloud Computing has 4 key tenets 1) Elasticity, 2) Pay-By-Use, 3) Self Service, and 4) Programmability. Hosting vs. Cloud Computing Revisiting the on-going debate of hosting vs. Cloud Computing, let s see what attributes hosting model exposes. Hosting can never meet the promise of elasticity. Even if it does, it won t match the economics of the Cloud. Hosting does offer some level of Self Service but not to an extent of manipulating the server configuration on the fly! Pay-By-Use attribute is emulated by some hosting companies. But, it is not a norm in the hosting business. Programmability is too expensive to be supported by hosters as they cannot invest in the SDK and tools to manage the infrastructure. So, it is clearly evident that hosting is not the same as Cloud Computing. Having understood the key attributes of the Cloud, you might start wondering how you can bring these capabilities to your data center in the enterprise. The reality is that these capabilities can be applied to your data center and officially that is called as the Private Cloud. It is time for us to discuss 2012 Janakiram & Associates 18

19 various implementations of the Cloud. We will look at 4 different mechanisms the way Cloud can be implemented. Hosting vs. the Cloud The 4 Implementations of the Cloud Public Cloud This is the most popular incarnation of the Cloud. Many businesses and individuals realize Cloud through the Public Cloud implementation. It needs a huge investment and only well established companies with deep pockets like Microsoft, Amazon and Google can afford to set them up. Public Cloud is implemented on thousands of servers running across hundreds of data centers deployed across tens of locations around the world. The best thing about Public Cloud is that the customers can choose a location for his application to be deployed. This will reduce the latency when the consumers access the application. For example, a London based business can choose to deploy their app at the Europe data center and an American company prefers a data center in North America. With the geographical spread, Public Clouds like Amazon Web Services, Rackspace and Microsoft Windows Azure also offer Content Delivery Network (CDN) features. Through this, static content will be automatically cached across all the data centers around the globe thus increasing the scalability of the application and offering better user experience to end-users Janakiram & Associates 19

20 Public Cloud Private Cloud Simply put, Private Clouds are normal data centers within an enterprise with all the 4 attributes of the Cloud Elasticity, Self Service, Pay-By-Use and Programmability. By setting up a Private Cloud, enterprises can consolidate their IT infrastructure. They will need fewer IT staff to manage the data center. They will also realize reduced power bills because of the low electricity consumption and lesser cooling equipment needs. Private Cloud empowers employees within an organization through Self Service of their IT needs. It becomes easy to provision new machines and quickly assign them to project teams. Private Cloud borrows some of the best practices of Public Cloud but limited to an organizational boundary. Private Cloud can be setup using a variety of offerings from vmware, Microsoft, IBM, SUN and others. There are also some of the Open Source implementations like Eucalyptus and OpenStack. We will discuss more of Private Cloud in the coming episodes Janakiram & Associates 20

21 Private Cloud Hybrid Cloud There are scenarios where you need a combination of Private Cloud and Public Cloud. Due to the regulations and compliance issues in few countries, sensitive data like citizen information, patient medical history, and financial transactions cannot be stored in servers that physically not located within the political boundaries of a country. In some scenarios, the enterprise customers want to get best of the both worlds by logically connecting their Private Cloud and the Public Cloud. Through this, they can offer seamless scalability by moving some of the on-premise and Private Cloud based applications to the Public Cloud. Security plays a critical role in connecting the Private Cloud to the Public Cloud. Realizing its importance, Amazon Web Services offers Virtual Private Cloud (VPC) that securely bridges Private Cloud and Amazon Web Services. It is a way of extending your infrastructure beyond the organizational boundary and the firewall in a secure way. Windows Azure AppFabric brings the concept of Hybrid Cloud to Microsoft s enterprise customers Janakiram & Associates 21

22 Hybrid Cloud Community Cloud Community Cloud is implemented when a set of businesses have a similar requirement and share the same context. This would be made available to a set of select organizations. For example, the Federal government in US may decide to setup a government specific Community Cloud that can leveraged by all the states. Through this, individual local bodies like state governments will be freed from investing, maintaining and managing their local data centers. Similarly, the Reserve Bank of India (RBI) or Unique Identification Authority of India (UIDAI) may setup a Community Cloud for all the financial institutions that share common goals and requirements. So, a Community Cloud is a sort of Private Cloud but goes beyond just one organization. Community Cloud 2012 Janakiram & Associates 22

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24 Chapter 3 The Anatomy of the Cloud Introduction to Virtualization Virtualization is abstracting the hardware to run virtual instances of multiple guest operating systems on a single host operating system. You can see Virtualization in action by installing Microsoft Virtual PC, VMware Player or Oracle VirtualBox. These are desktop virtualization solutions that let you install and run an OS within the host OS. The virtualized guest OS images are called Virtual Machines. The benefit of virtualization is realized more on the servers than on the desktops. Server Virtualization There are many reasons for running Virtualization on the servers running in a traditional data center. Here are a few: Mean Time To Restore It is far more flexible and faster to restore a failed web server, app server or a database server that is running as a virtualized instance. Since these instances are physical files on the hard disk for the host operating system, just copying over a replica of the failed server image is faster than restoring a failed physical server. Administrators can maintain multiple versions of the 2012 Janakiram & Associates 24

25 VMs that come handy during the restoration. The best thing about this is that the whole copy and restore process can be automated as a part of disaster recovery plan. Maximizing the server utilization It is very common that certain servers in the data center are less utilized while some servers are maxed out. Through virtualization, the load can be evenly spread across all the servers. There are management software offerings that will automatically move VMs to idle servers to dynamically manage the load across the data center. Reduction in maintenance cost Virtualization has a direct impact on the bottom line. First, by consolidating the data center to run on fewer but powerful servers, there is a significant cost reduction. The power consumed by the data center and the maintenance cost of the cooling equipment comes down drastically. The other problem that virtualization solves is the migration of servers. When the hardware reaches the end of the lifecycle, the physical servers need to be replaced. Backing up and restoring the data and the installation of software on a production server is very complex and expensive. Virtualization makes this process extremely simple and cost effective. The physical servers will be replaced and the VMs just get restarted without any change in the configuration. This has a significant impact on the IT budgets. Efficient management All major virtualization software have a centralized console to manage, maintain, track and monitor the health of physical servers and the VMs running on these servers. Because of the simplicity and the dynamic capabilities, IT administrators will spend less time in managing the infrastructure. This results in better management and cost savings for the company. Virtualization on the Server Let s understand more about the server virtualization. Typically the OS is designed to act as an interface between the applications and the hardware. It is not specifically designed to run the guest OS instances on top of it Janakiram & Associates 25

26 Ap p Ap p Ap p Ap p Ap p Ap p Operating System Hardware An OS Managing the Applications In fact, in the server virtualization scenario, the host OS is not very significant. It is just confined to booting up and running the VMs. Given the fact that the OS is not ideal for running multiple VMs and has a little role to play, there is a new breed of software called Hypervisor that takes over the OS. Hypervisor is an efficient Virtual Machine Manager (VMM) that is designed from the ground up to run multiple high performant VMs. So, a Hypervisor is to VMs what an OS is to processes. VM VM VM VM VM VM Hypervisor Hardware A Hypervisor Managing the Virtual Machines A Hypervisor can potentially replace the OS and can even boot directly from a VM. This is called bare metal approach to virtualization. These Hypervisors have low footprint of few megabytes (vmware ESXi is just 32MB in size!) and have an embedded OS with them. Hypervisors are assisted by the hardware virtualization features built into the latest Intel and AMD CPUs. This 2012 Janakiram & Associates 26

27 Figure 3. Hypervisor manages the VMs combination of hardware and Hypervisor turns the server into a lean and mean machine to host multiple VMs. The VM that is used by the Hypervisor to boot as a host is called a para-virtualized VM. This concept makes virtualization absolutely powerful. Imagine a server booting in few seconds and the required para-virtualized (host) VM gets copied over a gigabit Ethernet to run multiple guest VMs. This enables the datacenter to be very dynamic and agile. The Hypervisor can be controlled by a central console and can be instructed about the host VM to boot and the guest VMs to be run on it. App App App App App App VM VM VM Paravirtualized VM Hypervisor Hardware A look at the Hypervisor market Citrix XenServer This product is based on the proven, open source Hypervisor called Xen. Xen s paravirtualization technology is widely acknowledged as the fastest and most secure virtualization software in the industry and it is enhanced by taking full advantage of the latest Intel VT and AMD-V hardware virtualization assist capabilities. This product is free and can be downloaded from Citrix.com. VMware ESXi 2012 Janakiram & Associates 27

28 This product is another bare metal Hypervisor from the virtualization leader, VMware. This is one of the best Hypervisors with just 32MB footprint. ESXi ships with Direct Console User Interface (DCUI) that provides basic UI required for administering and managing the Hypervisor. Through its standard Common Information Model (CIM) system, it also exposes the APIs to control the infrastructure. Microsoft Hyper-V Server This is a free Hypervisor from Microsoft based on the same Hypervisor that ships with Microsoft Windows Server Hyper-V edition. This is best suited for Virtual Desktop Infrastructure (VDI) because of its compatibility with Windows Vista and Windows 7. Hyper-V does not have any local GUI but can be managed from System Center Virtual Machine Manager (SCVMM). Virtualization and the Cloud The architecture that we discussed forms the heart and soul of Cloud Computing. Here is how Elasticity We know that the key attribute of the Cloud is Elasticity, which is the ability to scale up and scale down on the fly. This capability is achieved only through virtualization. Scaling up is technically adding more server VMs to an application and scaling down is detaching the VMs from the application. Self Service The next attribute is Self Service. The Hypervisor comes with an API and the required agents to manage it remotely. This functionality can surface through the Self Service portals that the Cloud vendor offers. So, when you move a slider to increase the number of servers in your web tier, you are essentially talking to the Hypervisor to action that request. Pay-By By-Use 2012 Janakiram & Associates 28