Lecture 9: cloud computing I

the cloud computing Phenomenon

• cloud computing is seen as a leading disruptive technology in the coming decade
• cloud is driving optimization and innovation of business models in organization
• trends like mobility , Big Data , and social media are also influencing cloud adoption

What is Cloud computing

• A model for enabling ubiquitous , convenient , on demand network access to shared pool of configurable computing resources (server, storage , networks , applications , and services 0 that can be rapidly provisioned and releaed and minimal management effort or service provider interaction
• A cloud is a collection of network accessible IT resources
• consists of shared pools of hardware and software resources deployed in data centers
• Cloud model enables consumers to hire a provider's IT resources as a service

Essential cloud Characteristics

• on-demand selof service
• Broad network access
• resource pooling
• Rapid elasticity
• Measured service

On-demand self service

• A consumer can provision computing capabilities , such as server time and network storage , as needed automatically without requiring human interaction with each service provider
• Consumers use a web-based self-service portal to view a service catalog and request cloud services
• enables consumers to provision cloud services in a simple and flexible manner ( reduces the time needed to provision new or additional IT resources

Broad network access

• capabilities are available over the network and accessed through standard mechanisms that promote use by heterogenous thin or thick client platforms (smartphone , mobile ,tablets , laptop)
• consumers access cloud services on any client / end-point device from anywhere over a network
• standard mechanisms support the use of heterogenous client platforms :
• TCP/IP PRotocol
• Soap and Rest web services

Resource pooling

• The providers' computing resources are pooled to serve multiple consumers using a multi-tenant model , with different physical and vitual resources dynamically assigned and reassigned according to consumer demand . there is a sense of location independence in the customer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (ex; country, state ) ex of resources include storgae , processing ,memory and network bandwidth
• enables providers to improve resources utilization and to flexibly provision and reclaim resources

Rapid elasticity

• Capabilities can be elastically provisioned and released in some cases automatically to scale rapidly outward and inward commensuarate eith demand demand . to the consumer , the capabilities available for provisioning often appear to be unlimited and can be appropriated in any quantity at any time
• consumers can adapt to variations in workloads and maintain required performance levels
• consumers may be able to avoid excessive costs from over-provisioning resources
• scalling can be done in 2 ways : vertical scaling = scalling up involves adding more resources to IT Infrastructire . horizontal scaling (scaling out ) involves adding more cpmponents to an IT Infrastructure

Measured Service

• cloud systems automatically controll and optimize resources use by levarging a m( storage metering capability at some level of abstraction appropriate to the type of service st some level of abstraction appropraiate to the type service ( storage , processing , bandwidth ,a nd active user accounts) Resource usage can be monitored , controlled , and reported ,l providing transparency for both the provider and the consumer or the utilized service
• enables billing of cloud services
• resources monitoring helps providers with capacity and servivce planning

cloud computing Benefits

• Business agility : enables quick resource provisioing
• facilitates innovation
• reduces time-to-market
• Reduces IT costs; reduces up-front CAPEX
• REDUCES ENERGY AND SPACE CONSUMPTION
• IMPROVES resource utilization
• HIgh availabilty
• ensures resource availability based on consumer/s requirements
• enables fault tolerance
• Business continuity
• reduces impact of downtime
• ex: cloud based backup
• flevible scaling : enables scaling of resources to meeet demand
• automatic resource scaling

cloud computing benefits

• flexibility of access :
• enables access to services from anywhere
• eliminates dependency on a specific end-point device
• Application development and testing : enables application development and testing at a greater scale
• enables testing on multiple platforms
• simplified infrastructre management : consumers manage only those resources that are required to access cloud services
• increased collaboration : enables sharing and simultaneous access of resources and information
• masked complexity : Intracacies of IT operations are hidden from the end users

Cloud service models

• A cloud service model speco=ifies the services and the capabiliteies provided to the consumer
• NIST specifies three primary cloud service models;.
• IIaaas : THE CAPABILITY PROVIDED TO THE CONSUMER IS TO PROVISION THE PROCESSING, STORAGE , networks ,a nd other fundamental computing resouces where the consumer is a ble to deploy and arbitary software , which can include operating system and applications
• the consumer does not manage or control the underlying cloud infrastructure but has control over the operating system ,storage ,a nd deployed applications ; and possibly limited control of select networking components (host firewalls)
• Paas
• Saas