1. Introduction to Cloud Computing
and the Amazon Cloud
1st CloudCamp Athens
Colab Athens Oct 1, 2011
Fotis Stamatelopoulos
@fstama
http://linkedin.com/in/fstamatelopoulos

2. About the Presentation
20' presentation
○ What is Cloud Computing
○ The Amazon Cloud
○ Case study

3. What is Cloud
Computing ?

4. "The Cloud"
Different meaning: (a) user perspective, (b) software engineer /
systems perspective
source: wikipedia.org
source: shanghaiwebhosting.com

5. Cloud Computing
● The natural evolution of widely used technologies and
computing paradigms, like:
○ the client-server model
○ virtualization (dynamic multiple "virtual" machines
contained into a physical one)
○ the service oriented architecture
○ utility computing
● The "Cloud Computing" buzzword focuses more on the
business model than on the technologies involved
○ computing/network resources consumed on demand
○ elasticity - scalability
○ service, resources managed by the provider

7. Type of Cloud Computing Services
● Based on the service offered:
○ Infrastructure-as-a-Service (IaaS) - Amazon AWS
○ Platform-as-a-Service (PaaS) - Google Appengine
○ may also include Software-as-a-Service (SaaS) -
SalesForce.com
● Based on ownership:
○ Public clouds - offer services to everyone
○ Private clouds - in-house solutions
○ Hybrid clouds - little bit of both

8. the goal of cloud computing is to provide
on demand, scalable access
to computing resources
& IT services

9. How ?
IaaS: you built your software and rent
○ Virtual machines (time based)
○ Storage (e.g. bytes per month)
○ Traffic in/out (per month)
○ Additional services (via API calls)
○ Deploy your software components and
you manage elasticity & scalability
PaaS:
○ Deploy your specially designed application and the
service handles elastic usage of resources / scaling
SaaS: you rent the usage of a software product
○ on a subscription basis (per user cost)
○ or on demand (time & per user cost)
○ some application customization is offered

11. What, how, why in 3 bullets...
● What's Amazon Web Services: pay-as-you-go access to
cloud infrastructure and elastic services via REST/SOAP
and/or a Web-based console.
● How (simplified):
○ create machine images (AMIs)
○ launch VMs (boot from AMIs)
○ attach persistent volumes (EBS vols)
○ login and install software & applications
○ (optional) use other AWS services via REST/SOAP
● Why:
○ dynamic, elastic usage of resources
○ cost-effective high availability (e.g. S3)
○ pay on usage (hourly-rate)

12. ... in a picture

13. Snapshot of the management console

14. AWS products & services
● EC2: your virtual machines in predefined HW configurations
● EBS: persistent block storage (faster than S3, slower than
volatile EC2 instance disks)
● S3: object (file) storage via REST/SOAP, high availability
and geographical replication, also used for your AMIs
● CloudFront: Amazon's CDN
● Cloudwatch / Autoscaling: monitoring and scaling of EC2
● Elastic Cache: distributed in-memory cache

15. AWS products & services (cont'd)
● SQS: distributed queue
● SNS: notification service(messaging / topics & events)
● SES: scalable, bulk e-mail service
● SimpleDB / RDS: Amazon's NoSQL / RDBMS services
● Elastic MapReduce: Hadoop on EC2/S3
● and more on deployment and management, payments/e-
commerce, networking... etc

16. Costs
● There is a free usage tier: new user sign-up, one year for a
Linux micro instance
● Pay as you go for what you use
○ pay usage per hour
○ pay for traffic (volume)
○ pay for storage (volume)
○ pay for I/O operations / transactions
● Much more expensive than the typical rented physical
machines / VMs

17. Expensive? Why should I use it?
● Cost effective high availability
● Elasticity, easy to scale up/down dynamically
● REST-based infrastructure management & monitoring
● Massive processing power for short periods
○ e.g. launch 10.000 VMs for a week
○ MapReduce big data projects
● It's not cost-effective to use EC2 instances for your low-
traffic web site (maybe on the free-tier)

18. Real world case study
MyNeworkFolders.com

19. ● SaaS offering implemented by EBS.gr
● A distributed, scalable and elastic file storage platform that:
○ supports access via multiple user interfaces (web
browser, mobile devices, desktop, WebDAV)
○ provides an API for building custom client applications
○ it is based on EBS's open source project gss-project.org
● It is designed for operating in the cloud, currently deployed
at the Amazon cloud.

21. High level architecture requirements
● MyNetworkFolders requires multiple servers for hosting its
software components:
○ duplicated (for fault tolerance) front-end web server
○ cluster of (at least two) application servers
implementing the core business logic
○ database cluster for storing meta-data and other info
○ search / indexing server cluster for full text search
○ a secure, efficient and scalable file storage system
● All these add up to at least three virtual servers and can
easily grow to clusters of tens of servers.

22. Hosted vs the Cloud
● Old school hosting solution: private or rented physical
servers in a data center:
○ always maintain and support a minimum number of
servers even when the load is low
○ energy & cost efficient adaptation to fluctuating load is
almost impossible to achieve
○ scaling up requires buying/renting and setting up new
physical servers (and supporting equipment)
■ for the application
■ for the storage subsystem
○ high operating costs for a small company, especially for
achieving a high level of fault tolerance / availability

23. Hosted vs the Cloud
● Having mynetworkfolders.com hosted in the cloud:
○ use and pay only what we need
○ easily and dynamically grow or shrink resource usage
(and energy consumption) to meet fluctuating user
demand during the day
○ easily scale up (more virtual servers) when the user
base increases, or when new functionality is added
○ economy of scale offers high availability and fault
tolerance in an affordable cost
○ minimize operational costs

24. AWS Technologies & Products Used
● Currently using in production:
○ EC2 for server instances (app, db, search,admin)
○ S3 - reliable, replicated file storage
■ the main reason we used AWS
○ CloudWatch (monitoring)
● Plan to use:
○ Elastic Load Balancing
○ CloudFront

25. Thank you! Questions?
@fstama
http://linkedin.com/in/fstamatelopoulos