Autumn 2015

TIES456 Introduction to SOA and Cloud Computing, 5 ECTS

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

Course teachers

Today

• What are services and cloud computing? Why study them?
• Practicalities
• HTTP review
• Unit testing and dependency injection
• This week’s task

Services

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

A services requires three fundamental aspects : implementation; elementary access details; and a contract. (Ben Margolis with Joseph Sharpe: SOA for the Business Developer)

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 …

Wait, …

• Weren’t we talking about Service Oriented Architectures?

  • Services are the core of SOA
  • But there is a whole lot more …

• Students more interested in management and planning could consider TJTSE25 - Enterprise Architectures

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

Cloud computing (cont’d)

(source: http://www.digitalistmag.com/cloud-computing/top-9-challenges-in-cloud-computing-that-are-slowing-its-adoption-011918)

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.
  • Most in house data center usage rates are very low.
  • But it becomes cheaper again at some point (if you get the utilization rate up and management costs down)

Main course targets

• Learn generalizable techniques and skills, and not …
• Specific APIs
• Specific programming languages
• But One chart of language popularity
• Certain platforms
• …
• Basics of services
• which are just a part of SOA
• Basics of Cloud computing
• From a technical standpoint

Side targets

• Learn the Git distributed version control system
  • Split the commits over the participating students.
• 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 (last year, changes likely)

• Week 37 : A simple rest client (individual)
• 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

Goal

Why and what?

Prerequisites

Stuff to read before or during the task

Task

What you should do in more detail

Returning the task

How to return stuff

Hints

FAQ, read before asking

Returning tasks

• Everything is returned in a git repository
  • Yousource : https://yousource.it.jyu.fi/
• For the first weeks’ task : clone the teacher’s repository and add the teacher as a collaborator
  • git@yousource.it.jyu.fi:ties456-2015/week37.git
• 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

Unit testing and dependency injection

• See slides by Kamil in the repository on github https://github.com/kamiljano/teaching

This week’s task - REST client

• This week’s task … online now

This week

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