Principi del Cloud Computing e

migrazione delle applicazioni

moderne al cloud

Marco Parenzan

ITST Kennedy 2015 Edition

Marco ParenzanFormazione & Divulgazione con 1nn0va

Microsoft MVP 2014 for Microsoft Azure

Formazione & Progettazione con ITS Kennedy

Ricerca e Innovazione con Servizi Cgn

www.slideshare.net/marco.parenzan

marco [dot] parenzan [at] libero [dot] it

www.innovazionefvg.net

Developer e Architect in .NET e Web

Cloud Developer

Loves functional programming

Some videogames for fun

Alcuni termini

Hosting è l’esecuzione di una soluzione applicativa su un server di produzione

Hosting on premise è l’hosting «in casa propria»

Il deployment è l’attività di installazione della soluzione applicativa sull’hosting

Spesa attuale

Alcune cattive abitudini

Non calcolare il ritorno economico della messa in produzione di una soluzione applicativa

Non calcolare il costo operativo di una soluzione applicativa

Pensare che i costi siano fissi

Pensare che decisa una volta (all’inizio) la scelta sia per sempre

Pensare che una soluzione applicativa giri su una sola macchina

Una discussione

Il costo del telefono e della connettività Internet sono fissi

I costi di acqua, luce e gas sono variabili (eppure la manutenzione di una rete acqua,

luce e gas è arbitrariamente straordinaria – se non si rompe...)

Qualsiasi infrastruttura ha bisogno di manutenzione

La manutenzione sulla rete telefonica e dati è sempre straordinaria

La manutenzione di un server è ordinaria

“Computation may someday

be organized as a public utility”

(John Mccarty, 1960s)

Computing: la quinta utility

Acqua

Gas

Elettricità

Telefono

Computing

Introduzione al

Cloud Computing

Nuove abitudini

Obiettvi

Ridurre gli investimenti IT per l’Impresa

Variabilizzare i costi, rendendoli certi

Ridurre la necessità di investire in competenze interne per la gestione dell’infrastruttura e

l’aggiornamento del software

Nuove abitudini

Avere sempre un business plan

I costi sono variabili (ma questo non significa che la spesa non sia predicibile – bisogna

saperlo fare)

Bisogna adattare le scelte fatte in corso d’opera

Una soluzione applicativa deve poter girare su più macchine

Cos’è il Cloud Computing

On-demand, scalable, multi-tenant, self-service compute and storage resources

Cos’è il Cloud Computing

Il Cloud Computing è un modello che consente una convenienza attraverso l’accesso

(on-demand) ad una rete condivisa di un pool di risorse di calcolo configurabili (ad

esempio, network, server, storage, applicazioni e servizi) che possono essere rapidamente

fornite e rilasciate con il minimo sforzo di gestione o con interazione del service provider.

Questo modello di Cloud promuove la disponibilità ed è composto da cinque

caratteristiche fondamentali, tre modelli di servizio, e quattro modelli di distribuzione..

NIST v15 – 07/10/2009

NIST - National Institute of Standards and Technologyhttp://csrc.nist.gov/groups/SNS/cloud-computing/

Cloud Computing appetibile

Disponibilità ovunque

Rapidità di implementazione

Facilità di utilizzo

Aggiornamento costante del software

Scalabilità della soluzione con la

crescita e la variabilità della

domanda

Riduzione dei costi

Fortune 500 using Azure

>57% >300kActive websites

More than

1,000,000SQL Databases in Azure

>30TRILLIONstorage objects >300 MILLION

AAD users

>13 BILLIONauthentication/wk>3

MILLIONrequests/sec

>1.65MILLIONDevelopers registered

with Visual Studio Online

.NET Support2014Offline Sync

Mobile Services

Networking Visual Studio & .NET

Virtual MachinesMemory Optimized Disk Optimized

Resource Manager

Portal

VSO GA

XamarinPoint-to-site VPN

Web Sites

SMB File SystemIBIZA

Remote Debug

VM Management

SQL Database

Puppet Chef DockerPowershell and DSC

Capture / Deploy

AutoscaleDynamic Routing

Subnet Routing

Static IP

Storage

Autoscale

Traffic Mgr

Web Jobs

Backup

Java Support

ASP.NET MVC 5.1

ASP.NET Web API 2.1

AD support

Powershell Automation

Node.JS project support

Remote DebuggingKindle Support

BD’s up to 500GB

99.95% SLA

Self Service Site RecoveryActive GEO replication

HDInsight

Hadoop 2.2

YARN support

.NET 4.5

.NET Foundation

Azure Redis Cache

API Management

Site Recovery

Remote Apps

Cordova

VSO Open Api’s

Event Hub

Compliance: aka.ms/AzureCompliance

Visual Studio Online

Full Portal Integration

Not just for Microsoft shops

Agile

Build Test

Deploy

InsightsCode

Key Scenarios to get started with Microsoft

Azure

Dev / Test

Full test and dev environments in minutes

VSO integration

Lift and Shift

Take existing work loads and run then in a certified instance

Storage

Archive key data in inexpensive cloud storage

Big Data

Process key data into business intelligence using Hadoop or Machine Learning

Identity

Synchronize all your identities through Azure AD to control access to Apps, Data and Services

Web Apps

Take your web apps to the cloud using inexpensive Web Sites

Service Models in Cloud

Modello di distribuzione

La cloud infrastructure è di

proprietà di una

organizzazione che vende i

servizi cloud al pubblico o

ad un gruppo di grandi

imprese

L’infrastruttura è una

composizione di due o più

cloud (private, community, o

public) in una entità unica,

tenute insieme da

tecnologie proprietarie tali

da permettere la portabilità

dei dati e delle applicazioni

(ad esempio, cloud

bursting).

La cloud infrastructure è di

proprietà o in leasing di una sola

organizzazione ed è utilizzata

esclusivamente

dall'organizzazione

La cloud infrastructure

è condivisa da diverse

organizzazioni e sostiene

una comunità specifica

che ne condivide degli ambiti

(ad esempio, la mission, i

requisiti di sicurezza, la policy, e

le considerazioni di conformità).

Percorso attraverso i modelli di distribuzione

On Premises

Yo

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Infrastructure(as a Service)

Storage

Servers

Networking

O/S

Middleware

Virtualization

Data

Applications

Runtime

Man

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Platform (as a Service)

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Yo

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eStorage

Servers

Networking

O/S

Middleware

Virtualization

Applications

Runtime

Data

Hosting models

Software(as a Service)

Storage

Servers

Networking

O/S

Middleware

Virtualization

Applications

Runtime

Data

Business model

Storage

Servers

Networking

O/S

Middleware

Virtualization

Data

Applications

Runtime

Sca

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Why the cloud?

Iaas, Paas, Saas Comparison

Modello di servizio

(SaaS). Fornisce al consumatore la possibilità di usare le applicazioni in esecuzione

su una Cloud infrastructure accessibile da vari dispositivi client attraverso una

interfaccia come un browser Web (ad esempio, una web-based e-mail). Il

consumatore non riesce a controllare l’ infrastruttura base della Cloud, rete, server,

sistemi operativi, storage, con la possibile eccezione di limitate specifiche

impostazione per l'utente delle impostazioni di configurazione dell’applicazione.Application

Platform

(PaaS). Fornisce al consumatore la possibilità di distribuire nella Cloud infrastructure

applicazioni create dal consumatore che utilizzano linguaggi di programmazione

supportati dal fornitore (ad esempio, Java, Python,. Net). Il consumatore non ha il

controllo della base della Cloud infrastructure, rete, server, sistemi operativi, storage,

ma ha il controllo sulle applicazioni distribuite ed eventualmente sulle configurazioni

dell’ ambiente.

(IaaS). Fornisce al consumatore il poter noleggiare capacità di CPU, storage,

network, e altre risorse fondamentali che il consumatore è in grado di implementare

e gestire, che possono includere i sistemi operativi e le applicazioni. Il consumatore

non ha il controllo delle infrastruttura di base della Cloud, ma ha il controllo su

sistemi operativi, storage, la distribuzione delle applicazioni, ed eventualmente

selezionare componenti di rete (ad esempio, firewall, load balancer).Infrastructure

Service Models in Microsoft Azure

Virtual Machines

Getting started

>_

REST API

Management portal

Scripting (Windows, Linux and Mac)

Select image and VM size

Extra Small

Small

Medium

Large

X-Large

New disk persisted in storage

Cloud

BlobStorage

Comprehensive Networking

Windows Server

Linux

Boot VM from new disk

Microsoft Azure Web Sites

Create new sites in seconds

Easily manage and scale your sites

Automatic load balancing and shared

storage across instances

Scale out or up to reserved instances

for improved performance and scale

Built-in web jobs support

Use ASP.NET, ASP, PHP, Java or

Node.js

SQL Azure or MySQL databases

Start with open source apps and

frameworks

Develop with VS and WebMatrix

Supports any Web development

tool on any platform (Windows,

OSX, Linux)

Rapid deployment for quick

iteration

Integrated source control with

Team Foundation Server (TFS) and

Git

Built-in monitoring of perf and

usage data

Quick access to request logs, failed

requests diagnostics and

diagnostics

Mobile Services

Storage

Authentication

Logic

Push

Scheduler

• Provides essential services to support client development

• Client Support• iOS

• Android

• HTML5/Web

• Xamarin

• Windows

• Windows Phone

• PhoneGap

• Sencha

Services for Applications in Cloud

On-demand self-service

Broad network access

Resource pooling

Measured Service

Rapid elasticity

On Demand Self Service

Il Consumatore può disporre di capacità di calcolo (es. server time, network storage) se

necessario senza richiedere l’interazione umana con alcun fornitore del servizio.

Il servizio è completamente automatizzato e permette di modificare la richiesta a

seconda delle volontà del consumatore.

Broad Network Access

Le capacità sono disponibili in rete ed accessibili in qualsiasi momento tramite Pc, Laptop

ma anche altri strumenti che possono accedere ad Internet come Cellulari, Palmari ecc…

Broad network access

Resource pooling

Measured Service

Rapid elasticity

On-demand self-service

Resource Pooling

Le risorse di calcolo sono messe al servizio di tutti i consumatori utilizzando un modello

MULTITENANT, che permette ad un’istanza Software di servire più Client, con diverse risorse

fisiche e virtuali dinamicamente riassegnate in base alla domanda dei consumatori.

L’Utente in genere non ha controllo/conoscenza dell’esatta posizione delle risorse (in

alcuni casi può essere un problema).

Broad network access

Resource pooling

Measured Service

Rapid elasticity

On-demand self-service

Measured Service

I Sistemi Cloud automaticamente controllano e ottimizzano le risorse misurandole

adeguatamente.

L’utilizzo è misurato per offrire un servizio “Pay-per-Use”. L’utente paga per il servizio che

realmente utilizza.

Broad network access

Resource pooling

Measured Service

Rapid elasticity

On-demand self-service

Rapid Elasticity

Le Risorse possono essere rapidamente ed elasticamente incrementate per scalare la

potenza ed essere allo stesso modo rilasciate.

Per il consumatore le capacità delle risorse disponibili spesso sembrano “infinite” e può

acquistarne qualsiasi quantità in qualsiasi momento.

Broad network access

Resource pooling

Measured Service

Rapid elasticity

On-demand self-service

Services for Applications in Azure

Support for Open Source

Languages

CMS

Devices

Databases / Apps

Operatingsystems

Management

Scalability Scenario

Scalability

From Wikipedia

Scalability is the ability of a system, network, or process to handle a growing amount of work in a

capable manner or its ability to be enlarged to accommodate that growth

In another way

Scalability describes the ability to keep constant the handling time of a request as amount of

work growth.

Ways to manage scalability

Scaling Up

Get it bigger

Be carefull about single points of failure

Scaling Out

Get it more that one

Be careful about state

Async

Give it the right time

Decoupling in time

Queuing

Decoupling in tiers

Scaling

Scale up by choosing different VM sizes

Scale out by adding more instances

Scale-out automatically with Elastic scaling

Scale out static content with CDN to distribute user traffic

Scale out low-variable data with caching to offset server workloads

Managing demand

Don’t forget you are also paying for unnecessary software licencing while you are over capacity

TIME

IT C

AP

AC

ITY

Actual Load

Allocated

IT-capacities

Too Much

Power

Load Forecast

Potential business loss

Wasted capacity

Not Enough Power

Predictable Bursting

Services with no seasonality trends

No particular peaks

IT complexity, no wasted capacity

Uso «sostanzialmente» costante

Applicazioni interne

Unpredictable Bursting

Marketing On-Time Offer

Aperiodical Dues

Special Event

Unexpected/unplanned peak in demand

Sudden spike impacts performance

Can’t over provision for extreme cases

Average Usage

Periodical Bursting

Marketing Periodical Offer

Periodical Dues

Special Repeatable Events

Services with micro seasonality trends

Peaks due to periodic increased demand

IT complexity and wasted capacity

On/Off Bursting

Digital media rendering and encoding

Financial and insurance risk calculation

Engineering modeling and simulation

Computational life sciences

Earth sciences

Data analytics

On & off workloads (e.g. batch job)

Over provisioned capacity is wasted

Time to market can be cumbersome

Growing Fast

Social Media

Web Games

Successful services needs to grow/scale

Keeping up w/ growth is big IT challenge

Cannot provision hardware fast enough

Average Usage

Async to scale?

It depends…

(A)Syncronous

Syncronous (relation) between a client and a server is when server MUST respond to client

request and client have to wait ACTIVELY for server response.

Asyncronous, in a web context has two situations

Client SideAsyncronous is for responsiveness

Server SideAsyncronous is for scalability

Responsiveness

Don’t block UI thread so user can continue interacting with app while request is currently running

Scalability

Increase the usage of the thread pool while a request is blocked for I/O

“Async” scale-up

Sync cause “scaling up”

You can only increase resources because “sync” scenario tends to “lock” resources

Async lower the need of scaling up

Resources are better used

Async is not useful to scale out

A queue to scale

Let command be executed to whom is

really responsible

Async client

Responsive

Async server (MVC action)

Scalable

‘Still synchronous when executed by MVC role

MVC is “front end” role to the client

Syncronous implies “give a response”

Really?

It’s really needed

Response vs. “acknowledge”

Syncronization is needed to obtain an answer

What’s in the answer?

Result

Acknowledge

Result

What you expected from execution of the request

Acknowledge

Response about “taking responsibility” on request, but not the result

Why not the result

Typically because it take too long to obtain response

Async (client/server) is always “pretend an answer” inside a timeout ….in seconds on average

Many scenarios cannot have this

Order management

Interop with legacy systems

…

Command as a serializable request

Command is the metaphor for the request

Useful to be serializable

Serializable is useful to store/persist/”suspend”

Why “suspend”?

Because a long time to execute

Executor is overloaded

Executor is doing something else

Executor need it’s time to execute

Where serializing?

Somewhere where “taking out” is a principle

For example “FIFO” structures: queues

Using Queues

Queue are useful to receive commands

MVP frontend role just acquire commands

Commands are syntactically validated

Commands are just queued

(a)sync response from frontend is quick

Just acknowledge the insertion of command into

queue

MVC

Frontend

Role

Controller

ActionCommand Command

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Command Queue

A worker to scale

Commands in a queue

When Commands are in queue, who take commands out?

Command Handler is the generic concept

A CH handle a command

Many commandsmany command handlers

Domain in the CH

Command Handlers execute command

Act on the domain

Call aggregate entity methods

Mapping command parameters

Typically Commands are not domain objects

Workers

A command handler must be hosted in a process

Process are typically NON-UI processes

simple, Light

end-less (infinite loop)

Sleepy (suspend themselves each loop)

Stateless (no global variables, just loop function)

Horizontally scalable (execute many in parallel, in the same machine, in many machines)

Typically Console.exe apps (in .NET)

Estract message from queue and execute it

Support

Retry logic

Priority logic

An event to scale

Don’t take more responsibility: inform

about what you have done

A worker is the identity that implements CH and act on then domain

A worker knows the domain through aggregates

Aggregate know only its domain

What about impacts about acting on the domain?

Copies of data somewhere else

Perform other actions into other domain

Have the aggregate knowledge about effected?

No

Aggregate must declare that Something has happened

An event

An event is the knowledge of something happened in the history

An event must be shared with anyone

…interested about event

Event queue

Events generated by aggregate must be

collected in a structure that shares event

to many

Publisher/subscriber pattern

Many listener “subscriibe” to the event

queue

A subscriber declare which messages are

interesting

Aggregate

Method

1 Event

Ev

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Event Queue

Listener

Listener

Listener

Listener

Push data on the web

Responses: where are they

Client have done a request/a command

Client have received an acknowledge

Domain has executed the command

A result have happened…yes….?!?!?!?

A result is the execution of the command

A result is found

When? When event is notified

Where? Event give all and enough information to RETRIEVE the result, not the result itself

Client knows following the event which is the result to be retrieved

Pull/Push communication with client

How client knows about events?

Pull way

Client request from an event queue if it have and event

Events must be stored

Client have to query events queue to check if there are some new events

Push way

Server will reach client and send it an event message

Modern way with Web Sockets (in a Web scenario)

SignalR in ASP.NET

Retrieve the result

Event contains information to retrieve the result, not the result itself

Some keys, ids

Some display data

Event is a DTO

Event is enough to get other DTOs, for example

Event can be used to trigger other actions