Autumn 2014

TIES456 Introduction to SOA and Cloud Computing, 5 ECTS

TIES532 - Service oriented architectures and cloud computing for developers, 5 ECTS

Course teacher

Michael (Michael Cochez)

PhD student at MIT department

Today

• What are services and cloud computing? Why study them?
• Practicalities
• HTTP review
• This weeks task

Services

A service comprises a stand-alone unit of functionality available via a formally defined interface.

Services should follow the following principles

• Abstraction
• Autonomy
• Composability
• Discoverability
• Formal contract
• Loose coupling
• Reusability
• Statelessness

Why do you want to study services?

• Services are ubiquitous and are the main building block for the Internet.
• All companies’ IT infrastructure is based on services.
• Service orientation makes adapting to change easier.
• Services uses similar concepts as modular programming and interface based design.
• Defining isolated services makes testing easier.
• See later for more …

Cloud computing

• Started as a business term
• Cloud computing is the use of computing resources (hardware and software) that are delivered as a service over a network. (Wikipedia)
  • Thus services come first
• The business aspects have difficult consequences on the implementation side
  • Security becomes a big issue when allowing multi tenancy

Why do you want to study cloud computing (1/2)?

• To make your boss happy …

Why do you want to study cloud computing (2/2)?

• More and more services are moved to the cloud
  • When developing services, you must know cloud computing
• It becomes too expensive to manage hardware yourself - especially with low load.
  • But it becomes cheaper again at some point.

Main course targets

• Learn generalizable techniques and skills, and not …
  • Specific APIs
  • Specific programming languages
  • Certain platforms
  • …
• Basics of services
  • which are just a part of SOA
• Basics of Cloud computing

Side targets

• Learn the Git distributed version control system
• Use English as a communication language
• Perform group work with new people
• Enjoy!

Practicalities

• Course mode
• Course schedule
• Tasks
• TIES532

Course mode

• No lectures
• Self oriented learning
  • Read what you need
• All content and tools are freely available
• Hands-on experience
• Individual work
• Group work (next week)

Course schedule

Only 8 weeks

5-10 credits (= 135-270 hours)

+ ————-

=Very intensive

You are expected to work outside of the lecture times!

Weekly cycle

Topics

• Week 37 : Git and Mediafire
• Week 38 : Web Service Clients
• Week 39 : Web Service Servers
• Week 40 : Authentication or virtualization?
• Week 41 : Efficiency
• Week 42 : Cloud computing basics - system administration
• Week 43 : Cloud computing - Amazon Web Services

Assignment structure

• Assignments are supposed to be a challenge
• The group should solve them as far as possible
• The goal is to learn, not only to finish the task

Returning tasks

• Everything is returned in a git repository
  • Yousource : https://yousource.it.jyu.fi/
• For the first taks : make a repository and add the teacher as a collaborator
• If unfamiliar with git
  • Read The Pro Git book on-line and instructions on yousource
  • Ask in group

TIES532

• 5 credits for assignments in TIES456 Introduction to SOA and Cloud Computing
• 5 credits for independent work on a more advanced topic in TIES532 - Service oriented architectures and cloud computing for developers
  • but only if the student finishes TIES456
  • more information later …
• No exam - TIES456 has a small test in the final lecture

HTTP (short demo)

In theory, there is no difference between theory and practice. In practice, there is.

– Attributed to Jan L. A. van de Snepscheut

Short demo of TCP and HTTP

• TCP using netcat
• HTTP server and client using netcat
• Interaction between netcat and a real HTTP server (WEBrick)
• Interaction between netcat and a real HTTP server (nginx) using the OpenWeatherMap service
  • Not all webservers are compliant (or enforce) to standards
• An example of how to write a GET request using the Go programming language

This week’s task - REST client

• This week’s task … online now

Sorting some int

• In class exercise
  • Several implementations of the same functionality were analyzed
  • It deemed impossible to find a best implementation
• A non-exhaustive list of factors which indicate ‘performance’
  • Speed
    • Processing cycles (how many steps)
    • Wall clock time (how much time when executed - in parallel )
  • Space optimization = memory consumption
  • Readability
  • Usability
    • Broadness of the domain
  • Development time
    • Familiarity with the language and tools
  • Portability
  • Maintainability

This week

• Before Thursday
  • Read prerequisite material
• On Thursday and Monday
  • Make the assignment
• Before Monday (23:59)
  • Submit assignment using git