The Evolution of Computing: Cloud Computing

Cloud computing has recently emerged as a new paradigm for hosting and delivering services over the Internet. Cloud computing is attractive to business owners as it eliminates the requirement for users to plan ahead for provisioning, and allows enterprises to start from the small and increase resources only when there is a rise in service demand. Cloud computing is first and foremost a concept of distributed resource management and utilization. It aims at providing convenient endpoint access system while not requiring purchase of software, platform or physical network infrastructure, instead outsourcing them from third parties.

The arrangement may beneficially influence competitive advantage and flexibility but it also brings about various challenges, namely privacy and security. In cloud computing, applications, computing and storage resources live somewhere in the network, or cloud. User’s don’t worry about the location and can rapidly access as much or as little of the computing, storage and networking capacity as they wish—paying for it by how much they use—just as they would with water or electricity services provided by utility companies. The cloud is currently based on disjointedly operating data centers but the idea of a unifying platform not unlike the Internet has already been proposed.

     

 

In a cloud computing environment, the traditional role of service provider is divided into two: the infrastructure providers who manage cloud platforms and lease resources according to a usage-based pricing model, and service providers, who rent resources from one or many infrastructure providers to serve the end users. Cloud computing providers offer their services according to several fundamental models: software as a service, infrastructure as a service, platform as a service, desktop as a service, and more recently, backend as a service.

 

The backend as a service computing model, also known as "mobile backend as a service" is a relatively recent development in cloud computing, with most commercial services dating from 2011. This is a model for providing web and mobile applications developers with a way to link their applications to backend cloud storage while also providing features such as user management, push notifications, and integration with social networking services. These services are provided via the use of custom software development kits (SDKs) and application programming interfaces (APIs). Although similar to other cloud-computing developer tools, this model is distinct from these other services in that it specifically addresses the cloud-computing needs of web and mobile applications developers by providing a unified means of connecting their apps to cloud services. The global market for this services has an estimated value of hundreds of million dollars in the next years.

 

     

 

Clearly, public cloud computing is at an early stage in its evolution. However, all of the companies offering public cloud computing services have data centers, in fact, they are building some of the largest data centers in the world. They all have network architectures that demand flexibility, scalability, low operating cost, and high availability. They are built on top of products and technologies supplied by Brocade and others network vendors. These public cloud companies are building business on data center designs that virtualize computing, storage, and network equipment—which is the foundation of their IT investment. Cloud computing over the Internet is commonly called “public cloud computing.” When used in the data center, it is commonly called “private cloud computing.” The difference lies in who maintains control and responsibility for servers, storage, and networking infrastructure and ensures that application service levels are met. In public cloud computing, some or all aspects of operations and management are handled by a third party “as a service.” Users can access an application or computing and storage using the Internet and the HTTP address of the service.

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The Evolution of Computing: Virtualization

Countless PCs in organizations effectively killed the need for virtualization as a multi-tasking enabled solution in the 1980s. At that time, virtualization was widely abandoned and not picked up until the late 1990s again, when the technology would find a new use and purpose. The opportunity of a booming PC and datacenter industry brought an unprecedented increase in the need for computer space, as well as in the cost of power to support these installations. Back in 2002, data centers already accounted for 1.5 percent of the total U.S. power consumption and was growing by an estimated 10 percent every year. More than 5 million new servers were deployed every year and added a power supply of thousands of new homes every year. As experts warned of excessive power usage, hardware makers began focusing on more power efficient components to enable growth for the future and alleviate the need for data center cooling. Data center owners began developing smart design approaches to make the cooling and airflow in data centers more efficient.

    

 

At this time, most computing was supported by the highly inefficient x86-based IT model, originally created by Intel in 1978. Cheap hardware created the habit of over-provisioning and under-utilizing. Any time a new application was needed, it often required multiple systems for development and production use. Take this concept and multiply it out by a few servers in a multi-tier application, and it wasn't uncommon to see 8-10 new servers ordered for every application that was required. Most of these servers went highly underutilized since their existence was based on a non-regular testing schedule. It also often took a relatively intensive application to even put a dent in the total utilization capacity of a production server.  

 

   

 

In 1998, VMware solves the problem of virtualizing the old x86 architecture opening a path to a solution to get control over the wasteful nature of IT data centers. This server consolidation effort is what helped establish virtualization as a go-to technology for organizations of all sizes. IT started to notice capital expenditure savings by buying fewer, but higher powered servers to handle the workloads of 15-20 physical servers. Operational expenditure savings was accomplished through reduced power consumption required for powering and cooling servers. It was the realization that virtualization provided a platform for simplified availability and recoverability. Virtualization offered a more responsive and sustainable IT infrastructure that afforded new opportunities to either keep critical workloads running, or recover them more quickly than ever in the event of a more catastrophic failure.

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The Evolution of Computing: The Internet Datacenter

The boom of datacenters and datacenter hosting came during the dot-com era. Countless businesses needed nonstop operation and fast Internet connectivity to deploy systems and establish a presence on the Web. Installing data center hosting equipment was not a viable option for smaller companies. As the dot com bubble grew, companies began to understand the importance of having an Internet presence. Establishing this presence required that companies have fast and reliable Internet connectivity. They also had to have the capability to operate 24 hours a day in order to deploy new systems.

    

Soon, these new requirements resulted in the construction of extremely large data facilities, responsible for the operation of computer systems within a company and the deployment of new systems. However, not all companies could afford to operate a huge datacenter. The physical space, equipment requirements, and highly-trained staff made these large datacenters extremely expensive and sometimes impractical. In order to respond to this demand, many companies began building large facilities, called Internet Datacenters, which provided businesses of all sizes with a wide range of solutions for operations and system deployment.

    

 

New technologies and practices were designed and implemented to handle the operation requirements and scale of such large-scale operations. These large datacenters revolutionized technologies and operating practices within the industry. Private datacenters were born out of this need for an affordable Internet datacenter solution. Today's private datacenters allow small businesses to have access to the benefits of the large Internet data centers without the expense of upkeep and the sacrifice of valuable physical space.

 

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The Evolution of Computing: Distributed Computing

After the microcomputers, came the world of distributed systems. One important characteristic of the distributed computing environment was that all of the major OSs were available on small, low-cost servers. This feature meant that it was easy for various departments or any other corporate group to purchase servers outside the control of the traditional, centralized IT environment. As a result, applications often just appeared without following any of the standard development processes. Engineers programmed applications on their desktop workstations and used them for what later proved to be mission-critical or revenue-sensitive purposes. As they shared applications with others in their departments, their workstations became servers that served many people within the organization.

  

 

In the distributed computing environment, it was common for applications to be developed following a one-application-to-one-server model. Because funding for application development comes from vertical business units, and they insist on having their applications on their own servers, each time an application is put into production, another server is added. The problem created by this approach is significant because the one-application-to-one-server model is really a misnomer. In reality, each new application generally requires the addition of at least three new servers, and often requires more as follows: development servers, test servers, training servers and cluster and disaster recovery servers.

 

  

 

Therefore, it became standard procedure in big corporations to purchase 8 or 10 servers for every new application being deployed. It was the prelude for the enormous bubble that ultimately would cause the collapse of many organization who thought cyberspace was an easy and limitless way to make money.

 

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The Evolution of Computing: Personal Computing

Initially, companies developed applications on minicomputers because it gave them more freedom than they had in the mainframe environment. The rules and processes used in this environment were typically more flexible than those in the mainframe environment, giving developers freedom to be more creative when writing applications. In many ways, minis were the first step towards freedom from mainframe computing. However, with each computer being managed the way its owner chose to manage it, a lack of accepted policies and procedures often led to a somewhat chaotic environment. Further, because each mini vendor had its own proprietary OS, programs written for one vendor's mini were difficult to port to another mini. In most cases, changing vendors meant rewriting applications for the new OS. This lack of application portability was a major factor in the demise of the mini.

During the 1980s, the computer industry experienced the boom of the microcomputer era. In the excitement accompanying this boom, computers were installed everywhere, and little thought was given to the specific environmental and operating requirements of the machines. From this point on, computing that was previously done in terminals that served only to interact with the mainframe — the so called “stupid terminals”— shall be made on personal computers, or machines that have their own resources. This new computing model was the embryo of modern cyberspace with all the services that we know today.
 

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The Evolution of Computing: The Mainframe Era

Modern datacenters have their origins in the huge computer rooms of the early computing industry.  Old computers required an enormous amount of power and had to constantly be cooled to avoid overheating. In addition, security was of great importance because computers were extremely expensive and commonly used for military purposes, so basic guidelines for controlling access to computer rooms were devised.



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The Evolution of Computing: Overview

In our time, cyberspace is an integral part of the lives of many millions of citizens around the world that dive in it for work or just for fun. Our daily life is now occupied by a plethora of user-friendly technology that allow us to have more time for other activities, increase our productivity and have a lot more access to all kinds of information. But it was not always so, and until we reach this stage we went through about 50 years of development. This series of articles will summarize the evolution of different computing models that underpin much of modern life and discuss some of the future trends that will certainly change the way we relate to information technology and interact with each other.

In recent decades, computer technology has undergone a revolution that catapulted us to a growing complexity of effects revealed in a new society and, from a certain point, we started to take for granted the use of all the technology at our disposal, without thinking about the future consequences of our actions. Therefore, amongst all that we take today for granted, cyberspace is near the top of the list. The promise of the Internet for the twenty-first century is to provide everything everywhere, anytime and anywhere. All human achievements, all culture, all the news will be within reach with just one simple mouse click. The history of computers and cyberspace is critical to understanding the contemporary communication and although they do not constitute the only element of communication in the second half of the twentieth century, they must, by virtue of its importance, come first in any credible historical analysis since they were handed a huge set of tasks that go well beyond the realm of communication.

For many internet users, the access to this virtual world is a sure thing but for many others it does not even exist. Despite its exponential growth and its geographical dispersion, the physical distribution of communications networks is still far from being uniform in all regions of the planet. Moreover, the widespread of mobile telecommunications gives cyberspace a character of uniformity which permits an almost complete abstraction of its physical support. The last few years have been a truly explosive growth phase in information technology, particularly the Internet. Following this expansion, the term cyberspace has become commonly used to describe a virtual world that Internet users inhabit when they are online, accessing the most diverse content, playing games or using widely varying interactive services that the Internet provides. But it is crucial to distinguish cyberspace from telematics networks, because there is a widespread conceptual confusion.

Telematics produces distance communication via computer and telecommunications, while cyberspace is a virtual environment that relies on these media to establish virtual relationships. Thus, I believe the Internet, while being the main global telematics network, does not represent the entire cyberspace because this is something larger that can arise from man's relationship with other technologies such as GPS, biometric sensors and surveillance cameras. In reality, cyberspace can be seen as a new dimension of society where social relationships networks are redefined through new flows of information.

We can visit a distant museum in the comfort of our home, or access any news of a newspaper published thousands of miles away, with a simple mouse click on our computer. Thus, it becomes necessary to think about a regulation of this area in the sake of the common good of the planet. The economy of cyberspace has no mechanism of self-regulation that limits its growth so the current key issues for business are getting cheap energy and keep the transmission times in milliseconds. Revenues from services like Facebook and YouTube are not derived from costs to users so, from the user's point of view, cyberspace is free and infinite. As long as people don't feel any cost in cyberspace usage, they will continue to use it without any restrictions and this is will some become unbearable.

Therefore, the purpose of these articles is to present a brief analysis of the rise and transformations through which these machines and associated technologies have undergone in recent decades, directly affecting the lives of human beings and their work and communication processes.

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How to use the Virtualization Lab (II)

Picking up from where I left, it was now time to change the setup into something very different. The first step was the creation of another VM inside Hyper-V to be used as an alternative source for iSCSI storage. I achieved this by installing the Microsoft iSCSI Target 3.3 on a new Server 2008 R2 x64 VM. I created this machine with two vhd files; one for the OS and the other one for the iSCSI storage.

I will now show you the steps taken to create three new iSCSI virtual disks:

Creation of the iSCSI target:



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How to use the Virtualization Lab (I)

I finished last post on this series with a fully working cluster installed between two Hyper-V virtual machines (VM) using a virtual iSCSI solution installed on a Virtual Box VM as depicted in the next picture:

 
Before moving on in the process of adding complexity to the lab scenario, don't forget to safeguard your work; although this just a lab, it doesn't reduce the nuisance of having to reinstall everything in the event of any failure. So, create VM snapshots:

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High Availability with Failover Clusters

Before moving on to the next chapter on my virtualization lab series, I think this might be a good opportunity to review some of the clustering options available today. I will use Windows Server Failover Clustering with Hyper-V because in today's world the trend is to combine Virtualization with High Availability (HA).

There are many ways to implement these solutions and the basic design concepts presented here can be adjusted to other virtualization platforms. Some of them will actually not guarantee a fault-tolerant solution, but most of them can be used in specific scenarios (even if only for demonstration purposes).

Two virtual machines on one physical server

In this scenario an HA cluster is built between two (or more) virtual machines on a single physical machine. Here we have a single physical server running Hyper-V and two child partitions where you run Failover Clustering. This setup does not protect against hardware failures because when the physical server fails, both (virtual) cluster nodes will fail. Therefore, the physical machine itself is a single point of failure (SPOF).

(Click to enlarge)

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How to Setup a Virtualization Lab (III)

Failover Cluster Networking

The first step in the setup of a failover cluster is the creation of an AD domain because all the cluster nodes have to belong to the same domain. But before doing so, I changed the networks settings again in order to adjust them for this purpose.

LAB-DC:IP: 192.168.1.10
Gateway: 192.168.1.1 (Physical Router)
DNS: 127.0.0.1
Alternate DNS: 192.168.1.1

LAB-NODE1:
IP: 192.168.1.11
Gateway: 192.168.1.1
DNS: 192.168.1.10 (DC)
Alternate DNS: 192.168.1.1 (Physical Router)

LAB-NODE2:IP: 192.168.1.12
Gateway: 192.168.1.1
DNS: 192.168.1.10
Alternate DNS: 192.168.1.1

LAB-NODE3:
IP: 192.168.1.13
Gateway: 192.168.1.1
DNS: 192.168.1.10
Alternate DNS: 192.168.1.1

LAB-STORAGE:IP: 192.168.1.14
Gateway: 192.168.1.1
DNS: 192.168.1.10
Alternate DNS: 192.168.1.1

Therefore, I created a domain comprised of 5 machines; a DC and two member servers as Hyper-V VMs, a member server as a VMware VM and another member server as a VirtualBox VM.

So far I have demonstrated the possibility of integrating in the same logical infrastructure virtualized servers running on different platforms using different virtualization techniques; in this case we have VMs running in a Type 1 hypervisor (Hyper-V) and in two distinct Type 2 hypervisors (VMware Workstation and VirtualBox).

The option to create a network with static IP addresses is as valid as the alternative of using DHCP. Later on I plan to explore the several options provided by the cluster networking in Windows 2008 but for the time being I kept my network in a simple and basic configuration in order to proceed with the lab installation.

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How to Setup a Virtualization Lab (II)

As mentioned at the end of my previous article, the installation of my lab continued with the creation of virtual machines on the desktop computer. But this time I used VMware and VirtualBox to explore the possibility of using a set of virtualized servers across different and competing virtualization technologies.

I insisted on the network configuration details because that is the basis of all the work ahead; a single virtual machine may be important but I want to show how they can work together and therefore the correct network configuration of paramount importance.

Import a Virtual Machine into VMware

I started by installing a VM on VMware Workstation. Better yet, I took advantage of what was previously done and used the generalized .vhd file I left behind! Since VMware does not directly support the use of .vhd files, I had to convert the file from the format used by Hyper-V (Virtual Hard Disk, i.e., .vhd) to the format used by VMware (Virtual Machine Disk, i.e., .vmdk).

The VMware vCenter Converter Standalone utility is a free application which can be obtained directly from VMware’s official site but doesn’t solve the problem as it doesn’t support this type of conversion, although it can convert from other formats and even directly from servers running Hyper-V. But what interested me was to use the work already done and so I resorted to the WinImage tool.

The process was very simple:

I selected the appropriate option from the Disk menu and select the proper source file;




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How to Setup a Virtualization Lab (I)

Now that I have concluded a general overview of most of the theory related to High Availability and Virtualization it is time to start testing some of those concepts and see them in action.

My goal for the next posts is to produce a series of tutorials showing how anyone can easily install a handful of virtual machines and be able to explore the wonderful possibilities provided by this technology. I will be using an old laptop powered by a Turion 64 X2 CPU with a 250 Gb SSD HD and 4 Gb of RAM combined with a desktop running Windows 7 Ultimate on a Athlon 64 X2 4800+ with 4 Gb of RAM and lots a free disk space scattered through 3 SATA hard drives.

Virtual Machines Creation

I will not go through the details of OS installation because I am assuming the ones reading these tutorials are way passed that.

I started by installing a fresh copy of Windows Server 2008 R2 SP1 Standard on a secondary partition in my laptop.  Once I was done with the installation of all the available updates from Windows Update and with OS activation, I was ready to add the Hyper-V role in order to be able to install the virtual machines. To do this I just went into Server Manager/Roles, started the Add Roles Wizard, selected Hyper-V and followed the procedures. Nothing special so far, right?



Note: All the pictures are clickable and will open a larger version in a separate window.

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Hardware-Assisted Virtualization Explained

Hardware-assisted virtualization was first introduced on the IBM System/370 in 1972, for use with VM/370, the first virtual machine operating system. Virtualization was forgotten in the late 1970s but the proliferation of x86 servers rekindled interest in virtualization driven for the need for server consolidation; virtualization allowed a single server to replace multiple underutilized dedicated servers.

However, the x86 architecture did not meet the Popek and Goldberg Criteria to achieve the so called “classical virtualization″. To compensate for these limitations, virtualization of the x86 architecture has been accomplished through two methods: full virtualization or paravirtualization. Both create the illusion of physical hardware to achieve the goal of operating system independence from the hardware but present some trade-offs in performance and complexity.

Thus, Intel and AMD have introduced their new virtualization technologies, a handful of new instructions and — crucially — a new privilege level. The hypervisor can now run at "Ring -1"; so the guest operating systems can run in Ring 0.

Hardware virtualization leverages virtualization features built into the latest generations of CPUs from both Intel and AMD. These technologies, known as Intel VT and AMD-V respectively, provide extensions necessary to run unmodified virtual machines without the overheads inherent in full virtualization CPU emulation. In very simplistic terms these new processors provide an additional privilege mode below ring 0 in which the hypervisor can operate essentially leaving ring 0 available for unmodified guest operating systems.

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Operating System-Level Virtualization Explained

This kind of server virtualization is a technique where the kernel of an operating system allows for multiple isolated user-space instances. These instances run on top of an existing host operating system and provide a set of libraries that applications interact with, giving them the illusion that they are running on a machine dedicated to its use. The instances are known as Containers, Virtual Private Servers or Virtual Environments.



Operating system level virtualization is achieved by the host system running a single OS kernel and through its control of guest operating system functionality. Under this shared kernel virtualization the virtual guest systems each have their own root file system but share the kernel of the host operating system.
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Paravirtualization Explained

“Para“ is an English affix of Greek origin that means "beside," "with," or "alongside.” Paravirtualization is another approach to server virtualization where, rather than emulate a complete hardware environment, paravirtualization acts as a thin layer, which ensures that all of the guest operating systems share the system resources and work well together.



Under paravirtualization, the kernel of the guest operating system is modified specifically to run on the hypervisor. This typically involves replacing any privileged operations that will only run in ring 0 of the CPU, with calls to the hypervisor (known as hypercalls). The hypervisor in turn performs the task on behalf of the guest kernel and also provides hypercall interfaces for other critical kernel operations such as memory management, interrupt handling and time keeping.

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Full Virtualization Explained

This is probably the most common and most easily explained kind of server virtualization. When IT departments were struggling to get results with machines at full capacity, it made sense to assign one physical server to every IT function taking advantage of cheap hardware A typical enterprise would have one box for SQL, one for the Apache server and another physical box for the Exchange server. Now, each of those machines could be using only 5% of its full processing potential. This is where hardware emulators come into play in an effort to consolidate those servers.

A hardware emulator presents a simulated hardware interface to guest operating systems. In hardware emulation, the virtualization software (usually referred to as a hypervisor) actually creates an artificial hardware device with everything it needs to run an operating system and presents an emulated hardware environment that guest operating systems operate upon. This emulated hardware environment is typically referred to as a Virtual Machine Monitor or VMM.

Hardware emulation supports actual guest operating systems; the applications running in each guest operating system are running in truly isolated operating environments. This way, we can have multiple servers running on a single box, each completely independent of the other. The VMM provides the guest OS with a complete emulation of the underlying hardware and for this reason, this kind of virtualization is also referred to as Full Virtualization.

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Server Virtualization Explained

You have probably heard about lots of distinct types of server virtualization; full, bare metal, para-virtualization, guest OS, OS assisted, hardware assisted, hosted, OS level, kernel level, shared kernel, hardware emulation, hardware virtualization, hypervisor based, containers or native virtualization. Confusing, right?

Fear not my faithful readers; the whole purpose of this blog is exactly to explain these things so that everyone can have a clear view over issues usually restricted to a bunch of geeks. But keep in mind that some of these terms are popularized by certain vendors and do not have a common industry-wide acceptance. Plus, many of the terms are used rather loosely and interchangeably (which is why they are so confusing).

Although others classify the current virtualization techniques in a different way, I will use the following criteria:

1. Full Virtualization;
2. Para-Virtualization;
3. Operating System-level Virtualization;
4. Hardware assisted virtualization.

On the following exciting chapters I will explain these techniques, one by one, but before that I believe it would be useful to give you a quick introduction to some underlying concepts.

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Virtualization (III)

Server Virtualization

Out of all three of the different types of virtualization discussed in this blog, I believe that server virtualization is the type of virtualization everybody is most familiar with. When people say "virtualization", they are usually referring to server virtualization because this is the main area of virtualization, whereby a number of “virtual machines” are created on one server meaning that multiple tasks can then be assigned to the one server, saving on processing power, cost and space.

Server virtualization inserts a layer of abstraction between the physical server hardware and the software that runs on the server allowing us to run multiple guest computers on a single host computer with those guest computers believing they are running on their own hardware. The physical machine is translated into one or more virtual machines (VMs). Each VM runs its own operating system and applications, and each utilizes some allocated portion of the server's processing resources such as CPU, memory, network access and storage I/O. This means that any network tasks that are happening on the server still appear to be on a separate space, so that any errors can be diagnosed and fixed quickly.



By doing this, we gain all the benefits of any type of virtualization: portability of guest virtual machines, reduced operating costs, reduced administrative overhead, server consolidation, testing & training, disaster recovery benefits, and more.

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Virtualization (II)

Network Virtualization

When we think of network virtualization, we always think of VLANs but there is much more to network virtualization than just VLANs. Network virtualization is when all of the separate resources of a network are combined, allowing the administrator to share them out amongst the users of the network. Thus, it is a method of combining the available resources in a network by splitting up the available bandwidth into channels, each of which is independent from the others, and each of which can be assigned (or reassigned) to a particular server or device in real time. This allows each user to access all of the network resources from their computer either they are files and folders on the computer, printers or hard drives etc.



The theory behind network virtualization is to take many of the traditional client/server based services and put them "on the network". Certain vendors advertise virtualization and networking as a vehicle for additional services and not just as a way to aggregate and allocate network resources. For example, it's common practice for routers and switches to support security, storage, voice over IP (VoIP), mobility and application delivery.

One network vendor actually has a working card that is inserted into a router. On that card is a fully-functioning Linux server that has a connection to the backbone of the router. On that Linux server, you can install applications like packet sniffers, VoIP, security applications, and many more.
Network virtualization provides an abstraction layer that decouples physical network devices from operating systems, applications and services delivered over the network allowing them to run on a single server or for desktops to run as virtual machines in secure data centers, creating a more agile and efficient infrastructure. This streamlined approach makes the life of the network administrator much easier, and it makes the system seem much less complicated to the human eye than it really is.

Network virtualization is a versatile technology. It allows you to combine multiple networks into a single logical network, parcel a single network into multiple logical networks and even create software-only networks between virtual machines (VMs) on a physical server. Virtual networking typically starts with virtual network software, which is placed outside a virtual server (external) or inside a virtual server, depending on the size and type of the virtualization platform.

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