Cloud Computing Introduction PDF

Cloud Computing An Introduction M. Shukla  Lecture Outline  Definition  Essential Characteristics  Advantages  Disadvantages  Amazon Cloud Computing Platform  Google App Engine...

Cloud Computing An Introduction M. Shukla  Lecture Outline  Definition  Essential Characteristics  Advantages  Disadvantages  Amazon Cloud Computing Platform  Google App Engine  Summary M. Shukla  Definition “Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. This cloud model promotes availability and is composed of five essential characteristics, three service models, and four deployment models.” – (NIST, USA) M. Shukla   Cloud symbol - originally used as a metaphor for the Internet M. Shukla  Traditional Datacentre Issues  Design for a peak load  News related content  E-commerce sites see a major peak on certain days of year  Resources idle most of the time  Maintenance (HW/SW)  Upgrades  Rent/Electricity  … M. Shukla  Cloud computing Often compared to utility services Application Use of virtualisation Platform Infrastructure Mainframe → PC → Cloud M. Shukla Mitul Shukla  Advantages  Lower cost  hw/sw/maintenance  Applications as components  No upfront investment in software and/or hardware infrastructure  No need to build a proprietary infrastructure for a peak load  Flexible scalability  Higher utilization.  Improved reliability. M. Shukla  Essential Characteristics*  Rapid elasticity. Capabilities can be rapidly and elastically provisioned, in some cases automatically, to quickly scale out and rapidly released to quickly scale in. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be purchased in any quantity at any time.  On-demand self-service. A consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service’s provider.  Measured Service. Cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported providing transparency for both the provider and consumer of the utilized service. *NIST Definition of Cloud Computing”, Peter Mell and Tim Grance, Information Technology Laboratory, 10-7-09 M. Shukla  Essential Characteristics  Broad network access. Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs).  Resource pooling. The provider’s computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand. There is a sense of location independence in that 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 (e.g., country, state, or datacenter). Examples of resources include storage, processing, memory, network bandwidth, and virtual machines. M. Shukla  SERVICE MODELS  Software as a Service (SaaS)  Platform as a Service (PaaS)  Infrastructure as a Service (Iaas) M. Shukla  Service models analogy  Imagine a transport system People and goods Software applications Vehicles Platform Road network Infrastructure M. Shukla  SaaS  Client uses provider’s application over the network (through a browser or a client)  Client doesn’t have a control over application except some application settings  Examples  Gmail  Google Apps  SalesForce.com  (Pay-as-you-go CRM solutions)  Youtube  Facebook M. Shukla  PaaS  Delivers a platform rather than a service  API for developers  Services are limited by APIs capabilities  Examples  Google App Engine  Mosso (Rackspace)  Server platforms on demand M. Shukla  IaaS  Computer hardware (typically set up as a grid for massive horizontal scalability)  Physical footprint/hardware  Client has control over operating system, applications, firewalls)  Client has no control over underlying cloud infrastructure M. Shukla  Deployment models  Public cloud/3rd party  Run by 3rd parties  Can be much larger than company's private cloud  Portions can be reserved for a client  Private cloud/ internal cloud  Built for the exclusive use of the client  Company owns and controls the infrastructure  Hybrid cloud  Combine public and private models. Public cloud can be used to handle spikes in the load via an Orchestration layer M. Shukla  Community cloud   Deployment models M. Shukla  Foundational Elements of Cloud Computing  Virtualization  Grid technology  Service Oriented Architectures  Distributed Computing  Broadband Networks  Browser as a platform M. Shukla  Platform Virtualization  Host operating system provides an abstraction layer for running virtual guest OSs  “Hypervisor”/ “Virtual Machine Monitor”  Resides between hardware and OS  Abstraction between hardware and OSs  Enables guest OSs to run in isolation of other Oss on shared hardware  Run multiple types of OSs  Allows each Virtual Machine (VM) to reside independently and share resources simultaneously  Types: Bare metal bewteen hardware and OSs  Hosted within conventional OS as second layer, guest Oss as third layer M. Shukla  Platform Virtualization  Increases utilization of physical servers  Reduced costs  Hardware, power, cooling, administration  Reduced space  Virtual servers are hardware independent  Simplifies management, backup and recovery  Easy roll-back  Easier Disaster Recovery  Support for multiple OS  Increases security of physical host server M. Shukla  Service Oriented Architectures  Design principles for system development and integration  Model for using web services  service requestors, service registry, service providers  Use of web services to compose complex, customizable, distributed applications M. Shukla  Cloud Computing Issues  High speed internet access  Security  Privacy  Performance  Regulatory Compliance M. Shukla  Security Challenges  Attraction to hackers  Possibility for massive outages  Public cloud vs internal cloud security  Lack of public SaaS version control M. Shukla  Security Challenges  Data dispersal and international privacy laws  Exposure of data to foreign government and data subpoenas  Data retention issues  Logging challenges  Data ownership issues  Quality of service guarantees M. Shukla  Privacy  Have to trust a provider  Trusting vendor’s security model  Indirect administrator accountability  Proprietary implementations can’t be examined  Loss of physical control M. Shukla  Amazon services  Amazon EC2  Amazon S3  Amazon SimpleDB  Amazon SQS  Amazon CloudFront  Elastic IP M. Shukla  Amazon S3  Amazon S3 provides a simple web services interface that can be used to store and retrieve any amount of data, at any time, from anywhere on the web. It gives any developer access to the same highly scalable, reliable, fast, inexpensive data storage infrastructure that Amazon uses to run its own global network of web sites.  Users can specify the region  Data stored in buckets  Command line or GUI M. Shukla  Google App Engine  PaaS  Platform for developing and hosting Web applications  OS platform? HW platform?  Doesn’t matter!  Features  A fully featured local development environment that simulates Google App Engine on your computer M. Shukla  Google App Engine  Dev tools  Python  Java  Domain name limited to  “yourapp”.appspot.com M. Shukla  Administration console  Statistics  Message logs  Sign-in using a google account M. Shukla  Billable resources  CPU time, in CPU hours  Outgoing bandwidth  Incoming bandwidth  Data stored  Emails sent  A free allowance for serving 5mln requests/month M. Shukla  Summary  Essential Characteristics  Advantages  Disadvantages  Amazon Cloud Computing Platform  Google App Engine M. Shukla