Agenda:
To understand basics of Cloud Computing and it
flavors
Walkthrough IaaS a type of Cloud computing
Walk through layers of IaaS
Introduction VMware vSphere / Microsoft Hyper V
Pros/Cons
References/further studies
Basics of Cloud Computing and
it flavors
Cloud computing is a system
for enabling convenient, on-demand network access to a shared pool of
configurable computing resources e.g., servers, storage, applications/softwares,
and services that can be quickly provisioned(is term used
in IT to setup and ready to use) and released with minimal user effort or service
provider interaction.
If you google about cloud computing you see
similar description all over the internet. Let’s break it down. In earlier days, network designers while
modeling network plan they used to mention cloud diagram for unknown/somebody
else problem/work. When you/company/govt. anybody needs a pool of
computing resources like a computers, software, storage (photos, videos
remember iCloud or google drive), you can approach cloud service providers like
amazon, Microsoft and many others. Once you approach them and using their
applications/websites within few minutes you can set up your computing
resources.
So when you don’t want rent office space, hire network engineers, buy
computers upfront, less capital … solution is cloud computing.
I know still many grey areas about cloud
computing, let’s get into detail of it. Here is the trick/how cloud service
providers do the magic of providing cloud computing services on demand (means
when you need it start using it and when you don’t stop/cancel the service). Data Centers: is huge building, inside you see hundreds of
blade servers, storage racks, virtual servers, network setups … usually data
centers will be setup strategically(geographically, environmentally). Typically
with one data center cloud provider can provide service to hundreds of
customers.
In brief, log in to cloud provider website,
register and with few button clicks from your office/home couch you can setup a
computing resources. Isn’t ridiculously simple?
Flavors of Cloud: There are many jargons used inside cloud
computing like SaaS, PaaS,
IaaS,… these are all slightly different services provided over network
to end customers. Let’s look into them briefly
SaaS (Software as a Service): You got married,
photographer took excellent photos but you still you feel to do little touch up
to your photos. So will you buy photo editing software paying upfront $$$ just
to edit pics, after that you won’t use it or just rent it for a day get done
your work and just pay fraction of $? Obviously later, that’s it that is the
Software as a Service, pay per use. All you have do is login to SaaS provider
website pay per use and exit. Isn’t it cool?
PaaS (platform as a Service): It’s a computing
resource with windows, linux or mac platform. Within few clicks of button on
service provider website, a virtual machine will be ready for you, all you need
is internet and you can login to that vm from your laptop or desktop.
IaaS (Infrastructure as a Service): a pool of
virtual/physical machines, storage, networks. This flavor we shall discuss in brief
later sections.
You got a wonderful startup idea, but you don’t have
computers, required software’s and also lot of money. With little money and
help of cloud service providers you can set up 10 to 20 computers, software’s
with less time and start implementing your ideas. If successful continue the
service, worst case you can turn of cloud services.
Ex: Amazon EC2, Microsoft Azure, Office 365,
Outlook365, Gmail for organization, Salesforce...
Walkthrough IaaS
IaaS or Computing as a Service is basic Cloud
computing service. It is the first thing we can think of when somebody talks
about cloud computing. In fact researcher at Cambridge first developed virtual
machine software called Xen.
Basically idea of virtual machine is simple, On top of hardware/OS, a
hypervisor layer sits which helps to create virtual machines in which we can
install different OS and run parallel in a box. Hypervisor software takes
advantage of modern powerful hardware which at any point of time won’t be
consumed by user, so creates an abstract layer and distributes/shares computing
resources across multiple virtual machines.
IaaS: can be pool of virtual machines/physical
machines, storage, servers, network… IaaS provider will take care of
security/patch updates to the virtual/physical machines, on demand computing
power increase/decrease (RAM, Processors)
Walk through layers/internals
of IaaS
Here is what typical work flow looks like inside a cloud
company/datacenter, when you or an organization requests for computing
resources from cloud service provider. Its number sequential work flows as
follows.
UI Layer: First
you will land in cloud provider website. User interface/web site where
customers login from their location, and create/update cloud service request.
For ex: you are starting up a new business and you need 5 computers(virtual
machines). Just login like www.cloudprovider.com.
Business
Logic Layer: Once user submits his/her request like how many
virtual machines, software’s, operating system(platforms) they need. Business
layer where they have hardware, software stock details in DB. Number of
business logics will trigger and instantly give feedback to customer that how
much time/minutes will take to complete their request via UI. Business layer
does many checks like enough blade server available or not, storage and many
other tasks before invoking workflow engine.
Orchestration/Work
Flow Engine: After updating the user about request status,
business layer passes client request to work flow engine. Which will have
algorithms to execute clients request sequentially, ex: first create virtual
machine, install OS, applications like ms office… if any step fails it will
update system/db and exits. Some major cloud vendors provide work flow engine
live status so that they can what’s going on.
Virtual
Machine Management Center: Hypervisor(like VMware, MS Azure..) creates
virtual machines. Usually scripts will exists, workflow engine just invokes it
and script will does all the activities like, create, update VMs, installing a
server automation client inside VM…
Hypervisor is one of the key component of cloud
computing, because most of the cloud request is for virtual machines. Hypervisor provides excellent client\UI to
monitor and control the virtual machines, through which we can know whether a
partical VM is up or down, status of it. Using client you can increase ram,
processor, … I am just mentioned few feature of hypervisor but it does lot of
other complex tasks like clustering,
if a VM goes down, automatically another VM boots up its called high availability …
Server
Automation: as name says it does many server related
activities like installing OS in VM, patch’s/security updates.
Network
Management: set up network/vLan, IP management and other
network related activities.
Above mentioned points/steps involves complex tasks, I am just trying
to simply and give an idea what goes on inside a Datacenter. Each steps have
separate dedicated team, hundreds of scripts to execute automatically in
synchronized way and its team work, together they make cloud work.
Introduction VMware vSphere /
Microsoft Hyper V
Pros:
·
No upfront investment for infrastructure like servers,
software’s, storage, network. Pay per use.
·
No worries about security/patch updates. Cloud
service provider will take care of it.
·
On demand computing resource increase or decrease,
for ex: increase RAM, Processor when required and later turn it off
Cons:
·
You will be locked with one service provider, it’s
very hard to migrate to different provider in current cloud architecture
·
Availability. Even cloud giants experience
network/service outages.
·
Internet connectivity. No internet no cloud
·
Long term cloud seems more expensive than in house
server setup.
References
I recommend you to go through above links, they
have very good tutorials and documentation. If you like to become AWS / Azure
developer it takes some time to get your feet wet, but you can learn and start
developing programs with in short span of time. Writing small or simple
programs is key to understand a new concept
