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- Herausgeber: John Wiley & Sons
- Kategorie: Wissenschaft und neue Technologien
- Sprache: Englisch
An essential resource for implementing and managing a cloud infrastructure in Azure Serving as a critical resource for anyone responsible for strategizing, architecting, implementing or managing a cloud infrastructure, this book helps you understand what is hybrid IT and how it's applicable (and inevitable) in today's world of emerging cloud. The team of authors focus on the Microsoft concept of a private/public cloud, deploying a private cloud fabric, deploying services, and building a private cloud, as well as integrating it with Microsoft's public cloud to create a cross-premises or public cloud. * Looks at why hybrid IT is important to a business and what benefits a business can expect by adopting hybrid cloud * Examines a cloud management platform and discusses why it is necessary * Walks you through the different kinds of solutions for IT problems that may arise * Places a focus on considerations for ensuring resiliency, availability, and scalability when designing hybrid solutions to prevent system failure and data loss * Covers optimizing the performance of the hybrid cloud as well as using tools that help you monitor and manage the performance of the hybrid cloud Windows Azure Hybrid Cloud helps you gain a better understanding of the hybrid IT environments, why those clouds should be implemented, and how they impact business.
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Seitenzahl: 384
Veröffentlichungsjahr: 2013
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Contents
Introduction to the Windows Azure Book Series
Introduction to Windows Azure Hybrid Cloud
Chapter 1: What Is Hybrid IT?
The Thing They Call the “Cloud”
Cloud Service Models
What are the Trends that You Should Watch?
What are the Characteristics of a Cloud?
Private Clouds
Hybrid Cloud
Summary
Chapter 2: Why is the Hybrid Cloud Important to My Business?
Everyone Else is Doing it
Cutting Costs for the Short Term
Outsourcing Data Security Responsibilities
A Case for Hybrid Cloud
Summary
Chapter 3: Project Planning
Envisioning and Scoping
Mapping Technical Solutions to Business Objectives (Building Business Requirements)
Formulating Technical Requirements
Prioritizing Your Objectives
Building the Solution
Summary
Chapter 4: What You Need to Know About Windows Azure As a Platform
Execution Models
Data Management
Messaging and Integration Components
Supporting Services
Software Development Kits
Summary
Chapter 5: Private Cloud Components and Services That Help to Build Hybrid Clouds
The Cloud Management Platform
Integrating System Center and Windows Azure
Networking
Identity Management
Summary
Chapter 6: Hybrid Options in Windows Azure
On-Premises Service Integrated with Cloud Service
Cloud Service Integrated with On-Premises Service
Cloud Bursting, or Batching at Scale
Development and Test Cloud Infrastructure
Windows Azure as a Disaster Recovery (DR) Site
Service Bus as an Integration Hub
Enabling Modern Applications
Virtual Desktops in Windows Azure
Summary
Chapter 7: Designing for Resiliency and Scalability
Building Resilient Solutions
Designing for Business Continuity
Planning Hybrid Cloud Site Disaster Recovery
Designing Scalable Hybrid Cloud Solutions
Summary
Chapter 8: Optimizing for Performance
Cloud Application Performance Fundamentals
Optimizing Network Throughput and Latency
Summary
Chapter 9: Monitoring and Management for Successful Operations
Change Is the New Normal
Monitoring the Hybrid Cloud
Unified Management
Summary
Chapter 10: Final Hybrid Cloud Considerations
How Do I Execute My Hybrid Cloud Initiative?
Embracing Continual Improvement
When Is It Time to Jump Onboard?
The Time is Now — the Tipping Point
Summary
INTRODUCTION TO THE WINDOWS AZURE BOOK SERIES
It has been fascinating watching the maturation of Windows Azure since its introduction in 2008. When it was announced, Azure was touted as being Microsoft’s “new operating system.” And at that level, it has not really lived up to its billing. However, if you consider Azure to be a collection of platforms and tools that allow you to cloud-enable your corporation’s applications and infrastructure, well, now you’re on the right track.
And, as it turns out, a collection of co-operating tools and services is the best way to think of Azure. The different components that comprise Azure become building blocks that allow you to construct an environment to suit your needs. Want to be able to host a simple Website? Well, then Azure Web Sites fits the bill. Want to move some of your infrastructure to the cloud while leaving other systems on premise? Azure Virtual Networking gives you the capability to extend your corporate domain to include machines hosted in Azure. Almost without exception, each twist and turn in your infrastructure roadmap can take advantage of the building blocks that make up Windows Azure.
A single book covering everything that encompasses Azure would be huge. And because of the breadth of components in Azure, such a book is likely to contain information that you are not necessarily interested in. For this reason, the Windows Azure series from Wrox takes the same “building block” approach that Azure does. Each book in the series drills deeply into one technology. If you want to learn everything you need to work with a particular technology, then you could not do better than to pick up the book for that topic. But you don’t have to dig through 2,000 pages to find the 120 pages that matter to you. Each book stands on its own. You can pick up the books for the topics you are care about and know that’s all that you will get. And you can leave the other books until desire or circumstance makes them of interest to you.
So enjoy this book. It will give you the information you need to put Windows Azure to use for you. But as you continue to look to other Azure components to add to your infrastructure, don’t forget to check out the other books in the series to see what topics might be helpful. The books in the series are:
Windows Azure and ASP.NET MVC Migration
by Benjamin Perkins, Senior Support Escalation Engineer, Microsoft
Windows Azure Mobile Services
by Bruce Johnson, MVP, Partner, ObjectSharp Consulting
Windows Azure Web Sites
by James Chambers, Product & Community Development Manager, LogiSense
Windows Azure Data Storage
by Simon Hart, Software Architect, Microsoft
Windows Azure Hybrid Cloud
by Danny Garber, Windows Azure Solution Architect, Microsoft; Jamal Malik, Business Solution Architect; and Adam Fazio, Solution Architect, Microsoft
Each one of these books was written with the same thought in mind: to provide deep knowledge of that one topic. As you go further into Azure, you can pick and choose what makes sense for you from the other books that are available. Constructing your knowledge using these books is like building blocks, which is just in the same manner that Azure was designed.
Bruce Johnson
Azure Series Book Editor
INTRODUCTION TOWINDOWS AZURE HYBRID CLOUD
The three authors of Windows Azure Hybrid Cloud, Adam, Danny and Jamal, belong to special groups within Microsoft. Adam and Jamal work for the Global Datacenter and Private Cloud Center of Excellence (CoE), and Danny is part of the Global Azure Modern Apps CoE. When Microsoft looks to develop its capabilities within a specific area they stand-up CoE’s to blaze the trail and train other resources within that area (not unlike other large organizations).
Their charter is simple. It is to Evangelize and Grow Microsoft’s Private and Public Cloud Strategy. It’s a fairly broad charter; however, it is that way for a reason. It is stated that way because there are multiple points of entry to a Microsoft Cloud solution and they execute against this charter through three key areas:
Solution and Opportunity Identification (Pre-Sales)
Cloud Solution Development (IP – intellectual property)
Internal and External Field Enablement (Readiness)
Jamal’s area of focus is working with business decision makers (CIO’s mostly) and understanding the motivations and business strategies for large (typically Fortune 1000) organizations and identifying opportunities or solutions which Microsoft can assist in enabling them to achieve their strategic business goals and imperatives. If it isn’t already obvious, there is an incredible amount of effort that goes into analyzing and understanding a Fortune 1000 Company’s business strategy (more on that later). In any event, when Jamal has these initial conversations he then looks to pass off these private and public cloud opportunities to the Datacenter and Azure Modern Apps CoE’s, respectively. Increasingly over the last year Jamal has come across opportunities where organizations would actually benefit more from Hybrid Cloud Solutions (a mixture of public and private cloud technologies). That is really how the idea of this book was born. Microsoft knows and understands that Hybrid Cloud Solutions are the path to the future. Their teams are continuously encouraged by management to collaborate more and find different ways to work together. So here they are.
Adam, Danny and Jamal are really excited to put this book together for the benefit of organizations everywhere. They wholeheartedly believe that the future of Information Technology is smack dab in the middle of this phenomenon called Cloud and are happy to do whatever they can to demystify or bring clarity to organizations that are looking to make this journey. This book is the outcome of months’ worth of collaboration between these three and they can honestly say it was much easier than they thought it was going to be. Working together was such a motivator within itself and they feel incredibly fortunate to be given the opportunity to be at the very cusp of a brand new revolution that is taking place within the IT world and are even happier to share the insights they have gained while operating in this space with you.
As you thumb through the pages (or click or swipe for that matter) of Windows Azure Hybrid Cloud remember that this is just the first phase of your organization’s journey to Hybrid Cloud Solutions. As you work through this exercise within your company you will learn that there are unique characteristics to your organization (whether people, process, or technology). The purpose of this book is to reduce or account for the risks associated with migrating towards a Hybrid Cloud Solution; however, it is unrealistic to assume that all risks can be accounted for completely. Frankly, we must balance the amount of planning that we as business and IT decision makers do in preparing for initiatives such as these. At some point we must decide and firmly set in our minds that this will happen, and we will move forward. Otherwise we get caught up in “Analysis Paralysis” as it is called in the consulting world. The best thing to do in order to avoid Analysis Paralysis is to set a deadline with go\no go criteria. We will discuss this and various other methods, approaches, and strategies in this book; however, bear in mind that you either write your own organization’s destiny, or it will be written for you. Thank you again for reading this book. Adam, Danny and Jamal wish you the best of luck on your journey towards a Hybrid Cloud!
WHO THIS BOOK IS FOR
Although this book can be read by just about any IT Professional (Architects, Sys Admins, Support Staff, etc.) it is primarily focused on addressing the concerns and needs of Business and Technical Decision Makers. We call out specifically CIO’s, SVP of Infrastructure, and VP’s of Operations and Engineering. We specifically targeted Business and Technical Decision Makers because frankly, many of the changes an organization must make in order to realize the benefits that can be gained through adopting cloud solutions require some form of organizational or behavioral change. These changes typically require executive sponsorship and will have an impact on both business and IT operational activities for the organization.
This doesn’t mean, however, that other roles within a business cannot benefit from this book (far from it). We provide guidance on how to build business cases, gain executive sponsorship, and pinpoint the changes that will be needed by the business to adopt a hybrid cloud solution. Therefore, we highly recommend that a wide array of individuals read this book. Regardless of your role, you will gain deep insight as to what the proper motivation should be to move to a cloud solution and be provided with the proper guidance to ensure that the approach used to discern whether a cloud solution is a right fit, as well as architecting, designing, and operating the cloud solution is done in a consistent and standardized manner.
WHAT THIS BOOK COVERS
The chapters in this book address the aspects of moving your organizations to cloud solutions in a systematic and pragmatic approach that will look to reduce the risk and account for the different dimensions in which making this transition will have on your business and organization. We will cover all three Cloud Service models (IaaS, PaaS and SaaS), provide details to help you decide which models are most appropriate for your organization, and also provide guidance that will aid not only in the transitioning of your organizations to adopting cloud solutions but also provide a very structured approach to operating and maintaining this new solution as well.
As a note, we will mainly focus on providing guidance to organizations that wish to leverage Hybrid Cloud solutions. It is of our viewpoint that pure Private Cloud solutions (although applicable to many organizations) are most beneficial to organizations who wish to provide cloud services to other businesses (i.e. Hosters, Solution Integrators, etc.). The reason for this is because the up-front investment needed to plan, build and design an on-premises cloud solution is fairly substantial and could possibly take many organizations over a decade to fully realize their return on investment just from a cost perspective. Does this mean that organizations can’t realize the benefit of a truly Dynamic Datacenter? Of course not. We would suggest however that organizations look to leverage cloud capabilities offered by other more established Service Providers before turning to a Private Cloud to satisfy those needs. This doesn’t mean, however, that some organizations (regardless of their size) will also need a Pure Private Cloud solution. Adopting a Private Cloud is an entirely another subject altogether, and therefore the focus of this book will be providing guidance to adopting Hybrid Cloud solutions and offerings (regardless of organization composition and size).
HOW THIS BOOK IS STRUCTURED
Although we have written this book to be read linearly you may find that certain portions of this book may seem more interesting or relevant to you than others (and that is perfectly OK). We suggest that regardless of your background you should try to read every chapter. This is because it will put you on equal footing with other resources in your organization regardless of their background on why, how, and when to adopt a Hybrid Cloud Solution. With that being said we would also like to provide some guidance on what chapters you should pay particular attention to based on your role:
C-Level Executives
Chapter 1
Chapter 2
Chapter 10
Technical Decision Makers
Chapter 1
Chapter 2
Chapter 3
Chapter 10
IT Architects
Entire Book
System Administrators
Chapter 1
Chapter 5
Chapter 8
Chapter 9
Chapter 10
This is not an exhaustive list of roles and suggested chapters; however, you get the idea that the beginning few chapters really cover the motivation and reasoning to adopting a Hybrid Cloud Solution, and Chapter 4 onward is focused more on the “what” and “how” of achieving it.
Chapter 1: What Is Hybrid IT?
Discover an overview of the motivations, deployment models, and characteristics of a Cloud Solution. We set expectations around what are some of the benefits an organization can look to achieve through adopting cloud and also cover what are some un-realistic expectations as well.
Chapter 2: Why Is the Hybrid Cloud Important to My Business
Learn how to properly define and state the proposed benefits that adopting a Hybrid Cloud Solution will provide, as well as the business and organizational change that must take place in order to realize those benefits.
Chapter 3: Project Planning
Understand the approach, scope, and activities related to architecting, designing, and building a Hybrid Cloud Solution.
Chapter 4: What You Need to Know About Azure As a Platform
Take a closer look at the capabilities and features available through the Microsoft Azure Platform. Azure offers more than just Platform as a Service, and now provides features such as Infrastructure as a Service, Media Services, and SQL as a Service.
Chapter 5: Private Cloud Components and Services That Help to Build Hybrid Clouds
Learn the on-premise capabilities that will be needed in order to properly deploy a Hybrid Cloud Solution. This chapter covers not only the components available through Microsoft System Center but also covers networking and identity management topics.
Chapter 6: Hybrid Options in Windows Azure
Distinguish the different methods, scenarios, and approaches that can be used in building a Hybrid Cloud Solution.
Chapter 7: Designing for Resiliency and Scalability
After pulling the capabilities of System Center and Azure together, we are now able to offer guidance on building workloads that are resilient, highly available, and elastic across both Private and Public Clouds.
Chapter 8: Optimizing for Performance
Once workloads have been defined, learn about application architecture performance fundamentals, and storage and networking performance considerations for a Hybrid Cloud Service model.
Chapter 9: Monitoring and Management for Successful Operations
See that as the Workloads and Applications begin moving into deployment, we cover the operational and management principals that govern a hybrid cloud environment, including people and process implications.
Chapter 10: Final Hybrid Cloud Considerations
You are about to pull the trigger on the Hybrid Cloud Solution. What are a few things to think about not only from a technical perspective but from an organizational change perspective as well? Your journey to the cloud will be an on-going one, and we will talk through the process of easing your organization to leverage cloud solutions in a much more open fashion, as well as discuss techniques to handle objections, concerns, and other roadblocks that may arise during the process of adopting Hybrid Cloud.
CONVENTIONS
To help you get the most from the text and keep track of what’s happening, we’ve used a number of conventions throughout the book.
As for styles in the text:
* We
highlight
new terms and important words when we introduce them.
* We show keyboard strokes like this: Ctrl+A.
* We show filenames, URLs, and code within the text like so:
persistence.properties
.
* We present code in two different ways:
We use a monofont type with no highlighting for most code examples.
We use bold to emphasize code that’s particularly important in the present context
.
ERRATA
We make every effort to ensure that there are no errors in the text or in the code. However, no one is perfect, and mistakes do occur. If you find an error in one of our books, such as a spelling mistake or a faulty piece of code, we would be very grateful for your feedback. By sending in errata you may save another reader hours of frustration and at the same time you will be helping us provide even higher quality information.
To find the errata page for this book, go to www.wrox.com and locate the title using the Search box or one of the title lists. Then, on the book details page, click the Book Errata link. On this page you can view all errata that has been submitted for this book and posted by Wrox editors. A complete book list, including links to each book’s errata, is also available at www.wrox.com/misc-pages/booklist.shtml.
If you don’t spot “your” error on the Book Errata page, go to www.wrox.com/contact/techsupport.shtml and complete the form there to send us the error you have found. We’ll check the information and, if appropriate, post a message to the book’s errata page and fix the problem in subsequent editions of the book.
P2P.WROX.COM
For author and peer discussion, join the P2P forums at p2p.wrox.com. The forums are a Web-based system for you to post messages relating to Wrox books and related technologies and interact with other readers and technology users. The forums offer a subscription feature to e-mail you topics of interest of your choosing when new posts are made to the forums. Wrox authors, editors, other industry experts, and your fellow readers are present on these forums.
At http://p2p.wrox.com you will find a number of different forums that will help you not only as you read this book, but also as you develop your own applications. To join the forums, just follow these steps:
Once you join, you can post new messages and respond to messages other users post. You can read messages at any time on the web. If you would like to have new messages from a particular forum e-mailed to you, click the Subscribe to this Forum icon by the forum name in the forum listing.
For more information about how to use the Wrox P2P, be sure to read the P2P FAQs for answers to questions about how the forum software works as well as many common questions specific to P2P and Wrox books. To read the FAQs, click the FAQ link on any P2P page.
Chapter 1
What Is Hybrid IT?
IN THIS CHAPTER:
Understanding the cloud service models
Examining key cloud trends
Learning why you should and shouldn’t adopt a cloud solution
Forget for one moment all of the rhetoric you hear today from analysts and researchers about the growth and increased adoption of this thing they call the cloud. Focus instead on you: the individual, the business owner, CIO, IT director, IT professional, or consultant. In particular, focus on some of the challenges you face today. Chances are good you are responsible for the health of your business’s IT environment (either directly or indirectly). Maybe you are even accountable for the performance or achievement of the earnings your business is expected to produce. Chances are you are constantly trying to balance day-to-day operational activities with projects or special initiatives.
THE THING THEY CALL THE “CLOUD”
So in your situation, the question you must ask yourself is this: “Will leveraging cloud solutions really assist my organization in achieving its business plans and objectives?” Although it seems obvious, that answer (interestingly enough) is a resounding no. There is no shortage of traditional solutions that provide capabilities to help your organization achieve its business goals. In fact, these solutions have been doing just that for quite some time now. Just because cloud solutions are the new hype, it doesn’t leave all existing (or traditional) solutions irrelevant.
That said, it’s important to consider what will happen if you don’t take advantage of some of these cloud solutions and your competitors do. Will they find new levels of efficiency in their organization or streamline their operational processes to a point where they now have an advantage over your organization in terms of agility, control, and execution? The answer here is a resounding YES. The benefits that cloud solutions bring to an organization are very apparent. The impact and provided benefits in terms of resilience and reliability (due to the expertise and economies of scale achieved by service providers) and potentially shifted cost structures will easily outweigh the cost\capability battle when compared to similar functions provided by your traditional (on-premises) technologies and solutions.
So, what is all this excitement about the cloud anyway? In this chapter we’ll try to share some insight as to why so many organizations are looking to cloud solutions to transform their organizations. First, however, we want to make sure that we are all talking about the same thing. A plethora of solutions and offerings in the market claim to be cloud-centric, or something within that realm, so we will first explore the anatomy of a cloud to help you differentiate between solutions that actually provide cloud capabilities and those that do not.
CLOUD SERVICE MODELS
In this section, we want to explain the three following cloud service models:
Infrastructure-as-a-Service (IaaS)
Platform-as-a-Service (PaaS)
Software-as-a-Service (SaaS)
We’ll begin with the analogy that everyone can understand and relate to — transportation. If you are like most, two of your main requirements of transportation are as follows:
It must be available to you whenever you need it.
It must take you from point A to point B.
So, with those requirements in mind, you drove to the dealership and bought a new car. Congratulations! Now, assuming you know how to drive, you can drive it anywhere, anytime, and for as long as you can, as long as you stop for rest and refueling your gas tank.
At the same time, you must take care of your car so that it stays usable and operational. And if you think of your personal vehicle as the investment you have made for many years to come, you are wrong. The very minute that you drive a new car off a dealer’s lot, it loses value. On average, cars depreciate about $3,000 annually. So does the hardware you bought for your datacenter.
Here comes the first comparison. Think of the traditional IT and the hardware (servers, network switches, hubs, etc.) as if it were your own car you bought, you drive, and you take care of (maintenance, service checks, etc.). If you draw the parallel line, you could quickly appreciate the common pattern of having full control over where it goes and when, and the depreciation of value over the time (see Figure 1-1).
FIGURE 1-1
Infrastructure-as-a-Service — The Leasing Option
Now, consider the car leasing option. There are a few striking key differentiators from the previous model — your own car (a.k.a. traditional IT datacenter). Those differences can be outlined as:
You pay monthly fees during the entire lease period, which sum in total to 50-60 percent of the new car’s manufacture price tag.
You can still drive whenever you want and wherever you wish, but with imposed mileage limits (for example: a lease contracts may have 36 K miles maximum per 36 months of lease).
There’s also a limitation of cars/models types that are available for lease.
You still have to take care of your leased car as if it were your own (service maintenance, refueling, changing the tires, etc.), but because you don’t own it you can’t modify it in any way.
And that’s exactly, or almost exactly, what you are going to get when you “lease” the Infrastructure-as-a-Service (IaaS) from the public cloud provider (the “dealership”). This is equivalent to leasing a virtual server on which the tenant can install their own operating system and administer the server themselves. Like when you lease a car, in the case of leasing VMs from your public cloud service provider you will observe the following “+” and “-” that may affect your business decision on when to choose what cloud service model:
Pros:
You can use pre-installed VMs containing some of the most common software packages installed and ready for you to configure per your business needs. Windows Azure IaaS includes a standardized VM Image Gallery for consistent workload deployment and hosting. The VMs you can find in this gallery are available for “pick-up” to serve as the starting point (in many cases it puts you on the accelerated path) for your IaaS deployment environment. Note that only Microsoft Windows Azure IaaS cloud services offers the Image Gallery at this moment. No other cloud vendors currently have that. Think about the pre-installed navigation and sound systems in your leased car.
You pay only for the time you use your VM in IaaS. Note that the Azure VMs must be shut down (turned off) in order for billing charges to stop. More on Azure VMs later.
Can easily scale-up and scale-down whenever you need it to.
Cons:
Have the limited choice of what guest OSs are currently supported by cloud vendors. For example, you can’t bring your own VM containing Windows Server 2003 32-bit OS.
Have limitation on the VM formats supported by a cloud provider’s IaaS platform. For instance, Microsoft doesn’t support VMWare VM images on their Windows Azure IaaS, while Amazon only supports its own proprietary VM format forcing customers to convert their original on-premises VM formats into Amazon’s format.
Have restrictions imposed on you by a cloud provider on what software licenses you can bring to the public cloud. For example, Oracle DB isn’t supported on Windows Azure IaaS VMs due to the licensing restrictions imposed by Oracle.
So far so good, right? Now it’s time to look at the other two popular public cloud hosting models: Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS).
Platform-as-a-Service — The Rental Option
PaaS is analogous to another transportation option: a rental car. In this case, you need to go from point A to point B for the T duration (in most cases from 1 to 7 days, sometimes longer). Does it make sense for you to go and buy a new car? No, and we proved it with our car depreciation analysis. Does it make sense to lease a car for a short period of time, say, in some place you came for vacationing or for a business? Absolutely not! First of all, no one will lease you a car for such a short period of time, and secondly — and most importantly — you wouldn’t want to pay heavy costs associated with a leased car (down payment, residual depreciation fees, dealership, and car delivery fees). It’s not worth it.
Thankfully, rental car agencies allow you, for a nominal fee, to use a rental car per day, to drive wherever you want and whenever you want without worrying about the car maintenance, tires, and sometimes even filling the gas tank. It’s all included in the rental price. “It’s all included” is the key phrase. Because, when you draw the parallel line from the car analogy back to the public cloud, you can see that PaaS has most of the features owned or leased to you by a cloud vendor included in its hosting model. In other words, when you “rent” a piece of cloud — that is, deploy your application to the PaaS flavor of the public cloud — you will observe the following:
Pros:
Pay as you go, or pre-pay for the specific period of time/consumption.
Use the cloud only when you need it.
Have no need to worry about infrastructure maintenance, OS, and security upgrades, patches, networking, load balancing.
Can easily scale-up and scale-down whenever you need it to.
Cons:
Have the limited choice in what you can rent (read: “deploy”).
Have restrictions imposed on you by a cloud provider on what you can bring to the public cloud and in what capacity.
By now, you should have if not a completely clear picture, at least a partially cloudy picture of how an IaaS cloud model is different from a PaaS cloud model. Both models have their own Pros and Cons and the absolute right to co-exist and/or be your preferable choice for your business cloud solution.
Now, let’s review the third cloud hosting model, SaaS, while comparing it to the other two you have just finished reading about.
Software-as-a-Service — The Public Transportation Option
Finally, what transportation options do you have when you don’t know how to operate the vehicle or simply don’t want to? You choose public transportation. To use public transportation you buy a ticket, day pass, monthly pass, or Oyster card (if you’re in London), and use it every time you get onboard the train, bus, subway, or airplane.
It still can take you from point A to point B, but cannot take you to point C if the bus’s route doesn’t go there. At the same time you don’t have to know how to drive the bus, and of course, you have no maintenance headaches, need to fill the gas, or requirement to be always alert when operating the vehicle. Once again, drawing the parallel line from transportation analogy back to the public cloud, you can see the same pattern realized in the Software-as-a-Service (SaaS) public cloud deployment model. As you have tradeoffs when you use public transportation, running the software package such as Office, Mail Exchange, SharePoint, CRM, etc., on someone’s else cloud without investing in infrastructure hardware, software licenses, and operational maintenance cost has its obvious perks as well as some disadvantages:
Pros:
You pay on a per-user basis.
No software licenses are required.
You can easily scale-up and scale-down whenever you need to.
No skills to run and operate third-party software are required.
The system is always highly available.
SLAs are guaranteed.
Cons:
SaaS is typically a multi-tenant, shareable environment, where you share physical resources with others tenants (customers). Theoretically, if someone messes up the physical ecosystem you happen to share, you and your customers are impacted as well.
There is a limited list of SaaS packages available today.
You can always make some limited configuration changes in the product you “rent” as part of your SaaS subscription, but rarely can you customize or tailor to your own business needs.
By now, you should have made the obvious connection in the parallel patterns we tried to draw here through the transportation analogy, and we hope you can see the differences as well as the pros and cons of each public cloud hosting model. We believe that drawing parallel lines between the cloud service models and the various options you have when choosing a specific type of transport whether it is your own vehicle, a lease car, rental car, or public transportation, would help you better understand the common traits and differences that exist between these three cloud service models. However, by providing such an analogy we certainly do not aim to give you a recipe or instructions on how to choose between the cloud service models. Obviously, whatever reasons that affect your decision in choosing between lease, rental, or public transportation cannot be and shouldn’t be applied to the cloud service models decision making process. Our aim was merely to give you the perspective on various factors that can be applied for each cloud service model, and which, to some degree, can be explained in more accessible, plain English understood by virtually every reader of this book.
To clarify the differences each public cloud hosting model has even more, take a look at Figure 1-2:
FIGURE 1-2
Whether you are buying our public cloud computing story or not, enterprise application developers are finding the self-service, pay-as-you-go, instant deployment values of cloud computing platforms appealing. Developers can go to a web page, sign up with a credit card, and instantly instantiate any number of virtual machines and applications without any IT ops involvement. Just remember, IT ops processes and procedures, and enterprise architecture rules, for that matter, exist to ensure that the overarching needs and policies of the business are followed and fulfilled. Allowing time in the deployment process to accommodate these demands may hinder time-to-market, but often there are very good reasons to do so. Later in this book, in Chapter 10 we review some of these reasons and provide our own thoughts on when it is good for business to go to the cloud and when it is bad.
WHAT ARE THE TRENDS THAT YOU SHOULD WATCH?
If you ever hear that organizations are flocking to the cloud service model and looking to leverage this offering for every part of their business, you should take that with a grain of salt. The truth of the matter is that every organization which has some established business and IT processes are taking baby steps toward cloud solutions — and rightfully so. In this section we talk about some small steps that organizations can take to begin their journey toward cloud solutions and share a few examples of organizations that have already taken those steps. This will also be covered in greater detail in Chapter 3 where we cover planning for the cloud.
Ideally, and taking the size of the organization into account, efforts to leverage cloud solutions should be done so that risk is mitigated and accounted for as much as possible. Hinging the success of an entire business unit on an offering that is still rapidly maturing and evolving in the market is probably not the best business strategy. Additionally, removing all risk from an initiative is not realistic either, as low risk often also means low returns. The trend thus far has been divided into two categories:
Identify low risk areas of your business that can potentially benefit from adopting cloud capabilities.
Find a business unit that you have a strong relationship with to pilot the new cloud service.
Of course, this decision also depends on the cloud service model that is being leveraged (IaaS, PaaS, or SaaS).
Trends towards IaaS
Organizations are applying the IaaS model to business units that require rapid provisioning of virtual machines or operating systems. This rapid provisioning however, associated with certain limitations and differences IaaS infrastructure presents, coupled with challenges related to people’s mind shift in dealing with a new paradigm, can create negative side-effects that often slow down the adoption of such a model by issues within these business units. Therefore, finding an IaaS solution that is able to tie into an existing organization’s technology, operational and culture practices, can be a bit challenging. When it comes to IaaS, there is usually one of three ways (covered throughout this chapter) in which it can be deployed: private, public, or hybrid. A private cloud IaaS solution is the most common form found in the “wild.” If you are reading this book and looking to leverage a private IaaS solution, it is most likely being provided by an internal IT Services department (common in government, financial, and retail sectors). If that is the case, the private IaaS solution will most likely already provide the capability to host virtual machines while still part of either your domain or Active Directory environment (assuming you are using Active Directory), or limit the access to your virtual machines to just your organization or business unit. If that is the case, consider yourself lucky.
For all other organizations that choose to leverage public IaaS solutions (Azure IaaS), there are a few more things to take into consideration. Although we will cover this in greater depth in Chapters 4 through 9, a few of the considerations include the following:
Connectivity and access
Disaster recovery
Data isolation and sovereignty
Identity management
After addressing some of these considerations, some business units first look to leverage IaaS solutions for their development environment, while others look to host non-mission critical application and data (freeing up their own datacenters for more critical workloads). It is not common to see organizations moving to cloud solutions in giant leaps. However taking small steps toward IaaS gives the organization an opportunity to see how this new service model will affect their organization and also to test the waters in terms of stability and flexibility as they look to increase their adoption of IaaS. Trends towards PaaS.
Although PaaS can be deployed as either public or private, most organizations look to leverage PaaS in a public cloud model. Organizations interested in PaaS in a private cloud scenario are mostly hosters and solution integrators that want to extend PaaS into a SaaS solution. We do not cover that scenario in detail in this book, but note that the capability to deploy a PaaS as an on-premises solution typically is not useful unless it will be used to provide services to other organizations (hence, the interest of hosters or at least very large organizations, which must provide IT services to other business units or IT agencies).
So, in terms of consumers looking to leverage a public PaaS solution, what are typically the trends? As far as critical applications are concerned or business units that require the rapid deployment of line of business (LOB) applications, we haven’t really seen a great deal of adoption in those key areas. Instead, PaaS solutions are used by organizations which are looking to move away from managing the infrastructure required to host LOB applications or deliver elastic workloads to external consumers (retail chain websites, government web-based portals, or externally facing LOB applications). One of the more popular public PaaS solutions is Microsoft Azure, which we of course will cover extensively later in this book.
Trends towards SaaS
Although this is the most sophisticated of the cloud service models, SaaS is probably the most common form of public cloud solution available. A common misconception about SaaS is actually derived from its name. The term software usually denotes some form of middleware, which is really closer to what PaaS offers. SaaS typically entails offering a feature or functionality within an application. An example of this would include a mailbox within Microsoft’s Office 365 suite. Whatever the middleware, SaaS assumes the management of the middleware by the service provider, and the only thing that the service consumer is aware of or concerned about is the feature that is being provided to them.
SaaS is also the most popular cloud service model because it means that service consumers can get out of the middleware and infrastructure management “game” and leave it completely to the service provider. From a cost benefits perspective this is the most appealing, as it allows service consumers to dramatically scale back the physical server footprint of hosting such middleware in their datacenters and reduces the need for expertise of that middleware application in-house, instead delegating those management responsibilities to the service provider.
You have to be very careful here, however, because moving to a SaaS solution often leads to a fairly disruptive change within an organization’s IT environments. In short, IT professionals look at SaaS as a threat to their job security. It is not uncommon to see or hear about efforts to move to a SaaS solution being sabotaged or slowed down due internal politics or fear of IT professionals losing their positions.
As organizations begin to realize the benefits of moving to a SaaS model of operations, they typically do so first by either augmenting their internal on-premises solutions or using the SaaS model as “spillover.” Meaning all new users’ mailboxes (customer accounts, SharePoint Sites, and so on) are a part of this new off-premises SaaS cloud solution. This can be challenging, however, from an architectural perspective, as the technical specifics and configuration of enabling this scenario can be fairly complex or often take more effort to set up than they provide value to the organization. For these cases, a hard cutover is often necessary. In either scenario, a fair amount of planning and preparation is required to move to an off-premises SaaS solution. As a tradeoff, your organization will lose one very large benefit that an on-premises middleware solution provides: flexibility. We will cover in more depth why this is a necessary tradeoff and whether it’s worth making some minor operational changes to help offset these limitations or re-thinking instead what capabilities are most important for your business.
WHAT ARE THE CHARACTERISTICS OF A CLOUD?
So, what are the characteristics of a cloud? The National Institute of Standards and Technology (NIST) sums it up fairly well. NIST defines all cloud solutions as having the five following essential characteristics:
Broad network access
Resource pooling
Elasticity
Chargeback (measured service)
Self-service
These characteristics are found in one of three cloud service models, which were described earlier:
Infrastructure as a Service (IaaS)
Platform as a Service (PaaS)
Software as a Service (SaaS)
And these cloud service models can be deployed in one of four ways:
Private cloud
Community cloud
Public cloud
Hybrid cloud
What we want to focus on first are the cloud attributes and the benefits they can have to your organization. Second, we want to talk through the different ways you can leverage or consume cloud solutions. Lastly we will take a look at where these cloud solutions “live” and ultimately the cost of everything in between you and your cloud solution. In the next few sections we will delve into each of the NIST defined attributes, not only in definition but also in terms of the benefits these attributes can have to your organization. In doing so, you will come to understand the textbook definition of each attribute and how it relates to the potential impact that attribute will have on your business. Ultimately, understanding the potential impact to your business is what matters most, and this is what all business decisions should be based on. Some attributes will impact organizations more than others, and the potential changes that cloud solutions will bring to your organization will be based on what benefits your business feels are most important.
Broad Network Access
NIST defines broad network access as follows:
Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, tablets, laptops, and workstations).
This is a fantastic definition, but we want to expand it in the following ways:
In order to ensure that access to a cloud solution is perceived as being stable and reliable, broad network access is required
to
the solution.
In order to ensure that the solution is capable of enabling the other cloud characteristics, broad network access must be available
within
the solution.
In order to properly maintain and administer a cloud solution, broad network access
to
the solution from a service provider’s perspective must be available.
The following subsections walk through what potential changes must be made from the perspective of the service consumer and the service provider in order to fully realize the value of broad network access.
Service Consumer
Changes:
Increase throughput or bandwidth to service provider’s cloud solution.
Benefits:
This will ensure that network access is never the bottleneck to the solution. Additionally, it enables the capability to leverage all the other cloud characteristics.
Service Provider
Changes:
Increase throughput to tenant or service consumers (may just be to the Internet).
Increase throughput within the cloud solutions (read as throughput to switches and routers).
Increase throughput for managing the solution (aside from the backbone, access to the solution from a management perspective must also be robust).
Benefits:
Eliminates network access as the bottleneck in providing the service
Enables all other cloud characteristics within the cloud solutions
Eliminates the bottleneck of ever having to manage the solution in the event of network saturation
As you can see, ensuring that broad network access is available in all aspects of a cloud solution is essential to enabling all the other cloud attributes. Without broad network access (or redundant access to cloud services, for that matter), the service consumer’s experience will be limited — and could be the sole reason why consumers may not want to leverage a service any longer.
Resource Pooling
NIST defines resource pooling as follows:
The provider’s computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand. There is a sense of location independence in that the customer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state, or datacenter). Examples of resources include storage, processing, memory, and network bandwidth.
