Lecture 12 IaaS

Chapter 3 of the second reference book

• IaaS is the simplest cloud offerings.• It is an evolution of virtual private server

offerings• It provides a mechanism for user to use

hardware and other physical resources without capital investment and physical administrative requirements

• The advantage of IaaS : flexibility.• The challenge of IaaS: optimization.

Infrastructure Stack

Co-location

• Co-location

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• A piece of real estate - re-purposed warehouses / old factories - a barren plot of land with container based

data center modules

Images from http://www.datacenterknowledge.com

Image from http://www.datacentermap.com/

• Power and cooling are critical to the functional continuity of the data center

- redundant power supplies with backup diesel generators

- Advanced cooling technology to reduce the power costs for cooling.

-- leverage outside air during colder months -- interior design optimizes inside air flow

• Network connectivity Data centers will have links to multiple network

providers. • Environmental considerations - protection against fire, flooding, earthquakes and

other natural disarsters• Security consideration - electrical fences - surveillance systems

Hardware

• Mount hardwares (servers, storage units, and network appliances) in standard 19-inch rack cabinets.

• The challenge is to maximize the number of hardware units that can be accommodated in a standard rack cabinet.

Virtualization

• Virtualization is an enabling technology of IaaS.

- Network virtualization - Storage virtualization - Memory virtualization - Desktop virtualization - Server virtualization

• Network virtualization - virtual local area networks (VLANs): segment traffic and provide

a degree of isoloation by compartmentalizing the network

- virtual private networks (VPNs): create a secure connection between cloud entities and end users.

• Network virtualization allow applications to operate in a trusted mode whereby they can treat the cloud service an extension of the private network

• Storage virtualization: redirecting I/O requests from logical or virtual units to physical storage devices

- This abstraction of the physical infrastructure can facilitate higher utilization through pooling of units and thin provisioning

- It also makes it easy to migrate data without disrupting a service.

• Memory virtualization: abstract memory space and map it to a set of pooled memory resources

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• Desktop virtualization: can be delivered in different modes

- pre-loaded - loaded at boot time - streamed as needed - hosted remotely and simply presented on

the desktop

• The advantages of desktop virtualization inludes

- standardized environment - ease of provisioning and managing the

desktop

• Server virtualization: abstracts the underlying servers and presents them as a set of virtual machines.

• There are two kinds of software layers (hypervisors) that facilitate the abstraction.

- Type 1 hyervisor runs on the bare hardware - Type 2 hypervisor runs on an operating system

• Advantages of server virtualization - Virtual machine provides instruction set that

are independent of the physical machine, thereby enabling platforms on hardware for which they were not necessarily designed.

- It improves the level of utilization of underlying hardware.

- virtual machines can be launched from a virtual disk independent of the hardware. This encapsulation makes it easy to load-balance and to redeploy applications as usage requires

- It makes it easy to provision new instances instantly when they are needed.

Infrastructure Services

• IaaS services have three categories: - Server as a Service - Storage as a Service - Connectivity as a Service

• Server as a Service - Server as a Service can be divided into three

allocation options: Physical, Dedicated Virtual, and Shared Virtual

-- Physical allocation means specific hardwars are allocated to users

-- Dedicated virtual servers offer dedicated hardaware with hypervisor.

-- Shared virtual servers are exposed to the customers as pools of virtual machines

- Amazon, AppNexus, LayeredTech, Rackspace Cloud, Joyent, GoGrid, ElasticHosts

• Storage as a Service This service offering is characterized by a

location-agnostic, virtualized data store that promotes the illusion of infinite capacity in a resilient manner.

• Typical applications of Storage as a Service include:

- online backup - archiving - Content delivery - disaster recovery - web application development

• Amazon Simple Storage Service (S3) and Elastic Block Storage (EBS) are good examples of Storage as a Service.

• Network as a Service: provid network capabilities as services

- DHCP - Firewall - VPN - VLAN - CDN: Amazon CloudFront