What is Cloud Computing? How an application change with Cloud?

1. Principi del Cloud Computing e
migrazione delle applicazioni
moderne al cloud
Marco Parenzan
ITST Kennedy 2015 Edition

2. Marco Parenzan
Formazione & 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

3. 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

4. Spesa attuale

5. 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

6. 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

7. “Computation may someday
be organized as a public utility”
(John Mccarty, 1960s)

8. Computing: la quinta utility
 Acqua
 Gas
 Elettricità
 Telefono
 Computing

9. Introduzione al
Cloud Computing
Nuove abitudini

10. 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

11. 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

12. Cos’è il Cloud Computing
On-demand, scalable, multi-tenant, self-service compute and storage resources

13. 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 Technology
http://csrc.nist.gov/groups/SNS/cloud-computing/

14. 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

15. Fortune 500 using Azure
>57% >300k
Active websites
More than
1,000,000
SQL Databases in Azure
>30TRILLION
storage objects >300MILLION
AAD users
>13 BILLION
authentication/wk
>3
MILLION
requests/sec
>1.65MILLION
Developers registered
with Visual Studio Online

16. .NET Support2014
Offline Sync
Mobile Services
Networking Visual Studio & .NET
Virtual Machines
Memory Optimized Disk Optimized
Resource Manager
Portal
VSO GA
XamarinPoint-to-site VPN
Web Sites
SMB File System
IBIZA
Remote Debug
VM Managemen
SQL Database
Puppet Chef Docker
Powershell and DSC
Capture / Deploy
Autoscale
Dynamic 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 Debugging
Kindle Support
BD’s up to 500GB
99.95% SLA
Self Service Site Recovery
Active 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

17. Compliance: aka.ms/AzureCompliance

18. Visual Studio Online
 Full Portal Integration
 Not just for Microsoft shops
Agile
Build Test
Deploy
InsightsCode

19. 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

20. Service Models in Cloud

21. 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).

22. Percorso attraverso i modelli di
distribuzione

24. On Premises
Youscale,makeresilientandmanage
Infrastructure
(as a Service)
Storage
Servers
Networking
O/S
Middleware
Virtualization
Data
Applications
Runtime
Managedbyvendor
Youscale,make
resilient&manage
Platform
(as a Service)
Scale,resilienceand
managementbyvendor
Youmanage Storage
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
Scale,resilienceand
managementbyvendor
Why the cloud?

25. Iaas, Paas, Saas Comparison

26. 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

27. Service Models in Microsoft Azure

28. 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
Blob
Storage
Comprehensive
Networking
Windows Server
Linux
Boot VM from new disk

29. 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

30. 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

31. Services for Applications in Cloud

32. 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.

33. 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

34. 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

35. 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

36. 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

37. Services for Applications in Azure

38. Support for Open Source
Languages
CMS
Devices
Databases /
Apps
Operating
systems
Management

39. Scalability Scenario

40. 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.

41. 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

42. 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

43. Managing demand
Don’t forget you are also paying for unnecessary software licencing while you are over capacity
TIME
ITCAPACITY
Actual Load
Allocated
IT-capacities
Too Much
Power
Load Forecast
Potential
business loss
Wasted
capacity
Not Enough Power

44. Predictable Bursting
Services with no seasonality trends
No particular peaks
IT complexity, no wasted capacity
Uso «sostanzialmente» costante
Applicazioni interne

45. 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

46. 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

47. 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

48. 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

49. Async to scale?
It depends…

50. (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 SideAsyncronous is for responsiveness
 Server SideAsyncronous 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

51. “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

52. A queue to scale

53. 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

54. 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
 …

55. 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

56. 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
Command
Command
Command
Command
Command
Command
Command Queue

57. A worker to scale

58. 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 commandsmany command handlers

59. 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

60. 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

61. An event to scale

62. 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

63. 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
Event
Event
Event
Event
Event
Event
Event Queue
Listener
Listener
Listener
Listener

64. Push data on the web

65. 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

66. 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

67. 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