1. Cloud Computing
CLOUD COMPUTING
ARCHITECTURE
At the base of the above graphic is the
WHAT YOU WILL LEARN WHAT YOU SHOULD KOW world of physical infrastructure. Above that
is the enterprise IT or collocation providers
• Ephemeral & persistent clouds • Application architecture (ISP’s, ASP’s, MSP’s, etc.) These are the peo-
• State migration • Server hardware ple that have all the server rack and stack ex-
• High frequency low latency • Basic cloud perience. Above that we have Citrix on the
• Server motion • Basic enterprise architecture desktop, VMware on the server side, and now
• Hypervisor vs. operating system • Basic internetworking increasingly Amazon. These are the organi-
zations that have made all the money (in the
middle layer) «marking the physical virtual» so
INTRODUCTION SOLUTION LOCK IN far. Now the battle is making it easier to own
Clouds are very popular these days. It seems This is a difficult problem to solve and it exists and operate.
like everyone has a cloud. A world full of because enterprises are far too willing to lock Above them we have users trying to use
clouds and we’re not just talking about the themselves into a solution or a given course of these things and get things done. In front of
ones for sale from the vendors (Amazon, action. We keep seeing this over and over again. them we have a whole host of company’s trying
Microsoft, Google, Salesforce, etc.). Everyo- In my view, this increases overall risk even thou- to help them do that. These company’s howev-
ne has their own cloud. The constant that gh in the grand scheme of things it makes no er have a defined set of viewpoints and biases
I’m seeing in the industry is that private en- difference because what most businesses want that you need to be very aware of.
terprises and governments have their own to do is solve a problem and they will use the On the ground working each and every day
clouds and all of these clouds are not inte- simplest and easiest tool to solve that problem. are these company’s with there internal beliefs
roperable. and biases.
FACT Customers (you) end up being assaulted by
INTEROPERABILITY No one has portability and as things exist to- these service providers and there automation
One cloud will not work with another cloud. day, expect to be locked into a given solution. provider rhetoric. The service providers see
In addition to a cloud, everyone has an API. everything from down below and everything
So go talk to any vendor you choose and the CLOUD & CLOUD RISKS they see is about making the physical virtual
conversation will quickly turn to that ven- How the enterprise is thinking about using and that’s the world they live in.
dor’s API and its “openness.”. This works the cloud? Today it exists as a simple three Automation providers see things from
well if you only need to deal with one ven- part model. above. They sit above multiple clouds and
dor and that vendors API is open and well
documented but as we all know that’s not
always the case.
QUESTIONS
TO THINK ABOUT
• What happens if I need to consume mul-
tiple clouds?
• Do I need to track the evolution?
• Do I need to track the way that these
API’s evolve over time?
Most organizations will find that this is a non
starter. However the industry is working on
the creation of cloud standards.
TIP
The Delta Cloud Project is an abstraction
layer that exists above API’s and since everyo-
ne has an angle and an API, the Delta Cloud
project is gaining momentum.
1 Data Center 1/2011

2. CLOUD COMPUTING ARCHITECTURE
they see a «smooth landscape of innovation» ficult to get it out and they blame the cloud FACT
and sometimes they don’t take into account all architecture. All the big vendors have some form of mo-
the dirty mess that it takes to get to get to that tion.
level of abstraction. DATABASE & STATE MIGRATION: The principle behind server motion tech-
A common complaint from people using BLAME THE CLOUD nology is that If my physical server is about to
the Amazon cloud service goes something This is one of those unique things about the fail, I now have the ability to move the serv-
like this «We had an EC2 instance that we’ve cloud. The cloud gets blamed for things we’ve er’s load somewhere else. This sounds simple
been using for a few months to do some de- been dealing with forever and sometimes peo- and very interesting however when you talk
velopment, and for some reason the instance ple think that operations folks come with the to the people that use it every day, you see
is no lover available on AWS. We had to shut cloud to handle all the system administration a set of interesting use cases and these use cases
it down yesterday because we were no longer work and they don’t. are pretty reduced compared to what you will
able to access it, and we were planning to fol- Let’s think about the following real world find from the vendors.
low up on this today, but we logged in an hour statements:
ago, and the instance was no longer there. How CLOUD ARCHITECTURE:
can we recover from this?» Well, it’s an instant • «Did you know, if you have 1TB of data in KEY MOTION DESIGN
store cloud that’s part and parcel of this kind EC2, you can’t get it out in 30 seconds?»-- CONSIDERATIONS
of approach. Of course not! If I have 1TB of data in my
Another common complaint is «we had a Downtown, NY (proprietary/private/ • Network distances need to be very small
spot instance for the last couple of months blade datacenter) I can’t get that out in 30 • Links should be at least 10GB per second
setup for testing and we’re in the middle of seconds either. • Create a specialized network just for the
moving data off the server and late today it • «You should make something that moves act of moving the server
disappeared.» Well, here we see that the spot that data really fast somewhere else» and • Shared SAN between the devices
price got hit. After all you’re using a pricing «The problem with the cloud is you have • Moves must occur from exactly the same
mechanism in the Amazon system that says to manage where your data is.»-- Nothing type of cpu and sub cpu to exactly the
they can shut your instance down if your price new here. We have been dealing with all same type somewhere else
gets hit. these issues for a very long time. The most
common request I get is for me (or a ven- You’re going to need to know everything about
TIP dor) to «make something» that can move the physical infrastructure. A complete un-
Understanding your cloud pricing mechanism the data out of the cloud really fast, like derstanding of the physical infrastructure will
because it has a very real impact on your data. 100x faster, and this is where you get in- need a key virtualization strategy. In the wild, I
These are just some of the hidden issues in to the realm of Physics.-- You just have to see that this initiative is frequently overlooked,
the cloud that are causing a lot of confusion manage where your data is. and like «state», it’s ignored.
for cloud users.
TIP CLOUD ARCHITECTURE:
EPHEMERAL CLOUDS & PERSISTENT Manage where your data resides in the cloud. SERVER MOTION = COPYING
CLOUDS This is a critical cloud architectural concept.
Then there are «persistent clouds» where you CLOUD ARCHITECTURE: STATE All server motion is the process of copying
bring up an image, save it, and it’s always there When it comes to cloud architecture, «state» is something somewhere. The metaphor of
(in the cloud) effectively on the cloud hard the big problem; however this is not unique to «moving» is what gets people confused because
drive until you delete it. cloud computing so if you embark on a cloud they say «oh, they moved it» and you point to
There are also «ephemeral clouds» and Ama- strategy, and you expect the cloud to magi- other strategies, wait, that’s not really fair, you
zon behaves as both. This is causing problems cally solve your state problem, then you’re kind of copied it.
on both ends of the spectrum. Ephemeral im- putting the emphasis in the wrong place. With the types of stateless architectures we
ages disappear (leading to confusion) and the There are thousands of vendors who get up have today (remember the state of those state-
persistent ones are being treated as low cost every day and work to solve specific state prob- less Apache web servers? A few weeks ago
blade servers. lems, for specific architectures, for specific those could have been copied to another cloud.
Customers will have Apache Server 1, verticals. The state of those stateless JBoss servers? Well
Apache Server 2, Apache Server 3-- all saved State is the problem and it’s not unique to those could have been to another cloud two
on the virtual cloud hard drives at a hosting cloud computing. So for someone that worries weeks earlier as well.) You can look at other
provider and now a few months later, Apache about milliseconds of latency like a high fre- techniques that look more like a stateless serv-
server 2 is not the same as apache server 1. This quency, low latency, trading network capabil- er motion. These techniques won’t require
occurs because they have moved a server blade ity for trading center- thinking about millisec- short network distances, can be cross cloud,
procurement/operational model to the cloud onds of state motion between two locations and you still get the same capability.
and *not* a development/operational model is something they have been thinking about Look beyond the simple capabilities. Re-
to the cloud. it forever and they will continue to do so. It’s member your point of view: cloud users point
something you’ve been managing forever and of view vs. service provider’s point of view.
TIP it’s something you are going to need to con- How are you doing to do mobility vs. how they
Move development/operations based models tinue to manage. are going to do mobility?
to the cloud and not blade based models.
CLOUD ARCHITECTRE: CLOUD ARCHITECTURE: HYPERVISOR
DATABASE & STATE MIGRATION SERVER MOTION TECHNOLOGY vs. THE OPERATING SYSTEM
Large enterprises are quickly discovering that Welcome to vMotion, XenMotion and the When it comes to marketing hype, the people
if you put a lot in, it’s increasingly more dif- world of server motion technology. behind the «you don’t need a server operating
Data Center 1/2011 2

3. Cloud Computing
system anymore» win the prize for creative SAMPLE APPLICATION You need to build your plan around the
writing. If you do infrastructure or you’ve set ARCHITECTURE & REDUNDANCY: reuse of people and their skills. Again, in the
up private cloud before then you’ve heard all And to the degree that you need to redo every- world of system administration and operations
this before-- «You only need a ‘thin layer of soft- thing, you already did (over the last 10 years) (2+ million people) do you think they like the
ware’ we call a ‘hypervisor’ [sometimes called the evolution of the enterprise cloud ready ar- sense of infinite risk, change, and pain? -- No.
a VMM virtual machine monitor]»-- This is chitecture has already arrived. Let’s take a look However that’s how it’s going to be perceived
effectively something like a Linux Kernel or at a plain old application that consists of: when you say you have to redo everything. Do
a Linux Distro or something very close to it those people know how to do Bash scripts?
except your just buying it from your virtuali- • APACHE (5 servers) Can they learn a new scripting language? Sure.
zation vendor. • WEBLOGIC (6 servers) <-LINK TO-> Do they know config files, do they know client
ABC CORP. EMS (6 servers) VPN’s, Lan-To-Lan VPN’s? Yes. The monitor-
FACT • ORACLE DB (4 servers) ing tools that you use? Your network security?
A hypervisor is effectively a Linux kernel. Yes. All of that should be brought to bear end
You could blow away 3 of the apache servers, 3 reused where possible.
TRIVIA of the web logic servers, and part of the oracle In general, renovation is the watchword
The term «hypervisor» is not new. It was first cluster and this thing still runs. instead of revolution, unless you’re one of
used in 1965 to refer to software that shipped That means that in terms of operational these new businesses that’s «antiprise» (an-
with an IBM RPQ for the IBM 360/65. windows, you can bring down any of these ti-enterprise). A company who’s born in the
Well at this point, Mr. Hypervisor custom- servers and your load balancers and proxy serv- cloud, your entire staff is in the cloud, you
er is on the phone and he would like to have ers will deal with it. You only have to worry effectively have no infrastructure in place,
a word with Mr. Operating system and he’s a about state. At the end of the day, this type of then for you this is an opportunity for com-
little upset. The reason he’s upset is that all loosely coupled architecture works really well pany’s of that elk to take the lead and take the
current Linux operating systems can run vir- in the cloud if you don’t have to drag your en- floor- I wouldn’t recommend it for the aver-
tual machines (complements of KVM and of tire datacenter with it. So if you can move this age enterprise.
course Windows Server can run virtual ma- type of infrastructure to the cloud and treat What’s generally happening around us
chines as well) so from a marketplace point that could deployment as a subnet of your now, again, from an enterprise specific point
of view, the two dominant marketplace oper- datacenter network you will be successful be- of view is just the beginning of the long slow
ating system families can all run virtual ma- cause now you don’t have to move: migration of the traditional enterprise to ag-
chines and we have a lot of system adminis- ile infrastructure; whether public, private or
trators who know how to handle operating • DAP hybrid cloud. The industry is on board with
systems. • Single sign-on large amounts of capital and some very smart
We have a lot of well established infra- • License manager people are working on this endeavor—you can
structure in development infrastructure/op- • Media repository benefit from this momentum.
erational infrastructure for installing operat- • Installer, etc.
ing systems so the question of how much do
you need a “specialized mechanism” is going Now all of a sudden the cost of renovation, of RESOURCES
to be an interesting part of the battle mov- using a cloud deployment for this type of ar-
ing forward. chitecture, is very low. You have already done a • The Delta Cloud Project http://www.del-
lot of the re-architecting over the last 10 years. tacloud.org.
CLUD ARCHITECTURE: Keep that in mind as you move to this type of • GoGrid http://www.gogrid.com.
DOING NOTHING architecture. • Amazon Elastic Compute Cloud
Please don’t underestimate the power of do- (Amazon EC2) http://aws.amazon.com/ec2.
ing nothing. Just going along and listening to CLOUD ARCHITECTURE: TOOLS • Microsoft Cloud Services http://www.Micro-
all the things from the various providers and Myth- “You absolutely need new monitoring soft.com/Cloud.
not committing. Re-architect everything for tools.” Not always the case. If you have net- • NIST - National Institute of Standards and
the clouds? We’re not in that place yet- and work extent to your cloud servers, then why Technology http://www.nist.gov/index.html.
here is why. So the myth is «of course as you can’t you continue to monitor them with the • Book - The Challenge of the computer utili-
look at it from above, wouldn’t it be grand if existing mechanisms? You can. We can go into ty by Douglas Parkhill.
you could redo everything.» but how many more detail in subsequent articles but in es- • Book - The Mythical Man-Month: Essays
enterprises «redo everything»? Not many. sence you’re dealing with the same amount of on Software Engineering by Fred Brooks.
latency. So if you currently use Tivoli for that • InterviewTomorrow. Net - Helping Amer-
CLOUD ARCHITECTURE: application I would say that you’re doing some- ica get to work. Free access to the 2011
RE-ARCHITECTING thing wrong if you don’t continue to use Tivo- executive recruiter database.
Re-Architecting for the clouds? When you li for that application (or Nagios or Microsoft
talk about risk of failure x the outcome x the Operations center, etc.) ABOUT THE AUTHOR
threat, etc. how often do you want to launch Richard C. Batka is a business & technology ex-
projects where you redo everything? It’s just SUMMARY ecutive who is based in New York. Mr. Batka has
not a fun thing to do and to the degree that Your enterprise internal view is really driv- worked for global leaders such as Microsoft, Price-
you need to redo everything, you’ve already en by your idiosyncratic history. That being waterhouseCoopers, Symantec, Thomson Reuters,
been doing it over the last 10 years. Enterprise said— please don’t feel like you shouldn’t re- and JPMorgan Chase. A graduate of New York
architecture has slowly evolved to cloud ready think a few things because you should and University he can be reached at rbusa1@gmail.
application architecture. there will be some opportunity for redo just com of followed on Twitter at http://twitter.com/
not massive redo. RichardBatka.
3 Data Center 1/2011