‘Cloud Ready’ Design through

Application Software Infrastructure

Florin Coros

About me

Co-Founder@florincoros

Partner & Co-Founder

blog.iquarc.com/florin

Outdated Enterprise Software

3

Enterprise Software

Old Technologies

Costly to maintain

and update

Re-Implement on a Modern Architecture

Legacy System

• High costs to update

• Shetty UX

• Outdated functionalities

• Not scalable, not reliable

Modern System

• Accessible everywhere

• Actual technologies

• Good maintainability

4

On-Premise or Cloud or Both?

5

Build and Operate for On-Premises

Deployable in Azure

Enable a gradual migration into the Cloud

Cloud migration does not require a

rewrite or reengineering

First phase use IaaS

Second phase use PaaS

Quality

Isolation

Separation

Build, Test and

Deploy for

On-Premises

only

Large and

Complex

System

Deployable on

Azure

Use PaaS

6

Source code dependencies can only

point inwards

• Nothing in an inner circle can know anything

at all about something in an outer circle

• Abstractions and application concepts are

independent of frameworks

• frameworks are used as tools, not to cram the

system into their limiting constraints

7

http://blog.8thlight.com/uncle-bob/2012/08/13/the-clean-architecture.html

Separate the core of the app from

the frameworks and the mechanisms

What did we already do?

8

DesignEnvision

solutions

Setup rules

and practices

Managing

Complexity

Quality

Change

Separations

Abstraction &

Encapsulation

Explain &

ValidateDiagrams Prototypes

Importance of Managing Complexity

when projects do fail for reasons that are primarily

technical, the reason is often

uncontrolled complexity

9

Importance of Managing Complexity

Scalability

Availability

Multitenancy

Security

Authorization

App Infrastructure Enforces the Architecture

Application Infrastructure

The Application Foundation

Wrongly Built House

Different Solutions to the Same Problem

Which one is the ONE?

App Infrastructure – Primary TOOL to

Control Complexity and Size

How to do it?

Invest in Design and App. Infrastructure

Enforce consistency

Enforce structure

Focus on Modularity, Abstraction, Encapsulation

Independent

Modules

Hide the

frameworks

Manage Dependencies

Dependency

Injection

Discoverability

18

Good Design vs Bad Design

http://martinfowler.com/bliki/DesignStaminaHypothesis.html

iQuarc AppBoot Library

Lightweight library that handles the startup of an application

Implements

Separation of Construction

and Configuration from Use

Modularity

Defines and abstracts a

modular application

Makes the application

independent of the host

process

Dependencies Management

Dependency Injection

Enforces consistency in

declaring dependencies

Encourages good practices

Encourages separation

between data and behavior

20

iQuarc AppBoot: Modularity

<<Interface>>

IModule

+ Initialize()

Application

+ Initialize()*

+ Modules[]

AppModule1

+ Initialize()

AppModule2

+ Initialize()

• Modular Application Support

• Application modules do not depend on

Frameworks

• Application can be hosted in any .NET process

\iQuarc\AppBoot

Application Hosted in Any .NET Process

• The application is not aware of the process it is

hosted in

• The application is isolated from framework specifics

• The host process is not aware of what modules it

hosts

• The host process is isolated from application logic

• Benefits:

• Flexible deployments

o same host can load different modules depending on

configuration

o Flexibility in development and testing

• Framework setup is separated from application setup

22

<<Attribute>>

ServiceAttribute

+ ServiceAttribute()+ServiceAttribute(Type contract)+ ServiceAttribute(Type t, Lifetime lifetime)

Bootstrapper

+Bootstrapper(Assembly[] assemblies)+Run()

Application

+ Initialize()

\iQuarc\AppBoot

App Boot: Dependency Injection

<<Attribute>>

ServiceAttribute

+ ServiceAttribute()+ServiceAttribute(Type contract)+ ServiceAttribute(Type t, Lifetime lifetime)

Bootstrapper

+Bootstrapper(Assembly[] assemblies)+Run()

• Makes Programming Against Interfaces the de

facto programming model

• Abstracts and hides the Dependency

Container

• Provides a maintainable mechanism for

declaring services implementation

• Dictates how Dependency Injection is used\iQuarc\AppBoot

public IEnumerable<Policy> GetPolicyFromMutation(Mutation mut)

{

var policies = repository.GetEntities<PolicyImage>()

.Where(image => image.MutationId==mut.Id)

.Select(image => new Policy

{

Id = image.PolicyId,

ValidAt = image.Mutation.Date

//..

}).ToList();

// do other calculations / grouping on data

return policies;

}

public void CalculateChanges(ChangeEvent change)

{

using (var uof = repository.CreateUnitOfWork())

{

var policies = uof.GetEntities<PolicyImage>()

.Where(i => i.Status == ImageStatus.Calculating &&

. i.EvendId == change.Id);

foreach (PolicyImage image in policies)

{

image.Ammunt = GetAmmountFor(image, change);

}

uof.SaveChanges();

}

}

Encapsulate Data Access Concerns

<<Interface>>

IRepository

+GetEntities<T>() : IQueriable<T>

<<Interface>>

IUnitOfWork

+SaveChanges()

Database

Repository UnitOfWork

<<Stereotype>><<DTO>>

Plan<<DTO>>

Contract

+CreateUnitOfWork() +GetEntities<T>():IQueriable<T>

\iQuarc\DataAccess

Isolate from external libraries

<<static class>>

Log

+LogError()+LogWarining()

Exception Wrappers Decorators

<<Interface>>

API Interfaces

25

Application Infrastructure – Shaping to Context

.NET Framework

WF

WCF

WEB API

ASP.NET

Entity Framework

. . . Unity

NServiceBus Log4Net

. . .

Application Infrastructure

Application Functionalities

When to do it?

cum

ula

tive

funct

ionalit

y

time

completion

construction

ready

design payoff

When to do it?cu

mula

tive

funct

ionalit

y

time

completion

construction

ready

design payoff

time

Arc

Arc

Infr

a

Funct

ionalit

yIn

fra Fu

nct

ionalit

yIn

fra

Funct

ionalit

y

Funct

ionalit

y

Funct

ionalit

y

Funct

ionalit

y

RepositoryImpl

+ GetEntities<T>() : IQueriable()

IRepository IUnitOfWork

+ SaveChanges()

IModule

<<Attribute>>

ServiceAttribute

\iQuarc

Funct

ionalit

y

Thank You!

Florin CorosPartner and Co-founder, iQuarc

florin.coros@iquarc.com

blog.iquarc.com/florin

@florincoros