The Grand Design (Part I)

I have always loved theoretical physics. I have been wanting to grab a physics book and read about any new theory or principle (chaos theory, string theory, M-theory, etc.), especially in quantum physics (the physics of small matter). New principles and theories started to accumulate and I felt like I was getting “behind” and I needed to catch up. But, a person in my position at a young startup finds it hard to allocate those precious moments of reading and researching. And coming from a computer science background, I have to do more reading and understanding than any physicist (and forget about the complexity of math that is associated with it). I came across Hawkin’s latest book “The Grand Design”, and wanted to read it. My fascination in physics was revived and I made a promise to myself that I will not just read the book, but I will also read about all the theories that it references until I have a good understanding of the whole concept proposed. Now that my laptop went crazy, I had to send it back to Dell to diagnose, and I found myself sitting here for a few days without coding. This was the perfect opportunity to finally get the book and start my quest. This post is not meant to be for scientific research. This is just my recollection of all the things that I read in the past few days from various books (I had to go back to read about Einstein’s general relativity to understand space curvature for example). I wanted to make this post as simple as possible, but sometimes it is hard to escape the “big words” that may confuse the average Joe. So, I decided to keep the post simple, but if I wanted to reference the big words, I would include a side note that starts with “Advanced”. You may skip those side notes if you are not fairly comfortable reading them and you won’t lose out.

The Grand Design is another physics book that was set out to explain the laws of the universe, to edge us closer to finding the Holy Grail of physics, the equation of everything, which is famously believed to be so simple and short that it would fit on a tshirt (and that is slowly changing to believing that maybe it is not just one equation but a few of them). Or, at least that is what physicists hope it would be. There are so many things to cover ahead of describing what this book is about, and so many things to say afterward. However, I am writing a post, not a scientific paper or a book like I said earlier. You will still have to do the further reading yourself to validate what I am saying or to learn more in detail.

In a nut shell, Hawkins (if you have never heard of him before then maybe you should stick to my other posts instead) states in his book that the universe did not need a helping hand from a divine “someone” in order to start rolling (or expanding). The biggest argument against physicists who are proponents of the new physics (string theory, general relativity, the big bang, etc.) was well if everything came from an extremely dense particle which exploded and expanded over a very short “period of time”, to form the universe, where did this particle come from? A very valid question given that physics itself firmly states that nothing comes from nothing (well until string theory came about, and I will describe it briefly in this post, where this line changed to: something can actually come from nothing provided that its total energy continues to be nothing). Then physicists replied and said: just because we don’t know the answer yet, that doesn’t mean we should give up trying and hand the credit to a divine “something”. Plus, if there was a God, who created him? And so on and so on. This debate was going on for thousands of years. With the new set of string theory variations (collectively referred to as M-theory), physicists now argue that they found the answer. Everything came from nothing and is going back to nothing! Very interesting considering this violates the first law of thermodynamics. Or, does it? How can energy come into “being” without coming from somewhere? The book took a bottom-top approach, by addressing all theories and laws that eventually contributed to the Grand statement toward the end of the book. I will do the exact opposite. I will make the statement, then dive into the corresponding explanation. If you have hung with me so far, put on your seat belt. We are going to address this right about…now.

The simplest possible term this can be put in is: “0 energy” is what this universe has in total! Even as we exist today, there is positive energy such as when work is being done on particles or objects, and there is negative energy when the particle does work and thus radiates energy away. The sum of those quantities across the universe is 0 as all positive energy cancels out the negative energy. The positive energy used to create matter as the universe started to expand was offset by the gravitational energy that wants to collapse the system back into a black hole.

Advanced: As for the matter itself (since mass and energy are interchangeable), no one knows what would cancel it out. That is where supersymmetry or super gravity theories (M-theory) came to be accepted because they state that the negative energy that is present in vacuum cancels out the positive energy of matter (although the math cannot be worked out yet with all the infinities, which is why M-theory is just a theory although with a lot of potential if proven to be finite).

Now, I am not going to dive into another big and controversial area which is “space” and “vacuum”. What is space made up of? There are many theories such as those that say space is occupied with small amounts of “virtual” particle pairs whose total sum of energy is 0 (this is what the M-theory proposes by suggesting that matter and force are two of the same, and thus there must exist something to cancel out the energy in all the matter that occupies the universe and its space). Those pairs include one particle and one antiparticle (of opposite charge) that simultaneously exist and then collide and disappear again (while radiating gamma rays). In summary, everything in the universe goes from mass to energy, back to mass, etc. And that we have equal amounts of positive energy as there is negative energy, totaling to 0.

— To be continued here —

IT Forecast: Cloudy!

Cloud computing is picking up steam (and moist). I already covered the essentials of cloud computing in two separate posts (start here). Like I did mention in my earlier posts, it is not a new technology or anything innovative. Cloud computing concepts were employed in academia and research for many years. It was used mainly to make the most out of commodity computers. The enterprise started to pay attention since the start of the post-Y2K, money-saving, lean-seeking era. I attribute the reason for that speedy adoption to three main factors:

1. Increasing cost of ever-expanding data centers, and purchasing new servers and cooling them.
2. Advancement of virtualization and associated management tools (VMware, Citrix, Microsoft, etc.)
3. Amazon’s EC2 (around 2002).

During the economic slow down this past decade, businesses looked for opportunities to reduce hardware, cooling and energy, as well as data center and their maintenance costs. Hardware manufacturers poured hundreds of millions of dollars to invest in greener and more power-efficient machines. It is evident from the newer and newer chip generations that a newer generation chip by AMD or Intel means more computing power and less power consumption. That wasn’t nearly enough in reducing costs. Companies still had to deal with ever increasing data center sizes. They moved to consolidate servers, which proved to be harder than they had anticipated as legacy applications weren’t as easy to migrate to newer servers with less available resources. Advancement in virtualization technology and its associated management tools allowed IT to consolidate servers and compact applications into smaller physical machines (still using those powerful machines, but more efficiently now) as CPU utilization increased from under 15% to much higher rates. This allowed a major reduction in size by a factor of 10 on average.

Companies jumped on the virtualization bandwagon as a way to reduce cost per physical machine, and lower power consumption by those idle servers. Virtualization also helped contain rapidly ballooning data centers. But that is not enough. Companies still have to buy expensive servers, maintain them, manage the overhead (IT staff overhead as well as physical management overhead), etc. That, along with the initial major push by Amazon that got the cloud computing engine started in the enterprise, allowed businesses to take advantage of a new face of old technology. With cloud computing, companies are able to outsource major parts of their data centers to an outside cloud service provider. They save IT overhead (cloud service providers provide their own staff), software management (security patches, upgrades, updates, etc.), hardware management (allocating physical spaces, cabling the server, rack space, etc.), and hardware cost, as companies did not need to over stack their data centers in order to manage future spikes by client requests, to only go back to a normal request cycle by their clients after those spikes.

With cloud computing, companies can concentrate on their own core business without consuming their time and effort managing this overhead that does not contribute to company’s IP or bottom line. Businesses can take advantage of a hybrid cloud to outsource their scalable-hungry applications, while keeping in-house those elephant applications (that do not change much and do not require run-time scalability). With cloud computing, companies do not need to buy powerful servers. Gone are the days when servers kept getting more and more powerful. With cloud computing, commodity computers are kings. I expect many of server manufacturers to shift their resources to building either internal (private) cloud ready servers (that replace software solutions for building and maintaining cloud-ready infrastructure) or have features and properties to allow them to plug into an existing cloud servers rack (servers with much functionality stripped out to the bare-minimum to allow lightweight-like computing machine that is green and cost-effective). The reason why cloud computing mark the beginning of the end of high-end servers is because as companies move their infrastructure to the cloud, cloud service providers will realize that to stay competitive in the per-hour resource renting space, they will need to lower their per physical server cost. To be able to do that, they will need to utilize virtualization (to maximize income per physical server), and lower physical server cost and its associated power costs. To be able to lower the cost of those servers and their power-consumption, cloud service providers will use commodity computers that are cheaper and require less energy. In the world of unlimited CPU and memory resource pools, there is no need to buy this expensive 64 GB server anymore that costs a lot more than a pool of commodity computers with the same total size of memory. Furthermore, commodity computers are stripped down to the bare-minimum features that they do not require much software management or overhead resource burning. That is why Google is building their own commodity computers instead of buying them.

Businesses will continue to outsource their infrastructure, platforms and applications to the cloud as they realize that they would become more productive if they focus on their core business functions rather than all the bells and whistles that are needed to make that happen. And as businesses outsource this overhead to a company dedicated to manage this overhead for a lot more manageable cost, IT administrators will see their jobs decaying away. IT administrators will have to find other things to do outside of their normal range of functions. They will have to acquire a new set of skills, probably in the development field as they notice the shift in IT management power from their hands to the end-user. With cloud computing, the promise of simplifying IT management is stronger than ever. An average user will be able to log on to the cloud service provider and manage their own application and infrastructure using user-friendly management pages without needing to have any prior technical background.

Cloud computing is not a revolution, but its adoption will be this coming decade. As mobile devices and notebooks market grow in size, client devices are becoming thinner and thinner, while the applications are getting richer and richer. This is only possible with hosted services that are ever-scalable, available, and fail-over ready. Those are just a few of the promises that the cloud provides. Consumers will go after smaller and cheaper devices and terminals as there would be no need for powerful laptops and desktops anymore. If I can afford to buy 5 or more dumb, thin, and very small terminals and distribute them around the house, and then buy monitors and attach them to those terminals, then I can use a VDI solution, hosted on a popular cloud service provider to load my desktop (along with my session) on any of the terminals in my house! My remotely hosted applications will be running on the supercomputer-like grid of commodity computers with all the resources they need. I can create custom-made desktop VMs for my children with high levels of control. They can destroy their VM and I can get a new one from the host service in no time! No slow computers, and no dropped and broken computers. No 10 wires per machine (just one for the terminal). This is going to be the new generation of personal computing within the next few years. I may be able to hook a 17 inch LCD to my iPhone, and be able to see my VM hosted on RackSpace.com on the LCD as if it was connected to a very powerful desktop!! How about eliminating the need for an LCD and using a projector screen? Maybe my smartphone will allow for such a project, which will allow me to take a very powerful computer wherever I go without losing speed, sacrificing battery power or even giving up screen size!

No one will benefit more from cloud computing than government, small budget businesses and non-for-profit organizations. Buying small and thin terminals (perhaps the size of one’s palm, or even a finger-size terminal) and investing much of the money on the data center (private clouds) or purchasing more and more services by the public cloud, would allow for less cost. No more worrying about back up, scalability, compliance, licensing, clustering, fail-over, high availability, bandwidth, memory, replication, disaster recovery, security, software upgrades, re-location, etc. Those are all given as promises outlined in detail in a service line agreement (SLA). Even better, those institutions and businesses will be able to deliver the same consistent service across campuses and locations.

Additionally, interoperability and integration (standards are being laid out, but will hopefully solidify and become industry-wide accepted standards within a few years) will allow companies to utilize new software and applications with a switch of a few check box selections from the cloud management page for their data center. A company can switch from using SQL Server 2008 to MySQL Enterprise with a check box selection. Users can switch their email clients from one site to another, etc. Even beyond that, a consumer can switch a whole platform from Windows 7 to Linux Ubuntu and back in a few seconds. Platforms and applications become tools and roads rather than destinations. This is only good for consumers because the ease of transitioning in and out of platforms and applications will allow for opportunity as well as caution and fear of losing customers for all businesses alike. This will result in a booming period for open source software (difficult installation and set up processes kept most open source software from the public hand), as management becomes transparent and standard.

The next decade will allow for some exciting opportunities to unfold as businesses start sprinting in a fast-pace race, after going a long decade of dieting (they became leaner) and adopting new technologies that will allow them to concentrate on their core business rather than all the extra fat (overhead).

I will write another post that will be dedicated to talk about some of the available cloud services and applications that people and small business can use immediately, in order to manage their start up or maintenance cost, without falling behind to competition that uses better software and services.

It is hard to forecast what will come next, but one thing for sure, it will definitely be cloudy!

Cloud Computing Simplified (Part II)

This is a continuation of my last post (Cloud Computing Simplified (Part I)).

I was still standing there in front of my friend. I got many questions answered and well-articulated inside my head. But, just like taking a test, thoughts are useless if the oval corresponding to the right answer on the answer sheet is not filled. Her original question was regarding her company’s website, and whether it was a SaaS or cloud. Before I enter what it appears to be a brain-trap, I need to define what a SaaS is. After all, I used to tell my students that if they could not explain any highly technical concept to their grandmas, then it is an indication that they don’t understand it themselves. I am standing here in front of a younger version of my grandma, but the statement is the same. The easy explanation of SaaS is simply “Software as a Service”. Great. Case closed. Not really. What the hell is a software? And what the hell is a service? And what does it meant to provide software as a service? We know what software is. It is any application that you use day to day. Service means that you have a black box sitting somewhere else (cloud?) that takes an input from a user and produces an answer. Think of something like a calculator. It takes numbers, and operators and produces the answer. There are a few characteristics of services. First, it has to be stateless (it does not remember you the second time you call it, and it doesn’t discriminate against who is calling it). Secondly, it has to produce one answer, which is consistent (no matter how many times and what time of the day you call the same service with the same arguments, you should always end up with the same answer – unless you are calling the getCurrentTime service :)). The last property of the service is that it is reachable via TCP/IP calls (not via mailed-letter using the post office).

So, providing the application or software as a service that is accessible from anywhere (since the web runs on a wrapper protocol (HTTP) above TCP/IP protocol), by anyone (no discrimination principle), and always consistent, is what SaaS is all about. The fact that you provide that software as a service that is callable by anyone from anywhere, then you can also create code that calls this software from another piece of software! This provides for a powerful concept on the cloud where applications are interoperable using proprietary-free calls. This allows for not only scalability across regions on the Internet but also interoperability among different cloud service providers (such as Microsoft, Amazon and RackSpace)!

The same definition of SaaS applies to all the other ?aaS resources. IaaS is nothing but offering hardware/infrastructure resources via TCP/IP API calls (S3 by Amazon is a leader in this space). PaaS is offering enabling platforms (such as Force.com and Google Apps Engine) which allow developers to create SaaS on top of those platforms on the cloud (such as SalesForce.com and Google Apps). You have other ?aaS such as DaaS (which stands for data as a service if you are talking to a data provider, or desktop as a service if you are talking to Citrix, Cisco and VMWare), etc.

The reason why ?aaS are provided via publicly-accessible API is to provide the power of management to the end user (as opposed to the IT administrator that has been hogging the power over computing resources for a long time). Those public APIs allowed many third party companies created pluggable easy-to-use management tools to manipulate those ?aaS resources on the fly. Yes, that is right, the cloud changes the concept of the Internet (or evolves it?) from a relationship where the end user is helpless recipient of what is given to him, to a more empowered user that has the ability to interact with the website and public service albeit at a minimal level (via Web 2.0 and ajax-driven applications) to being completely in control where he not only manipulates what the service has to say, but also how much resources are available to it, etc. via a user-friendly interface to the cloud service provider’s data center. Much like Turbotax, user-friendly interfaces to cloud service provider’s websites empower average cyber-joes to design their own data center and their public applications with a 16 digit magic code (a.k.a. credit card number). Although I think those “user-friendly” interfaces have a long way before they become friendly, but what we have today is a good start.

That is it, I made my friend wait too long, and if I don’t let the words out soon, I may as well switch the topic and improvise a weather joke that includes the word “cloud” in it. She did ask whether her website is a SaaS. Let’s examine this for a second. Is a website a software? That seems much harder to answer than it seems. Wikipedia defines software as “… a general term primarily used for digitally stored data such as computer programs and other kinds of information read and written by computers.” This implies that websites are considered software. This is not a typical thing from a developer’s perspective as websites seem to be just an outcome or result of a software. I actually agree with this intuition and declare that websites are results of software and not software by themselves. Just like this blog is not considered software but a few paragraphs of text. So, since a website is not software, it cannot be SaaS. However, the code that produces the website is software and is running on a server somewhere. However, although it is running on a host somewhere, it (the software itself) is not available as a service. No one interacts with this software itself. Users interact with the results of the software (i.e. website). Users cannot create code that plugs into the server side code of the web site to modify it or use it. Thus, it is not SaaS. But wait a minute, does that mean that gmail is not a SaaS? Not entirely true. It is SaaS because although it has a relatively constant interface that users cannot modify 100%, it is provided publicly as a set of APIs that can be plugged into by third party libraries to not only change the interface of gmail for particular users completely, but also extract email and most of gmail’s functionality and integrate those into a third-party application. That is something you cannot do with a third-party website.

So, finally I got to the first question and I have an answer. No, a website is not considered SaaS. Phew! That only took about two blog entries to answer! What about a website being The cloud? No, a website is not the cloud. However, it can be running on a cloud (has all the benefits of infinite scalability, FA, HA, clustering, etc.) But wait a minute. A website is not a SaaS, but it can be run on the cloud? How is that possible? Well, did you ever (as a developer) write non-OOP (object oriented program) code using an OOP language? What about forcing SOAP to manage sessions? You get the point. It is not ideal to have an application running on the cloud that is not highly service-oriented. If you end up running such a badly-designed application then you will end up not utilizing the full power of the cloud, and instead you would be using it as a simple host provider for your site. Which is what many companies do after all. The reason I say that you will not realize the full benefit of being on the cloud using a non-service oriented application (such as a website), is because if your web site has poor session management (non-distributed), then scaling it out is going to be really hard (how will you make sure when the new request goes to another instance that it will have access to the original session started on another instance? Can a user withdraw money ten times just because she hit ten different instances that are out of sync with each other?) Remember, the cloud is not something magical (outside of the context of Care Bears and their magic clouds (Care-a-Lot)). So, you must make sure that your application is SaaS ready before you can realize all the benefit of the cloud. Otherwise, you are deploying your application to one physical server on the cloud and will never realize scalability or clustering powers that are available to you for a small fee. So, a website can run on the cloud, and will utilize scalability and clustering capabilities of the cloud if and only if it is designed in such a way that makes it service-oriented. You can still have session management, but that needs to be designed to be distributed and managed outside of the services that your website server side code uses. This way, you can scale out the components that are stateless, and replicate the stateful cache.

So, in summary, the cloud continues to have the same concept it had before (as a UML-like component on a blackboard) by continuing to be the important but irrelevant part of the system. And, coming a full circle, I open my mouth, and this time I am confident that I have covered all the possible paths a curve-ball may take. I told her that her company’s website can actually be run on the cloud. In this case, it would be her company’s host provider. However, the cloud is not a one-technology thing, it is a mixture of solutions and resources. And, depending on what her company requires the web site do/offer, and the guarantees they provide to their customers about the website availability and up-time, you may have to review which cloud service provider offers the best contract (SLA – service license agreement), and she may need to check with her developers that the web site is cloud-ready and will leverage full advantage of those guarantees. She followed up with a question: “I see, so what is SaaS?” Oh man! Sometimes I wish I can copy and paste my thoughts into speech so I won’t have to repeat what I said in this blog to her again. But, it may actually be good that I will talk about it again, because this time I will have to describe what SaaS is in even simpler terms. So, I said: Well, if your web site offers a service that your customers use on the website, and would also like them to be able to use that same service on the iPhone, iPad, Droid, etc. as well as offer that exact same service to THEIR customers on their web site, then you have to provide that one service as a SaaS. Which means that your developers have to know how to design it in such a way to enable it to be detachable from your web site and available to be called and used by other third-party (your customers’) applications. Your website will use that service as well. It is good to design all those usable services as such when you go to the cloud because it will enable you to take advantage of what the cloud provides such as scalability (you can handle spikes in user requests).

She seemed to follow my statements and logic. So, maybe I did pass the “explain-it-to-your-grandma” test! Although I may have hurt my chances of having better luck having her call me back after I give her my business card so I can provide consultation on how to design such as a cloud-ready application, since my answers seemed to draw a pretty and easy picture of this whole complex cloud concept! The cloud can offer pretty much anything anybody needs on the web (because of its “potential” to be proprietary-free, interoperable, and pluggable), except the opportunity to take back what you just said to someone else 🙂

Cloud Computing Simplified (Part I)

Gartner projected that cloud computing will continue to pick up momentum next year as it cements its position as one of the top four technologies that companies would invest in. Earlier this past November, Gartner projected that cloud computing would (continue to) be a revolution much like e-business was, rather than just being a new technology added to the stack of IT arsenal.

What is cloud computing? A tech-challenged friend of mine asked one time. As I took a deep breathe before I let out the loads of knowledge that I have accumulated reading about, teaching about and working with cloud applications in its various layers, I froze for a second as I did not know how to explain it in layman’s terms. Of course if I were talking to an IT person I would get away with talking about the mouthful acronyms of ?aaS (where ? is any letter in the alphabet). However, when the person opens the discussion asking “Is my company’s website a SaaS?”, “Is my company’s website a cloud? The cloud? Running in a cloud?”, it hit me maybe there was a reason why every book I pick up or article I come across that talks about the cloud, includes a first paragraph that always provides a disclaimer that goes like this “The first thing about cloud computing is that it has many definitions, and no one can define it precisely, but we will give it a try in this book”. Maybe that is how I should start every attempt to define the cloud to someone else?

Before I answered my friend’s question, I phased out for a little bit as a big blackboard suddenly appeared in front of me with humongous set of UML diagrams (they were called UML but they included every possible shape and a verbal disclaimer for getting away from the standard diagrams by the architect drawing on the board). Those diagrams were so big and complex that people moved away from typing notes to taking pictures of the board. Including “high resolution” as an important requirement of a smart phone  before purchasing it, became an important differentiator between competitor phones (the iPhone won the war for me as it has the best resolution as of the time of this typing). High resolution was important because you see everyone in the room shouldering each other at the end of the meeting as they take a picture of the complex diagram using their phone. None of that stuck out in my mind, as I was phasing out, as much as the big cloud diagram drawn to the side of the big complex picture. That component was always known by everyone as the Cloud, and it always meant “everything else”, “something else”, “anything”, “everything”, “something”, “I have no freaking clue what there is”, etc. It was the piece that no one cared about, it was just sitting there encompassing a big piece of the entire system, yet, it was of less importance (apparently) as everything else on the board, thus earning its “cloudy” scribble to the side of the board. OK, so the Cloud is something useless that no one pays attention to? That may be a cop-out if my friend hears those words out of my mouth after a pause.

All of a sudden, something else happened. As I was dazing off, I started thinking to myself: Well, wait a minute. Did we change our definition of that little useless cloud drawn on the board? Or is it really useless? To be able to answer that question, I had to understand why the hell we resorted to drawing “everything else”, “something else”, etc. as an isolated cloud. Maybe it wasn’t useless. Maybe it was extremely important but irrelevant. Which is a big difference. Sometimes it is good to have a big chunk of your system abstracted away in its own little cloud shape being irrelevant to any other changes you make to your system. After all, if every change you make affects everything else in the system including your infrastructure, there is a big problem in your system’s design to begin with. So, maybe it was a good thing that architects had a big cloud sitting off to the side. As a matter of fact, the bigger that cloud that is not affected and does not affect your changes to the rest of the system the better! OK, so now I have solved one mystery. The cloud is the part of your system (infrastructure, platform, and software) that is abstracted from you because your system was designed correctly in such a way to have its component independent of each other. This way, you can ultimately concentrate on the business problem at hand, rather than all the overhead that is there just as an enabler rather than being fundamental to the business at its core.

But wait! If architects have been defining clouds on their boards for such a long period of time, what is so new about it? The short answer is: nothing is new about the cloud! The cloud is not something that just popped up. It has been around for a long time! From clusters of mainframes in the 60s and 70s, to GRID computing, the cloud has been there for a long time. The reason why it was picked up by the professional world just recently was due to the giant improvements in virtualization management tools that allowed the customer to easily manage the complexity of clouds. OK, I am getting somewhere, but I still haven’t gotten to my friend’s questions. Maybe I should continue to go deeper to find more answers first before I unload my knowledge, or lack-thereof! Going back to the board. Was every cloud really a cloud? After all, sometimes an architect draws a cloud around a piece or a component that she doesn’t understand. So, there has to be a difference between the cloud that a knowledgeable architect draws versus someone else that had it mistaken for another UML diagram component.  So, what defines a cloud? Well, it is an abstracted part of the system. It may encompass infrastructure, platform and/or software pieces.

That is the easy part. Here comes the more technical part. The cloud provides infrastructure, platform and software on an as-needed basis (service). It gives you more resources when you need them, AND it takes away extra resources you are not using (yes, the cloud is not for the selfish of us). To be able to call it a form of Utility Computing (where you pay only for the resources you use), an additional cost factor is associated with the resources you use on an hourly basis (or resource basis). Yes, if it is free, then it is not the cloud. No place for socialists on the cloud. We will skip this argument of paid versus free because you will tell me that many cloud-based applications are available for free, and I will tell you that nothing is free because those same applications provide a free version (which is just a honeypot for businesses) and the paid version (which is where businesses need to end up just to match the capabilities of their in-house software). The cloud may be free for individuals like me and you who don’t care about up-time and reliability, but I am focusing my discussion here on businesses (after all, an individual will not have their own data center, or require scalability, etc.)  So, I win the argument, and we move on!

Another condition is for all those resources to be available via TCP/IP based requests (iSCSI or iFC for hardware, web-services API calls for platform and software resources). It is important that requests and responses to cloud’s resources go on the web, otherwise you cannot scale up to other data centers sitting somewhere else. The cloud is scalable (“infinite” resources), DR (disaster recovery) ready, FA (fail-over) ready, and has a very HA (high availability). The last three characteristics are made possible by a few technology solutions that sit on top of the cloud such as virtualization, although virtualization is not a necessary component in a cloud due to the use of commodity computers factor which is to be discussed below. With virtualization management tools, DR – for applications only, FA and HA are provided out of the box,  DR for databases is made possible by replication (and acceleration and de-duplication techniques sped up the process across physical LANs) tools. Scalability is provided by the SOA (service oriented architecture) characteristics of the cloud of its independent and stateless services. Another component that is essential to defining what a cloud is, is the use of commodity computers. It is essential because single CPU power is not relevant anymore as long as  you have an infinite pool of your average joe-CPU. Google builds its own commodity computers in-house (although no one knows the configurations of such computers), and it is believed that Google has up to 1,000,000 commodity computers powering its giant cloud. If the cloud service provider is using powerful servers instead of commodity computers, that is an indication that they don’t have enough computers to keep their promise of scaling up for you. The reason why both properties cannot co-exist is because if the provider can have “unlimited” powerful servers, that implies that to offset their cost (especially cooling) they would have to provide the service to you for extremely high prices, offsetting the benefit of moving to the cloud versus having your own data center. Many people also believe the cloud to be public (meaning that your application will be running as a virtual machine right next to your competitor’s on the same physical machine with a low probability – albeit bigger than 0%).

Many companies choose to run their own “cloud” data center (private), which theoretically violates a few of the concepts we defined above (cost per usage, unlimited scalability). That is why some don’t consider private clouds to be clouds at all. However, to their dislikes, private clouds have dominated the early market as companies have bought into the cloud concept but they still fear that it uses too many new technologies, which makes it susceptible to early security breaches and problems. Amazon had a major outage in the East region in Virginia toward the end of 2009 (which violates the guarantee that your services are always available as they are replicated across separate availability regions). So, we know what private clouds (internal data centers designed with all the properties of a cloud minus the cost per usage and unlimited resources), and what public clouds are (gmail anyone?). What if you want a combination of both? Sure, no problem, says the cloud. You have the hybrid cloud (using a combination of private clouds for your internal, business critical applications that do not require real time scalability to public services on public clouds where you push your applications that require the highest availability and scalability (Take Walmart’s web site around the holidays for example). This is going to be the future of the cloud as there are always going to be applications that do not need the power of the cloud such as email (does not need to scale infinitely in real time), HR, financial applications, etc. There is a fourth kind which is a virtual cloud. This is having the advantage of both worlds (public resources but private physical data centers). You have access to a public cloud, but your own secure isolated vLAN that you can access via VPN over HTTP (IPSec). The virtual cloud will guarantee that no other company’s applications will be run on the same physical hardware as your company’s. Your internal applications will connect to your other services sitting on a public cloud via secure channels and dedicated infrastructure (on the public cloud).

If you are confused about how applications (for various companies) can be running on the same physical machine and why in hell you would want to do that, check out my two series articles about virtualization.

— To be continued here —

Virtualization – Under the Hood (Part II)

This is a continuation of my last post (Virtualization – Under the Hood (Part I)).

Q: Can you actually have more memory allocated than available physical memory? And how?

Short Answer: Yes. Through  many techniques including: Transparent page sharing, page reclamation, balloon driver, etc.

Long Answer: You can actually start many VMs with total allocated memory that is more than the physical memory available on the server because not all applications will utilize 100% of their requested memory at all times. Page reclamation allows the hypervisor to reclaim unused (previously committed) pages from one VM and give it to another. Another technique a hypervisor may use is to allow VMs to share memory without them knowing it! Sounds scary, but nonetheless manageable by the hypervisor. This allows more VMs to start with their full requirements of allocated memory met, although they may be sharing memory pages with other VMs. Lastly, there is the approach of ballooning memory out of a VM. This is more of a respect driven approach by the hypervisor where it requests memory from all executing VMs, and they would voluntarily balloon out all the memory pages they are not using. Once they need the memory back, the hypervisor will send it back after obtaining it from other VMs using any of the methods above. Swapping pages with the hypervisor is an expensive operation. That is why you should always start your VM with a pre-set Reservation amount (minimum amount of memory guaranteed to the VM by the hypervisor). However, the more you reserve upon start up of your VM, the less VMs can be fired up on that same physical host.

Q: How do you make sure your application is highly available?

Short Answer: It depends on the approach, and the virtualization suite you are using. You either take things into your own hand and cluster your application over 2+ VMs, and make sure you replicate necessary data over to the redundant VM(s), or use the tools provided by virtualization suite to move the VM to a less utilized or crowded host.

Long Answer: High availability of VMs can be jeopordized in one of two ways:

1. Either your VM is running on a highly utilized host, making your applications less responsive. In this approach you can utilize the virtualization suite to transfer or migrate your running VM to another host that is less crowded. vSphere provides vMotion, which is used by their HA appliance to migrate your VM to another host without taking the VM down! They actually start copying your VM byte by byte starting with the section of your memory that is not or under utilized at the moment, while keeping track of all “dirtied” pages since the last transfer to re-transfer again to keep it consistent on the new host. At some point the hypervisor of the first machine will turn off the VM, while the other hypervisor on the target machine turns it on simultaneously. Microsoft added Live Migration to their R2 release of HyperV to do just that. There are many metrics and thresholds that can be configured to trigger such an action. Dynamic Resource Scheduling (DRS) in vSphere allows you to set those parameters and move away from the cluster, DRS will manage to move your VM from one host to another to ensure highest availability and accessibility.

2. When a host goes down, another VM needs to fire to start taking requests. This can be done using virtualization suite tools (only when data replication is not required). However, when you need to cluster your data as well then you will need to introduce data replication yourself such as Microsoft SQL Server clustering. This will allow the new VM to immediately serve requests as soon as the first VM goes down. Of course there will need to be some sort of switch control at the virtualization suite management level or using an external context switch appliance such as NetScaler.

Q: Is virtualization the equivalent of parallel processing on multiple processors?

Short Answer: Yes and no.

Long Answer: Virtualization introduces the capability of borrowing CPU cycles from all CPUs physically available on the host. The side-effect of this is introducing the effect of parallel processing. However, the only reason a hypervisor would want to borrow cycles from another CPU is because the first CPU it had access to is fully utilized. So, technically, you are not really parallelizing to run things in parallel, but rather to use as much of the CPU cycles as your application needs to run its single- or multi-threaded code.

Q: Since we are running multiple VMs on the same host, doesn’t that mean we share the same LAN?? Wouldn’t that be a security threat if one application on one VM was missconfigured to access an IP of a service on another VM?

Short Answer: Yes. But we don’t have to share the same network even among VMs on the same host.

Long Answer: You can create virtual LANs even between VMs running on the same physical host. You can even use firewalls between VMs running on the same host. This way you can create DMZs that keep your applications (within your VM) safe no matter which VMs are running on the same host.

Q: Since a hypervisor emulates hardware, does that mean that my guest operating systems are portable, EVEN among different hardware architectures?

Short Answer: Yes.

Long Answer: Most virtualization suites support x86 architectures because they are “better” designed to take advantage of virtualization. It also depends on the virtualization suite you are using, and what guest OS it supports (for example vSphere does not support AIX). Additionally, although in theory those guest OS and their hosted applications are portable, it also depends on the hypervisor’s own implementation of drivers on the system. The hypervisor code does not use the drivers installed inside the guest OS, but its own set of drivers. The implementation could vary from one system to another, one device to another. So, you definitely may end up with different behaviors or performance on different hardware even using the same VM.

Note: The Open Virtualization Format (OVF) is a standard format to save VM in so you can migrate them to another virtualization suite (not just hardware!) However, not many virtualization tools support this format yet.

Q: What about security? Who controls access to VMs?

Short Answer: Virtualization suites provide user management. This list is separate from application users.

Long Answer: There are many layers of user roles and permission management in a virtualization suite, depending on the suite itself. Typically, you can create users, define their role, their access to VM, and what type of permission they get. You can even create pools of VMs and apply the same set of user role/permission combination. This eliminates having to manage security and authentication on each individual hypervisor, and instead, do the management across a host of them.

Q: Ok, ok, ok. How about the dark side of virtualization?

Short Answer: There are many problems or potential problems with virtualization. It is not all roses.

Long Answer: There could be many reasons why not to use virtualization including:

1. With virtualization, now you are collapsing the system administration and networking team (and possibly security as well) into one team. Most (if not all) virtualization suites do not provide various roles of managing the virtualized datacenter based on those divisions. Once you have an administrator access to managing the virtualized datacenter, all divisions are off at that point. This can be seen as a good thing. However, it is mostly a bad thing because a system administrator is not necessarily a person that is highly specialized in dissecting the network among all the various applications based on the requirements and capabilities of the enterprise.

2. Upgrading or updating one application or VM requires a lot more knowledge in its requirements and potential effects on other VMs on the same host. For example, if an application doubles its memory requirements, the IT administrator managing the virtual environment must know even if the increase in requirement comes on a host that has that enough physical memory. In a traditional environment, as long as the physical memory is available, the IT administrator deploying the updates or upgrades does not necessarily need to know of the new memory requirements of the application as long as no additional physical memory needs to be attached to the server. This change forces administrators of the virtual environment to be more aware and knowledgeable of the applications and VMs running in their system, which is not a hard-line requirement in traditional systems.

3. If the number of VMs fall under 10 or so per host, then you maybe adding more overhead than realizing the benefits of virtualizing your machines.

4. Testing and debugging system events are a lot more involved now as an administrator has to chase the VM wherever it goes in order to check the trail of events across those machines, plus look at the guest OS even logs to complete the picture before understanding the problem.

5. Created VMs will require physical space as well (for the VM files themselves). This is an overhead, and if not managed correctly you may end up bursting your storage capacity bubble with over-creating VMs.

6. Miscellaneous: expensive management tools, new IT skills to be learned, single point of failure (if one host goes down, it will take down many VMs with it), more bandwidth headache if one physical host starts up (making many VMs initialize while starting up at the same time), etc.