1 / 25

Lecture 2: Introduction to Cloud Computing

Lecture 2: Introduction to Cloud Computing. Xiaowei Yang (Duke University). Roadmap. What is Cloud Computing? Why now, not then? Classes of Cloud Computing Cloud Computing Economics: why does it make sense? Obstacles and (research) opportunities. What is cloud computing.

elani
Download Presentation

Lecture 2: Introduction to Cloud Computing

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Lecture 2: Introduction to Cloud Computing Xiaowei Yang (Duke University)

  2. Roadmap • What is Cloud Computing? • Why now, not then? • Classes of Cloud Computing • Cloud Computing Economics: why does it make sense? • Obstacles and (research) opportunities

  3. What is cloud computing • Applications run on clouds (Software as a Service) • Hardware and system software in the datacenters that provide the services • An old concept: computing as a utility • No need to purchase your hardware • Pay-as-you-go

  4. Cloud Computing = SaaS + UtilityComputing – PrivateClouds • Private • A business’s internal datacenters • No public access • Name a few companies that own private clouds • Public • Pay-as-you-go public services • Name a few public cloud providers

  5. Who’s whom

  6. Is Cloud Computing Win-Win? • SaaS advantages to providers • Simple management and maintanence • Centralized control over versioning • SaaS Advantages to users • Always on service • Easy data sharing and collaboration • Robust data storage • Simple management • …

  7. Advantages of utility computing to users • On demand scaling (elasticity) • No up-front commitment • Pay-as-you-go reduces provisioning risk

  8. Examples • When Animotomade its service available via Facebook, it experienced a demand surge that resulted in growing from 50 servers to 3500 servers in three days. … After the peak subsided, traffic fell to a level that was well below the peak. • With traditional computing  buy servers  idle servers • With cloud computing  pay during peaks  release afterwards

  9. Incentives for cloud providers • Making money • Wholesale (10,000s) at a larger scale is 5-7 times cheaper than retail at a medium size (100s - 1000s) • Resource multiplexing • Leveraging existing investment • Companies may already build private clouds for other businesses • Defend a franchise • Migrating existing customers to a cloud

  10. Attacking an incumbent • Google vs MS • Leveraging customer relationships • E.g. IBM • Preserving relationships by offering a branded cloud computing service • Becoming a platform • More customers  more $$

  11. Why now? • Two enablers: • New business model: pay-as-you-go with no contract • Intel Computing Service in 2000-2001 required a contract and longer-term use and failed • Customers do not like commitment • New applications • Mobile + cloud • Parallel batch processing: tons of data today • Analytics • Compute-intensive desktop applications

  12. Classes of Utility Computing • Infrastructure as a service (IaaS) • Thin API, close to bare metal • Virtual machines with customized guest OSes • Applications run on virtual machines using OS APIs • E.g. Amazon EC2 • Platform as a service (PaaS) • Sandbox environment with specific platform APIs • E.g. Google AppEngine • A mixture of both • Microsoft Azure

  13. Economic benefits • Elasticity • Peak demand: 500 servers • Average demand: 300 servers • Q: when does it make sense to use a cloud?

  14. Reducing underprovisioning risk • Poor performance turns customers away

  15. Real world examples • Target uses AWS • Other retailers use it during holiday seasons

  16. Rule of Thumb • UserHourscloud x (revenue – Costcloud) >= UserHoursdatacenter * (revenue – Costdatacenter/Utilization) • Why Costdatacenter/Utilization? • Do UserHourscloud == UserHoursdatacenter

  17. Comparing costs

  18. When not to use a cloud? • Utilization = 100% • Shipping large amount of data

  19. Obstacles and Opportunities • Availability • Single point of failure • Mega-Cloud to improve reliability • Elasticity to defend against DoS attacks • Ex. 500,000 bots at $0.03 per bot, 1GB/s attack traffic • Victim: $360 per hour in bandwidth and $100 of computation, (500 bots per instance) • Attack must last long (>32 hours) • Make bots detectable

  20. Obstacles and Opportunities • Data Lock-in • Not a pure technical problem • Marketing strategy •  Standardarization • Data confidentiality and auditability • Technical challenge • Encryption would help

  21. Obstacles and Opportunities • Data transfer bottlenecks • Need creative solutions • FedEx • Keep data local to a cloud • Cheap long haul bandwidth by reducing high-end router cost • 2/3 of bandwidth cost is from routers

  22. Obstacles and Opportunities • Performance variation caused by I/O sharing • More research

  23. Obstacles and opportunities • Scalable storage • Research to build scalable storage systems • Bugs • Debuggers, tracers • Scaling quickly • Research • Reputation fate sharing • Spammers used EC2 • All services sharing their IP addresses got blacklisted • Research

  24. Obstacles and opportunities • Software licensing • Not pure technical challenges • Commercial software’s licensing model not good for utility computing • One time purchase vs pay-as-you-go • Opportunities • New licensing models • New sales models • Open source software!

  25. Summary • What is cloud computing • SaaS + Utility Computing – Private Cloud • Enablers • Business models • New applications • Advantages • Economic benefits • Challenges and opportunities • Technical • Non-technical

More Related