Cloud Computing & its

Applications
Course Code: SWE4004

Module 2
 Cloud Enabling Technology

Outline
• Data center technology
• Virtualization technology
• Web technology
• Multitenant technology
• Service technology.
 Data center technology

• A data center is a specialized IT infrastructure that houses

centralized IT resources, such as servers, databases, and software
systems.
• A data center is a physical facility that organizations use to
house their critical applications and data.
• A data center's design is based on a network of computing
and storage resources that enable the delivery of shared
applications and data.
• Key components of a data center design include routers,
switches, firewalls, storage systems, servers, and
application-delivery controllers.
 Concerned Issues

• Virtualization
• Standardization and Modularity
• Automation
• Remote Operation and Management
• High Availability
• Security-Aware, operation and Management
• Facilities
• Computing Hardware
• Storage Hardware
• Network Hardware
 Virtualization

• Data center consist of both physical and

virtualized IT resources.

• All the physical components are grouped

into single network

• The resource abstraction and control on

virtualization layer
 Virtualization in Data center

The common components

of a data center working
together to provide
virtualized IT resources
supported by physical IT
resources
 Standardization and Modularity

• Commodity Hardware with modular

architecture, aggregating multiple identical
building blocks of infrastructure

• Key requirements for reducing investment

and operational cost
 Automation

• Specialized platforms and tools are needed

• Resource Provisioning, configuration,

patching and monitoring

• Self-configuration and self-recovery

 Remote Operation and
Management

• Used for most of operational and

administrative tasks of IT resources

• Equipment handling and cabling or

hardware-level installation and maintenance
not controlled from remotely.
 High Availability

• Data center Outage significantly impacts IT

Services availability

• Higher levels of redundancy to sustain

availability
 Security-Aware, operation and
Management

• Ubiquitous access, on-demand provisioning

rapid elasticity and pay-per-use.

• Physical and logical access controls and

data recovery strategies.
 Facilities

• Computing, Storage and network equipment

• power, cabling, cooling, fire protection

 Computing Hardware

• Supports Different processing architectures like x86-32,x86-64

and RISC
• Power efficient multi-core CPU
• Redundant and hot-swappable components
 Storage Hardware

• Hard Disk Array: RAID

• I/O caching
• Storage Virtualization
• Fast Data Replication Mechanisms

Network Storage device

• storage area network(SAN)
• network attached storage(NAS)
Storage Hardware
NAS vs SAN
 Network Attached Storage

NAS Benefits
• Relatively inexpensive
• 24/7 and remote data availability
• Salability
• Redundant storage architecture
• Automatic backups to other devices and
cloud
• Flexibility
 Storage Area Network

SAN Benefits
• Extremely fast data access
• Dedicated network for storage relieves
stress on LAN
• Highly expandable
• OS level (block level) access to files
• High quality-of-service for demanding
applications such as video editing
 Network Hardware

• Carrier and External Networks

Interconnection

• Web-Tier Load Balancing and Acceleration

• LAN Fabric

• SAN fabric

• NAS Gateways
 Virtualization Technology

• Virtualization is the process of converting a physical IT

resources into virtual IT resources.
• Most types of IT resources can be virtualized:

• Servers: A physical server can be abstracted into a virtual server.

• Storage: A physical storage device can be abstracted into a virtual

storage device or a virtual disk.

• Network: Physical routers and switches can be abstracted into logical

network fabrics, such as VLANs.

• Power: A physical UPS and power distribution units can be abstracted into
what are commonly referred to as virtual UPSs
Physical v/s Virtual Machine
 Virtualization Platform

• A VM is an isolated runtime environment (guest OS and applications)

• Multiple virtual systems (VMs) to run on a single physical system

Applications Applications Applications

VM VM VM
Guest OS Guest OS Guest OS

Virtualization Platform (Xen, KVM, VMware…)

Physical Box

Benefits of Virtualization Platforms

• Natural way to deal with the heterogeneity of the infrastructure
• Allow partitioning and isolating of physical resources
• Execution of legacy applications
 Benefits of using Virtual
Machines

• Instant provisioning - fast scalability

• Live Migration is possible
• Load balancing and consolidation in a Data
Center is possible.
• Low downtime for maintenance
• Virtual hardware supports legacy operating
systems efficiently
• Security and fault isolation
 Virtualization Technology

• Hardware Independence
• Server Consolidation
• Resource Replication
• Operating System-Based Virtualization
• Hardwar-Based Virtualization
• Virtualization Management
• Other Considerations
 Hardware Independence

• Virtualization is a conversion process that translates

unique IT hardware into emulated and standardized
software-based copies.

• Through hardware independence, virtual servers

can easily be moved to another virtualization host,
automatically resolving multiple hardware-software
incompatibility issues.
 Server Consolidation

• Server consolidation is the practice of reducing

the number of servers or server locations in
order to use compute resources more efficiently
and reduce costs.

• This involves moving multiple, heterogeneous

workloads to a single server or combining
workloads under a single operating system.
Server Consolidation
 Resource Replication

• Resource replication is defined as the creation of

multiple instances of the same IT resource, and is
typically performed when an IT resource’s
availability and performance need to be enhanced.

• Virtual disk images can be accessible using simple

file operations, such as copy, move, and paste by the
host’s OS for replication purpose
 Operating System-Based
Virtualization
• Installation of virtualization software in pre-existing operating
system(Host)

• Host operating system responsible to provide hardware device

access

• Create more Virtual Servers

• Hardware independence is enabled

Operating System-Based
Virtualization

The different logical layer

of operating-system based
virtualization, in which the
VM is first installed into a
full host operating system
and subsequently used to
generate virtual machines
 Operating System-Based
Virtualization

Host operating system provide the following

services

• Backup and Recovery

• Integration to Directory Services
• Security Management
 Demands and issues

• Host operating system consumes CPU, Memory and

other hardware resources

• Virtual operating system instructions have to process

several layers

• Host operating requires individual licence

Hardware-Based Virtualization

• Bypass the host operating system

• With out host operating interaction, it allows virtual servers to

interact with hardware

• VMM require a negligible amount of storage

• VMM is a thin layer software

• Device drivers and system services are optimized

Hardware-Based Virtualization

The different logical

layers of hardware-
based virtualization,
which does not
require another host
operating system.
 Hardware-Based Virtualization

Issues of Hardware-based Virtualization

• Compatibility with hardware devices

• Device drivers may not be available

 Virtualization Management

• Many administrative task can be performed more

easily

• Modern virtualization software several advanced

management functions that can automate
administration tasks

• Virtualization infrastructure Management (VIM) tools

that collectively manage virtual resources
 Other considerations

• Performance overhead

• Special hardware compatibility

• Portability
 Best virtualization software

• VMware Workstation Player

• VirtualBox

• Parallels Desktop

• QEMU

• Citrix Hypervisor

• Xen Project

• Microsoft Hyper-V
 Web Technology

• Web technologies create interfaces between web servers and

clients, and insure safe usage of internet based applications and
permanent access to information.

• Cloud computing refers to internet-based computing systems

used to deliver applications between computers through the
internet.

• Cloud system users access computing services using web

browsers, which represents a computing model that shifts the
computing workload to a remote location.
Web Technology
Web Technology
Web Technology
Web Technology
 Web Technology

Communication protocols

• HTTP
• SMTP
• IP
Cloud delivery models
Private Cloud
 Web Technology

Basic Web Technology

• Uniform Resource Locator (URL)

• Hypertext Transfer Protocol (HTTP)

• Markup Language (HTML, XML)

 Web Applications

• Presentation layer (user interface)

• Application layer (application logic in

application server)

• Data layer (data store in data server)

 Web Applications

⚫ Figure 5.10 - The three basic architectural tiers of Web applications.

 Summery of Web Technology

• Web technology is very commonly for cloud service

implementations and for front-ends used to remotely
manage cloud-based IT resources.

• For instance, typical PaaS offerings have separate

instances of the Web server, application server, and data
server.

• Fundamental technologies of Web architecture

include the URL, HTTP, HTML, and XML.
 Multitenant Technology

• Multitenant – a single instance of an IT resource serves

multiple consumers (tenants).
• Multitenant application architecture is often
significantly more complex than that of single-tenant
applications.
• Multi-tenant applications need to support the sharing of
various artifacts by multiple users (including portals,
data schemas, middleware, and databases), while
maintaining security levels that segregate individual
tenant operational environments.
 Customize features

Tenants can individually customize features of the

application, such as:
• User Interface
• Business Process
• Data Model
• Access Control
Characteristics of Multitenant

• Usage isolation
• Data security
• Recovery
• Application upgrades
• Scalability
• Metered usage
• Data tier isolation
 Multitenancy

• Multitenancy is sometimes mistaken for virtualization

because the concept of multiple tenants is similar to the
concept of virtualized instances.
 Multitenant

A multitenant application
that is serving, multiple
cloud service, consumers
simultaneously
 Multitenancy VS.
Virtualization
The differences lie in what is multiplied within a physical
server acting as a host:
• With virtualization:
Multiple virtual copies of the server environment can be hosted by
a single physical server. Each copy can be provided to different
users, can be configured independently, and can contain its own
operating system and applications.
• With multitenancy:
A physical or virtual server hosting an application is designed to
allow usage by multiple different users. Each user feels as though
they have exclusive usage of the application.
Top Cloud Priority for
Enterprises
 Service Technology

Along with XML, the core technologies behind Web services are
represented by the following industry standards:

• Web Service Description Language (WSDL)

• XML Schema Definition Language (XML Schema)
• Simple Object Access Protocol (SOAP)
• Universal Description, Discovery, and Integration (UDDI)

Note that: These 4 technologies collectively form the first generation

of Web service technology. The 2 generation (WS-*) addresses
additional features, such as security, reliability, transactions, routing,
and business process automation.
WSDL
 WSDL Document

Element Description

<types> Defines the (XML Schema) data types used by the web service

<message> Defines the data elements for each operation

<portType> Describes the operations that can be performed and the messages
involved.

<binding> Defines the protocol and data format for each port type
 WSDL Operations

One-way: The operation can

receive a message but will not
return a response

Request-response:The operation
can receive a request and will
return a response

Solicit-response:The operation
can send a request and will wait
for a response

Notification: The operation can

send a message but will not wait
for a response
SOAP Mesage
 SOAP

• SOAP – Simple Object Access Protocol.

• SOAP relies heavily on XML, and together with schemas,

defines a very strongly typed messaging framework.

• Every operation the service provides is explicitly defined,

along with the XML structure of the request and response for
that operation.

• Each input parameter is similarly defined and bound to a type:

for example an integer, a string, or some other complex object.

• All of this is codified in the WSDL – Web Service Description

(or Definition, in later versions) Language.
SOAP Mesage
SOAP Request Mesage
 WSDL Binding to SOAP

An overview of how first-

generation Web service
technologies commonly
relate to each other
 REST Service and Service
Agents
• REST services are designed according to a set of constraints that
shape the service architecture to emulate the properties of the
WWW.

• Service agents are event-driven programs designed to intercept

messages at runtime, either active agent or passive agent.

• Falling under the umbrella of service technology is the large of

middle platform. Two main categories are the enterprise service bus
(ESB) and the orchestration platform.
REST v/s SOAP
Differences in SOAP and REST
 Summary of Service
Technology
• Web-based services such as Web services and REST services rely
on non-proprietary communications and technical interface
definitions to establish standardized communications frameworks
based on Web technology.

• Service agents provide event-driven runtime processing

that can be applied to numerous functional areas within
clouds.

• Service middleware, such as ESBs and orchestration platforms,

can be deployed on clouds.
 DTGOV Case Study

DTGOV has assembled cloud-aware infrastructures in each of its

data centers, which are comprised of the following
components:

• Tier-3 facility infrastructure, which provides redundant

configurations for all of the central subsystems in the data
center facility layer.

• Redundant connections with utility service providers that have

installed local capacity for power generation and water supply
that activates in the event of general failure.
 Cont..

• An internetwork that supplies an ultra-high bandwidth

interconnection between the three data centers through
dedicated links.

• Redundant Internet connections in each data center to multiple

ISPs and the .GOV extranet, which interconnects DTGOV with
its main government clients.

• Standardized hardware of higher aggregated capacity that is

abstracted by a cloud-aware virtualization platform.
 Cont..

• Physical servers are organized on server racks, each of which

has two redundant top-of-rack router switches (layer 3) that
are connected to each physical server.

• These router switches are interconnected to LAN core-

switches that have been configured as a cluster.

• The core-switches connect to routers that supply

internetworking capabilities and firewalls that provide network
access control capabilities.
 Cont..

• A view of the server network connections inside the DTGOV

data center.

• A view of the storage system network connections inside the

DTGOV data center.

• A view of how two data center are connected each other in

DTGOV
A view of the server
network connections
inside the DTGOV data
center.
A view of the storage system
network connections inside
the DTGOV data center.
 Greenlight Technology
Simplified
Server Consolidation

Server consolidation is a strategy to reduce the total number of

physical servers or server locations that an organisation requires.
The practice has been developed in response to the problem of
server sprawl, a situation in which multiple, underutilized servers
take up more space and consume more resources than can be
justified by their workload. Reducing the number of servers brings
down the associated costs with servers and compute resources for
an organisation. The more dense the consolidation, the higher the
ROI is for the migration and the sooner the cost benefit of
consolidation is realised.
 Case Study

• Our client is a software development company in the application of

handheld devices and industrial inventory management systems for
large freight companies, specialist firms, and warehouses. Their
existing IT systems had some virtualisation in place, along with
single purpose server blades and standalone servers for other
organisation needs.
• The systems had been over provisioned and the resources were
underutilised. Although virtualisation was already in place, they
were using SAN storage with limited extensibility and all the
existing hardware was out of warranty and in excess of 4 years in
age. The only cost effective solution was to migrate the environment
to new hardware with much greater performance, as well as
increased data density.
 Initial Requirement

• Our client had previously made a large investment in hardware

to run their operation; this hardware was aging and becoming
unreliable. With current generation hardware, it was
straightforward to have a similar level of resources on new
infrastructure.
 Existing hardware

• The existing hardware was a complex mix of physical

machines, server blades, and virtual machines that were
VMware based.

• In line with the customers objectives for the virtualization

project the decision was made to take the entire environment
and convert it to VMware virtual machines running on ESXi 5.

• The existing environment consisted of two racks of

equipment’s containing a fully populated HP Blade Centre, a
selection of older generation HP servers and older generation
SAN.
REST v/s SOAP
 New layout and hardware

By leveraging the performance and memory density

of the latest generation of Dell rack mount servers
we are able to condense the entire environment on
to a single two rack unit virtualisation host, which
was relocated into Global Switch and a single two
rack unit storage server for local file access located
in the office.

The new Dell server has redundant power supplies,

fault tolerant RAID arrays and accelerated cache for
optimal speed and redundancy.

We also redeployed one of the existing HP servers

to provide local replication of the file storage via
DFS. The previously slow and unstable VPN
connections that were coming into the office for
remote workers are now being terminated on the
Data Centre side on a Cisco ASA with SSL VPN’s
with significantly increased bandwidth and stability.
 The Conversion Process

• We leveraged the features in VMware converter

to convert the existing virtual machines and
physical machines to VMware virtual
machines.
• The conversion was done in a staggered fashion
outside of office hours to avoid interrupting
business operations.

• The VMware converter allows for machines to

be processed in batches, with a technician
working on Virtual Machine configuration
settings such as networking, then reconfiguring
each machines after the move. The migrations
are still ongoing in the background minimising
the time wastage of technicians sitting around
waiting for the conversions.
RESULT
Cont..
 Conclusion

• With the virtualization project now complete, our client is now

reaping the benefits of the consolidated infrastructure. Remote
workers now no longer suffer from bandwidth issues and,
applications hosted on the new infrastructure now run much
faster.
End of Module 2