Your SlideShare is downloading. ×

Cloud Computing: An Introduction


Published on

Published in: Technology

  • Be the first to comment

  • Be the first to like this

No Downloads
Total Views
On Slideshare
From Embeds
Number of Embeds
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

No notes for slide


  • 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. 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. 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. Gold Rush  Very good example of a hype  Only few actually made money  But associated services (merchants and transportations) made lot of money
  • 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. Some Hypes Deliver: Hype Cycle  We have to understand what it is and what drives it? That would tell us how to navigate.
  • 7. Selling Shovels In the Gold Rush Hype change the demand and supply dynamics.
  • 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. 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. 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. 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. 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. 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. Cloud Classification For end-users For developers, integrators, architects For infrastructure specialists
  • 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. 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. 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. 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. Cloud Platform Tradeoffs
  • 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. Potential Impact
  • 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. 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. 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. 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. 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. Dangers and Concerns
  • 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. 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. 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. 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. Challenges (Contd.)  Programming Model − Parallel Programming (Map Reduce) − Better App programming models – Web, Jason, APIs − Supporting Mobile devices
  • 33. Overall Recommendations
  • 34. Cloud Platform Tradeoffs
  • 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. 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. Questions?