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Cloud Computing: An Introduction


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Cloud Computing: An Introduction

  1. 1. Cloud Computing and Virtualization- Newest Trends Srinath Perera, Ph.D. Senior Software Architect, WSO2 Research Scientist, Lanka Software Foundation Member, Apache Software Foundation Visiting Faculty, University of Moratuwa
  2. 2. Next 1 hour: Goal  What is Cloud?  More on Why and When and less about How?  Take home is some idea of when to and when not to use the Cloud
  3. 3. Men, it has been well said, think in herds; it will be seen that they go mad in herds, while they only recover their senses slowly, and one by one. ~ Charles Mackay Copied from, by Rambling Traveler
  4. 4. Gold Rush  Very good example of a hype  Only few actually made money  But associated services (merchants and transportations) made lot of money
  5. 5. The Cloud Bandwagon  Is Cloud a hype? Of course it is!  Is it Just hype? may be not, thats what we will discuss. But don’t get me wrong, even if it is a hype, that doesn’t mean we should not be talking about it. Image from
  6. 6. Some Hypes Deliver: Hype Cycle  We have to understand what it is and what drives it? That would tell us how to navigate.
  7. 7. Selling Shovels In the Gold Rush Hype change the demand and supply dynamics.
  8. 8. Fire Open up the space for new Trees Hypes often change the dynamics, and give a chance for new comers to climb to the top Image from
  9. 9. So What is Cloud?  Based on the idea that computation and storage can be rented as a utility from data centers that runs somewhere (in the cloud) on demand. − Remote resources that are rented − On demand and in elastic manner − Pay as you go
  10. 10. Electricity as a Utility as an Example  Now, no one run generators themselves  Use electricity that is remotely generated  Can draw when need it  Only pay for what you use
  11. 11. Electricity as a Utility: Benefits  Small startup cost (do not have to buy a generator)  No operational cost  Do not need to do capacity planning  Overall cheaper electricity due to economics of scale  Making it parts of the everyday life, commodity (accessibility) Image from
  12. 12. Benefits of the Cloud  Avoid/reduce operational costs by outsourcing  Can scale up and down as needed  Pay as you go  Making it parts of the everyday life, commodity (accessibility)  Cheaper computing power due to economy of scale
  13. 13. Drivers of Cloud  Unused computing power at Google, Amazon  Max load >> average load  High operational cost, need for outsourcing  Availability of large scale solutions and infrastructure as side efforts of high tech company operations
  14. 14. Cloud Classification For end-users For developers, integrators, architects For infrastructure specialists
  15. 15. IaaS Example: Amazon  Two services − S3 Storage − EC2 computing cloud  Based on Virtualization, where each user is given a virtual machine and charged by the hour  Need least amount of changes to move apps to the Cloud. They in a way replace hosting services  Least amount of out of the box services (e.g. DOS attack prevention) and advanced services like scaling etc., are a responsibility of the user.  Often the best choice for ad-hoc computer users.
  16. 16. PaaS Example: Google App Engine  Support Java and Python  Support web requests and run user written web applications in an isolated environment − Java version based on servlets  Support storage based on Big table, memcache based cache, and auto scaling  Can write apps locally, test it, and then upload to the Cloud
  17. 17. SaaS Example: Salesforce  Provide support for CRM (Customer Relationship Management) software as a Service  The application available out of the box users just configure and use it.  Salesforce handles all the details, and a ideal choice for outsourcing IT functions  However, applications are very specific and customizations are limited.
  18. 18. Virtualization Mimic the hardware layer using software, and provide a “virtual” machine to the next layers − Used to mimic multiple machines within the same machine − easier manageability and migration (move machines based on load) − e.g. Vmware, Xen, KVM  IaaS uses Virtualization to provide infrastructure as a service  Virtualization can add significant overhead (each instruction become 2 instructions) − new CPUs have hardware support for virtualization, which make things better − Still I/O is a challenge
  19. 19. Cloud Platform Tradeoffs
  20. 20. Private Cloud Run a Cloud within the organization (mainly due to security concerns). e.g. Amazon Virtual Private Cloud (VPC), IBM private cloud, WSO2 Stratos private Cloud  Idea is optimizing resource sharing, utilizations, and operations − e.g. testing environments  Connection to public Cloud is possible − Amazon VPC uses VPN, WSO2 Cloud Service Gateway Image, Some rights reserved by M Glasgow
  21. 21. Potential Impact
  22. 22. More Room to Outsource Non Key Functions of a Organization  Organizations outsource their non-competitive areas to reduce costs and focus on their own expertise.  IT departments are a major cost in most organizations  Cloud enables Organizations to outsource some of the IT functions
  23. 23. Small Start Up Cost  Small start up cost − Reducing the gap between visionaries and dreamers − New organization has better chance for outsourcing operations through the Cloud − Cloud competition likely to drive down hosting prizes
  24. 24. 1 computer for 100days = 100 computers for 1 day  Great tool for occasional computations − Research labs − Reporting collecting data for a story − New york Times tiff to pdf conversion  Rise of analytics − great tool for offline analysis − Business Intelligence (BI) −
  25. 25. Large Scale Computation and Storage Resources becoming a Commodity Normal people, not just organizations can have access to computing power and storage  Computer intensive desktop apps (e.g. Excel, 3D Max)
  26. 26. Autoscaling and Cloud Bursting  Max load >> average load  Allocate based on the load  Running internal machines in an average load (because cloud is still expensive than hardware ) and scale out to cloud when there is high load − Mimic the Hybrid car
  27. 27. Dangers and Concerns
  28. 28. Privacy/ Security/ Trust  With cloud you will run your apps and put your data in an outsider's administrative domain − Can we trust the outsiders to not look at our data? Well it depends. But concern is normal for any out sourcing − Can we trust their security measures? Does the isolations are good enough? − If we are keeping data owned by others, what are the legal implications etc.
  29. 29. Latency/ Bandwidth  Why does electricity as a Utility was so successful? One key aspect was almost unlimited speed and capacity  Is that the same for Cloud? − Not really, specially for countries like Sri Lanka − Most people dismiss this, and does not even want to discuss − But for some apps (e.g. interactive apps like games) this can be a issue  Possibilities − support for offline operation − Fedex your data
  30. 30. Performance In the Cloud, your software will run on an another layer of abstractions  It will inevitably slower (3-4 times if unlucky) − Often the overhead comes from I/O − Some hit on CPU power − Expect the bottlenecks to shift  Remember performance ≠ scalability − Cloud likely to let you scale out, but performance on individual nodes likely to go down
  31. 31. Challenges  Cloud Middleware − Long running, large scale, fault Tolerant Computations − Scalable service and resource scheduling − Scalable, secure, self-managing, fault- tolerant data storage for long running processors − Multi-tenancy and Isolation − Delegation across organizations  Cloud Operations − Metering and Billing − Provisioning and Monitoring − Data Confidentiality and auditability
  32. 32. Challenges (Contd.)  Programming Model − Parallel Programming (Map Reduce) − Better App programming models – Web, Jason, APIs − Supporting Mobile devices
  33. 33. Overall Recommendations
  34. 34. Cloud Platform Tradeoffs
  35. 35. Look back: Recommendations © Copyright Kirsty Smith and licensed for reuse under this Creative Commons License  How can we benefits from the Cloud? My list of benefits were by no means exhaustive. − If you are small startup? Doing something part time (writing Apps for App Store), then cloud is for you definitely. − If you have a small data center, need to efficiently manage that and increase utilization, you should think Private Cloud
  36. 36. Look back: Recommendations (Contd.)  If your services have a Max load >> Average load, you should think about crowd bursting  If you do heavy computations once in a while (analytics, audits), then use IaaS there.  If you want to outsource some of your IT functions, think SaaS  Before leap think about 3 major concerns of Cloud? − Security/ Privacy, Latency and Performance  How much sharing and savings I need? − IaaS, PaaS, SaaS
  37. 37. Questions?