CLOUD 101

Cloud is one of the 4 technologies (Mobile, Cloud, Social and Big Data) that make up 3rd Platform.

Cloud is... a self-service, automated, virtual data center environment. While I'm sure there are exceptions to that rule, when things are not well defined you pick a simple definition and go with it.

A Data Center is made of up of:

• Physical Servers - 1U or 2U rack servers or blade style servers are common.
• Physical Networking - wires, switches and routers to direct packets of data over wires
• Physical Storage - Block and File storage arrays as well as local disk storage in servers
• Security both physical (building, cameras) and digital (firewalls, intrusion detection systems, etc)
• Power & Cooling + backup generators for emergency

Server virtualization is often the first step in trying to gain control over costs and complexity while adding much needed agility.  Step 1. choose your hypervisor platform.

Hypervisor Installed on top of Physical System

A hypervisor is a sort of tiny operating system that gets installed on the bare physical server and allows the administrator to logically segment the physical server into many virtual servers running on the same physical server. Each logical virtual server will have it's own operating system such as Windows or Linux. Each of the virtual servers running on the physical server will not be aware that it has been virtualized. Popular companies and their hypervisor platforms are:

Vmware's vSphere         Citrix's XenServer       Redhat's KVM       Microsoft's Hyper-V

 Virtual servers allow you to pool the physical server's resources such as CPU, Memory and NICs (Network Interface Card). Most applications only require about 10% of the resources of a single physical server. By installing a hypervisor on a physical server you can run on average eight virtual servers that will consume 80% of the available resources. This is where you get the majority of your capital expenditure savings. CAPEX savings is often given as a reason for virtualizing.

After virtualizing your server environment you quickly realize that operationally everything is still a manual process. When a business unit requests an application be deployed, IT still must go through the manual steps to deploy that application all while the business is waiting.

1. Select a physical server running a hypervisor that has enough unused resources to support the creation of a VM (Virtual Machine) on it.
2. Configure the VM container resource amounts (CPU, RAM, Storage, Networking) 
3. Load an OS (Operating System) on the Virtual machine.
4. Configure the Networking for the VM. 
5. Provision the Storage for the VM.
6. Add the VM to the list of IT monitored VMs
7. Delete or archive VM when no longer needed by business

Cloud technology is the automation of the steps above and allows IT to deliver applications to the business faster.  

Cloud Deployment Models:

1. Private Clouds - automation is done by IT in their own private DC (Data Center). 
2. Public Clouds - automation is done by a CSP (Cloud Service Provider) in the CSP's own data center not the private customer's location
3. Hosted Private Clouds - a CSP dedicates a portioned off set of servers, networking and storage for exclusive use and administration by private IT company.
4. Hybrid Clouds - Moving of VMs between a compatible private and public clouds.

Hybrid Clouds

While Private cloud allows the business to keep 100% control and security of their applications and data, it requires them to build & operate the private cloud CAPEX & OPEX. Public clouds allow the company to only pay for use but with the downside of loosing control over the operation and security of their data. Hosted private clouds allows the CSP to purchase, configure and be the "hands and eyes" on the servers, networking  and storage while the business knows the hardware is for exclusive use by them. The exclusive use part is important because it improves security and allows the CSP to allow IT some level of administrative access into the configuration and operation of the hosted private cloud. 

The last deployment model called Hybrid cloud is the best of both worlds. Some workloads (applications) may run on the private cloud because of security or controllability. Often the most critical applications to the business require high uptime and rapid response time when anything does impact the applications availability. Less critical workloads may benefit from being deployed on a public cloud. Hybrid cloud computing gives the ability to move workloads sometimes even non-disruptively (to the users of the application) back and forth between private and public clouds. 

Service Models - 'X - aaS'

Cloud Service Models

1. IaaS - Infrastructure as a Service - upload or select & configure your VM on the IaaS cloud. Examples: Vmware's vCloud Air, AWS EC2, Microsoft's Azure 
2. PaaS - Platform as a Service - write your custom application on and/or upload it to a private or public PaaS cloud. Examples: Cloud Foundry, Heroku, AWS Elastic Beanstalk, AppFog, etc
3. SaaS - Software as a Service - pay a fee and get a username/login to use a CSP provided application. Examples: Salesforce.com, Cisco WebEx, ADP, etc.

Consumption / Pricing Models:

• Pay as you go - order a VM on IaaS, deploy an app on PaaS or a login on SaaS and pay for only what you use and discontinue the service at any time without penalty. While this pricing model is the most flexible it can come at the cost of unpredictable service levels. 
• Contract basis - Sign a short term 30 day contract or a longer multi-year contract. CSPs can and will often guarantee some level of service in exchange for the longer contract. 

Service Level Agreement:

     CSPs as part of the cloud service will offer what is called a SLA (Service Level Agreement) which is a contract stating what the users of the cloud service can expect for Bandwidth, compute resources, service uptime, problem resolution times, etc.

Self-Service

Self Service:
        Cloud technology automation makes it possible to have a Service Catalog ( a webpage listing all the services offered for rent/lease). Users of the cloud can simply select a service from a menu of choices and have that service provisioned automatically in the CSP's  datacenter or locally on IT's own private cloud datacenter.

Business Value of Cloud:

      Competition is everywhere these days. Business must innovate and bring there ideas to market faster that everyone to gain market share and profits while keeping costs at a minimum. Business needs technology and IT to deploy it for them. IT is in the critical path of nearly everything a business needs these days. Cloud technology is allowing IT to move at the speed of
business.