Cloud

basheddockDéveloppement de logiciels

21 févr. 2014 (il y a 3 années et 6 mois)

96 vue(s)

Cloud Computing:

Towards Virtualized Service Platforms

Karim
Djemame

2

Outline


Towards a Definition of Cloud Computing


Grids and Clouds


Example of a Cloud Architecture


Cloud computing
-

Research Questions


The Service Oriented Infrastructure Equation


Interoperability


Dependability


Conclusion

Towards a Definition of Cloud Computing

4

Just to start … “Five
computers”


"I think there is a world market for about five computers"


Remark attributed to Thomas J. Watson (Chairman of the
Board of International Business Machines)


1943


Medium/Long Term Context


Future internet of services


World without computers at home and at work


World with virtual computers/networks


Various devices used to connect to the future internet of
services (e.g. only TV or iPhone and network)


Change


No more maintenance of IT infrastructure and
Applications/Data for users,


But,


Data is no longer on « your » computer


Applications are no longer on « your » computer

26/03/2009

5

Exploring Cloud Computing

6

Cloud computing


a Definition


Towards a definition of cloud computing


A Break in the Clouds: Towards a Cloud Definition. Luis M.
Vaquero et al. (January 2009)
provides
22 different
definitions


Cloud computing is an information technology
infrastructure in which computing resources are
virtualized

and accessed as a
service
.


"Cloud" will be a grand buzzword unifier in IT:


utility computing, Grid computing, software
-
as
-
a
-
service,
and many other scalable remote computing models will
get linked to cloud computing.

7

Cloud computing


a Definition (2)


Clouds are a large pool of easily usable and
accessible virtualised resources


These resources can be dynamically reconfigured to
adjust to a variable load (scale), allowing also for an
optimum resource utilisation


This pool of resources is typically exploited by a pay
-
per
-
use model in which guarantees are offered by
the infrastructure provider by means of customised
Service Level Agreements.

8

Today …


Service
-
Oriented economy is at our door


Services over the Internet are winning in the market


Consumers use YouTube, eBay, Amazon, …


SMEs use hosted Microsoft Exchange, Salesforce.com


Enterprises routinely rely on remote IT outsourcing


Services reduce complexity and cost


Cloud computing providers


Amazon, Google, Microsoft …


Service
-
Oriented Economy
requires

a Service
-
Oriented Infrastructure

9

The Vision

Physical
Layer

Virtualization
Layer

Service
Layer

Service

Manager

Service

User Layer

Grid Site

Service

End
-
user

Service

Admin.

Virtual Execution Environment Management System

Value Chain

Service

Consumer

Service

Provider

Infrastructure

Provider

Grids vs Clouds

11

Grids vs. Clouds

Feature

Grid

Cloud

Resource sharing

Collaboration (VOs)

Assigned resources not
shared

Virtualisation

Data and computing
resources

Hardware and software
platforms

Security

Credential delegations

Isolation

Architecture

SOA

User chosen

Software dependencies

Application domain
dependent

Application domain
independent

Platform awareness

Client SW must

be Grid
-
enabled

Customised

environment

Scalability

Nodes and sites

Nodes, sites, and
hardware

Centralisation

degree

Decentralised control

Centralised

Usability

Hard to manage

User friendly

QoS

guarantees

Limited support

Limited support



12

Usage Modes


General purpose Grids are typically constructed
bottom
-
up

aggregating existing heterogeneous
resources


Interfaces designed to provide combined functionality


Clouds constructed
top
-
down

with a limited, specific
set of use cases and modes


Interfaces are designed to support these and only these


Clouds can be built on top of Grids

13

Grids and Clouds

Portal

Example of a Cloud Architecture

15

Three Types of Systems


Infrastructure as a Service


Through virtualization,
infrastructure providers
are able to
split, assign and dynamically manage service Providers,
that will deploy on these systems the software stacks that
run their services


Platform as a Service


Instead of supplying a virtualized infrastructure, they can
provide the
software platform
where systems run on


Software as a Service


This is an alternative to locally run applications

16

Example: Amazon Web Services (AWS)


EC
2
(Elastic Computing Cloud) is the computing service of
Amazon


Based on hardware virtualisation (Xen)


Users request virtual machine instances, pointing to an image (public or
private)


Users have full control over each instance (e.g. access as root, if required)


Request can be issued via SOAP and REST


X
509
certificates


S
3
(Simple Storage Service) is a service for storing and accessing
data on the Amazon cloud


From a user’s point
-
of
-
view, S
3
is independent from the other Amazon
services


Data is built in a hierarchical fashion, grouped in containers and objects


Data is accessible via SOAP, REST and BitTorrent

17

Resources Virtualisation


Different virtual machines can run different operating
systems and multiple applications on the same
physical computer.


The main technology enabling virtualisation is the
Hypervisor


Virtual Machine Manager (VMM) that partitions a physical
host server transparently via emulation or hardware
-
assisted virtualisation


This provides a complete simulated hardware environment


Which Virtual Machine Manager? VMware, XEN…?


Types of virtualisation?

18

Examples of Cloud
Architectures


OpenNebula
: open source virtual infrastructure engine that
enables the dynamic deployment and re
-
placement of virtual
machines on a pool of physical resources


http://www.opennebula.org/


From the FP
7
RESERVOIR project http://www.reservoir
-
fp
7
.eu


Eucalyptus
: Elastic Utility Computing Architecture


links Programs to Useful Systems


an open
-
source software infrastructure for implementing "cloud
computing" on clusters


interface to Eucalyptus is compatible with Amazon's EC
2
interface


http://eucalyptus.cs.ucsb.edu/


Research Questions

20

The Service Oriented
Infrastructure (SOI) Equation


Integration of virtualization technologies with
Grid computing driven by new techniques for
Business Service Management (BSM)

=

SOI

Virtualization

-

Aware Grid

e

.

g

.

,

VM usage

/

size as the unit

for metering and billing

Grid

-

Aware Virtualization

e

.

g

.

,

live migration across

administrative domains

BSM

e

.

g

.

,

policy

-

based management

of service

-

level agreement

+

+

21

Cloud Interfaces

No middleware!!

Resource
-
side

Grid middleware?

22

Interoperability


Assuming that several cloud computing providers
come to be…


Which interface matter?


23

Standards


God loves standards: that’s why he made so many of
them



Since “simple is beautiful” …


if the proposed interfaces by cloud services like AWS are to become
popular with Grid users, they might change the standardisation
landscape


HTTP, REST, Xen and BitTorrent are already largely standardised


What is left at that level


REST access to storage


Virtual Image formats


Instantiation API (perhaps based on REST)


A reference open source implementation is missing

Risk Management Services in
Virtualized Service Platforms


Need for dependable services


Any time access for large but varying number of users


Service availability crucial


Risk assessment and management as basic service


Multiple stakeholder perspective


Users


Assess and select best services


Evaluate legal issues and sustainability


Trust for data security and confidentiality


Providers


Analyse, improve and maintain infrastructure


Compete to attract new users


Take all measures to ensure permanent service availability


Telcos


Compose and offer high quality services

26
/
03
/
2009

24

25

Conclusion


Existing Grids have an opportunity to lead the
next generation e
-
Infrastructure by integrating
new advancements such as cloud computing


Hardware virtualisation could lower the
operations cost of large infrastructures


Roadmap should be defined to include cloud
technology in current Grid Infrastructures in
an incremental and harmonious fashion

26

So… Five computers!


"I think there is a world market for about five computers"


Remark attributed to Thomas J. Watson (Chairman of the
Board of International Business Machines)


1943



“… In a sense, says Yahoo Research Chief Prabhakar Raghavan,
there are only five computers on earth
. He lists
Google, Yahoo,
Microsoft, IBM, and Amazon
. Few others, he says, can turn
electricity into computing power with comparable efficiency …”



27

a “Take Home” message:

Five computers?


"I think there is a world market for about five computers"


Remark attributed to Thomas J. Watson (Chairman of the
Board of International Business Machines)


1943



“… In a sense, says Yahoo Research Chief Prabhakar
Raghavan,
there are only five computers on earth
. He lists
Google, Yahoo, Microsoft, IBM, and Amazon
. Few others, he
says, can turn electricity into computing power with
comparable efficiency …”

From

Google and the wisdom of clouds
,
by Steven Baker
-

BusinessWeek.com



“… The World Wide Web is becoming one vast, programmable
machine. As NYU's Clay Shirky likes to say,
Watson was off by
four

…”



Nicholas Carr

From
Wired Magazine Q&A with Nicholas Carr