ISSUES IN CLOUD COMPUTINGISSUES IN CLOUD COMPUTING

Flow of presentation : Flow of presentation :

IntroductionIntroduction

Security issuesSecurity issues

Data issuesData issues

Performance issuesPerformance issues

Energy related issuesEnergy related issues

Bandwidth related issuesBandwidth related issues

Fault toleranceFault tolerance

Conclusion Conclusion

WHAT IS CLOUD COMPUTING?WHAT IS CLOUD COMPUTING?

Cloud computing means using multiple server computers via a Cloud computing means using multiple server computers via a digital network, as though they were one computer. digital network, as though they were one computer.

We can say , it is a new computing paradigm, involving data and/or We can say , it is a new computing paradigm, involving data and/or computation outsourcing, withcomputation outsourcing, with

– – Infinite and elastic resource scalabilityInfinite and elastic resource scalability

– – On demand “just-in-time” provisioningOn demand “just-in-time” provisioning

– – No upfront cost … pay-as-you-goNo upfront cost … pay-as-you-go

The name cloud computing was inspired by the cloud symbol that's The name cloud computing was inspired by the cloud symbol that's often used to represent the Internet in flowcharts and diagrams.often used to represent the Internet in flowcharts and diagrams.

BENEFITSBENEFITS

Traditionally, without a cloud, a web server runs as a single computer or a Traditionally, without a cloud, a web server runs as a single computer or a group of privately owned computers group of privately owned computers

If the computer's website or web application suddenly becomes more If the computer's website or web application suddenly becomes more popular, and the amount of requests are far more than the web server can popular, and the amount of requests are far more than the web server can handle, the response time of the requested pages will be increased due to handle, the response time of the requested pages will be increased due to overloading. On the other hand, in times of low load much of the capacity overloading. On the other hand, in times of low load much of the capacity will go unused.will go unused.

If the website, service, or web application is hosted in a cloud, however, If the website, service, or web application is hosted in a cloud, however, additional processing and compute power is available from the cloud additional processing and compute power is available from the cloud provider. provider.

If the website suddenly becomes more popular, the cloud can If the website suddenly becomes more popular, the cloud can automatically direct more individual computers to work to serve pages for automatically direct more individual computers to work to serve pages for the site, and more money is paid for the extra usage. If it becomes the site, and more money is paid for the extra usage. If it becomes unpopular, however, the amount of money due will be less. unpopular, however, the amount of money due will be less. Cloud Cloud computing is popular for its pay-as-you-go pricing model.computing is popular for its pay-as-you-go pricing model.

In the past computing task there were not possible without the In the past computing task there were not possible without the installation of application software on a user's computer. A user installation of application software on a user's computer. A user bought a license for each application from a software vendor and bought a license for each application from a software vendor and obtained the right to install the application on one computer system.obtained the right to install the application on one computer system.

With the development of local area networks (LAN) and more With the development of local area networks (LAN) and more networking capabilities, the client-server model of computing was networking capabilities, the client-server model of computing was born, where server computers with enhanced capabilities and large born, where server computers with enhanced capabilities and large storage devices could be used to host application services and data storage devices could be used to host application services and data for a large workgroup. for a large workgroup. 

Difference between client-server and Difference between client-server and cloud computing :cloud computing :

Typically, in client-server computing, a network-friendly Typically, in client-server computing, a network-friendly client client version of the application is required on client computersversion of the application is required on client computers which which utilized the client system's memory and CPU for processing. even utilized the client system's memory and CPU for processing. even though resultant application data files were stored centrally on the though resultant application data files were stored centrally on the data servers. Multiple user licenses of an application were data servers. Multiple user licenses of an application were purchased for use by many users on a network.purchased for use by many users on a network.

Cloud computing differs from the classic client-server model by Cloud computing differs from the classic client-server model by providing applications from a server that are executed and managed providing applications from a server that are executed and managed by a client's web browser, with no installed client version of an by a client's web browser, with no installed client version of an application required.application required.

ArchitectureArchitecture

The two most significant components of cloud computing architecture are known as

the front end & the back end.

The front endThe front end is the part seen by the client, i.e., the computer user. is the part seen by the client, i.e., the computer user. This includes the client’s network (or computer) and the applications This includes the client’s network (or computer) and the applications used to access the cloud via a user interface such as a web used to access the cloud via a user interface such as a web browser. browser.

The back endThe back end of the cloud computing architecture is the cloud itself, of the cloud computing architecture is the cloud itself, comprising various computers, servers and data storage devices.comprising various computers, servers and data storage devices.

Cloud architecture, the systems architecture of the software Cloud architecture, the systems architecture of the software systems involved in the delivery of cloud computing, typically systems involved in the delivery of cloud computing, typically involves multiple cloud components communicating with each other involves multiple cloud components communicating with each other over loose coupling mechanism such as messaging queue.over loose coupling mechanism such as messaging queue.

Data storageData storage

Cloud storage is a model of networked computer data Cloud storage is a model of networked computer data storage where data is stored on multiple virtual servers, in general storage where data is stored on multiple virtual servers, in general hosted by third parties, rather than being hosted on dedicated hosted by third parties, rather than being hosted on dedicated servers. servers. 

Hosting companies operate large data centers; and people who Hosting companies operate large data centers; and people who require their data to be hosted buy or lease storage capacity from require their data to be hosted buy or lease storage capacity from them and use it for their storage needs. them and use it for their storage needs.

The data center operators, in the background, virtualizes the The data center operators, in the background, virtualizes the resources according to the requirements of the customer and resources according to the requirements of the customer and expose them as virtual servers, which the customers can expose them as virtual servers, which the customers can themselves manage. In the physical sense, the resource may span themselves manage. In the physical sense, the resource may span across multiple servers.across multiple servers.

Cloud computing services are broadly Cloud computing services are broadly divided into three categories:divided into three categories:

Infrastructure as a Service (IaaS)Infrastructure as a Service (IaaS) : :

This is the base layer of the cloud stack. It serves as a foundation This is the base layer of the cloud stack. It serves as a foundation for the other two layers, for their execution. The keyword behind this for the other two layers, for their execution. The keyword behind this stack is Virtualization. stack is Virtualization.

your application will be executed on a virtual computer (instance). your application will be executed on a virtual computer (instance). You have the choice of virtual computer, where you can select a You have the choice of virtual computer, where you can select a configuration of CPU, memory & storage that is optimal for your configuration of CPU, memory & storage that is optimal for your application.application.

The whole cloud infrastructure viz. servers, routers, hardware based The whole cloud infrastructure viz. servers, routers, hardware based load-balancing, firewalls, storage & other network equipments are load-balancing, firewalls, storage & other network equipments are provided by the IaaS provider. provided by the IaaS provider. Some common examples are Amazon, GoGrid, 3 Tera, etc.Some common examples are Amazon, GoGrid, 3 Tera, etc.

Platform as a Service (PaaS)Platform as a Service (PaaS)

Here, a layer of software, or development environment is Here, a layer of software, or development environment is encapsulated & offered as a service, upon which other higher levels encapsulated & offered as a service, upon which other higher levels of service can be built. of service can be built.

The customer has the freedom to build his own applications, which The customer has the freedom to build his own applications, which run on the provider‟s infrastructure. run on the provider‟s infrastructure.

To meet manageability and scalability requirements of the To meet manageability and scalability requirements of the applications, PaaS providers offer a predefined combination of OS applications, PaaS providers offer a predefined combination of OS and application servers.and application servers.

such as LAMP platform (Linux, Apache, MySql and PHP), Google‟s such as LAMP platform (Linux, Apache, MySql and PHP), Google‟s App Engine, Force.com, etc are some of the popular PaaS App Engine, Force.com, etc are some of the popular PaaS examplesexamples

Software as a Service (SaaS)Software as a Service (SaaS)

In this model, a complete application is offered to the customer, as a In this model, a complete application is offered to the customer, as a service on demand. A single instance of the service runs on the service on demand. A single instance of the service runs on the cloud & multiple end users are serviced.cloud & multiple end users are serviced.

On the customers‟ side, there is no need for upfront investment in On the customers‟ side, there is no need for upfront investment in servers or software licenses, while for the provider, the costs are servers or software licenses, while for the provider, the costs are lowered, since only a single application needs to be hosted & lowered, since only a single application needs to be hosted & maintained.maintained.

Today SaaS is offered by companies such as Google, Salesforce, Today SaaS is offered by companies such as Google, Salesforce, Microsoft, etc.Microsoft, etc.

DEPLOYMENT MODELSDEPLOYMENT MODELS

Private cloud:Private cloud: The cloud infrastructure is owned or leased by a single The cloud infrastructure is owned or leased by a single

organization and is operated solely for that organization.organization and is operated solely for that organization.

Community cloud: Community cloud: The cloud infrastructure is shared by several The cloud infrastructure is shared by several

organizations and supports a specific community that has shared organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy).concerns (e.g., mission, security requirements, policy).

Public cloud: Public cloud: The cloud infrastructure is owned by an organization selling The cloud infrastructure is owned by an organization selling

cloud services to the general public or to a large industry group.cloud services to the general public or to a large industry group.

Hybrid cloud:Hybrid cloud: The cloud infrastructure is a composition of two or more The cloud infrastructure is a composition of two or more

clouds that remain unique entities but are bound together by clouds that remain unique entities but are bound together by standardized orproprietary technology.standardized orproprietary technology.

ISSUES IN CLOUD COMPUTINGISSUES IN CLOUD COMPUTING

Security issues Security issues - Physical security - Physical security

- Operational security- Operational security

- Programmatic security- Programmatic security

Data issuesData issues - Data backup- Data backup

- Data usage- Data usage

- Data loss- Data loss

- Data integrity- Data integrity

- Data theft- Data theft

Performance issuePerformance issue

Design issuesDesign issues - Energy management- Energy management

- Novel cloud architectures- Novel cloud architectures

- Software Licensing- Software Licensing

ReliabilityReliability   

Legal issuuesLegal issuues - The Physical Location of your Data- The Physical Location of your Data

- Responsibility of your Data- Responsibility of your Data

- Intellectual Property Rights- Intellectual Property Rights

SECURITY ISSUESSECURITY ISSUES

Security is generally perceived as a huge issue for the cloudSecurity is generally perceived as a huge issue for the cloud

The survey found that while 58 percent of the general population The survey found that while 58 percent of the general population and 86 percent of senior business leaders are excited about the and 86 percent of senior business leaders are excited about the potential of cloud computing, potential of cloud computing, more than more than 90 percent of these same people are concerned about the 90 percent of these same people are concerned about the security, access and privacy of their own data in security, access and privacy of their own data in the cloud.the cloud.

There is a possibility where a malicious user can penetrate the There is a possibility where a malicious user can penetrate the cloud by impersonating a legitimate user, there by infecting the cloud by impersonating a legitimate user, there by infecting the entire cloud thus affecting many customers who are sharing the entire cloud thus affecting many customers who are sharing the infected cloud.infected cloud.

Security Is the Major ChallengeSecurity Is the Major Challenge

Some of the security problem which is faced by the Cloud Some of the security problem which is faced by the Cloud computing,computing,

Data IntegrityData Integrity

When a data is on a cloud anyone from any location can access those When a data is on a cloud anyone from any location can access those data’s from the cloud. Cloud does not differentiate between a sensitive data data’s from the cloud. Cloud does not differentiate between a sensitive data from a common data thus enabling anyone to access those sensitive data’s. from a common data thus enabling anyone to access those sensitive data’s. Thus there is a lack of data integrity in cloud computingThus there is a lack of data integrity in cloud computing

Data TheftData Theft

Most of the cloud Vendors instead of acquiring a server tries to lease a Most of the cloud Vendors instead of acquiring a server tries to lease a server from other service providers because they are cost affective and server from other service providers because they are cost affective and flexible for operation.flexible for operation.

The customer doesn’t know about those things, there is a high The customer doesn’t know about those things, there is a high possibility that the data can be stolen from the external server by a malicious possibility that the data can be stolen from the external server by a malicious user.user.

Security on Vendor levelSecurity on Vendor level Vendor should make sure that the server is well secured from all Vendor should make sure that the server is well secured from all

the external threats it may come across. A Cloud is good only when there is the external threats it may come across. A Cloud is good only when there is a good security provided by the vendor to the customers.a good security provided by the vendor to the customers.

Security on User levelSecurity on User level Even though the vendor has provided a good security layer for the Even though the vendor has provided a good security layer for the

customer, the customer should make sure that because of its own action, customer, the customer should make sure that because of its own action, there shouldn’t be any loss of data or tampering of data for other users who there shouldn’t be any loss of data or tampering of data for other users who are using the same Cloud.are using the same Cloud.

Information SecurityInformation Security Security related to the information exchanged between different Security related to the information exchanged between different

hosts or between hosts and users. This issues pertaining to hosts or between hosts and users. This issues pertaining to secure secure communicationcommunication, , authenticationauthentication, and issues , and issues concerning concerning single sign onsingle sign on and and delegationdelegation..

THERE MAY BETHERE MAY BE

Physical security : Physical security :

-- Physical location of data centers; protection of data centers Physical location of data centers; protection of data centers against disaster and intrusion.against disaster and intrusion.

How much safe is data from Natural disaster?How much safe is data from Natural disaster?

- Data can be redundantly store in multiple physical location.- Data can be redundantly store in multiple physical location.

- Physical location should be distributed across world.- Physical location should be distributed across world.

Data LocationData Location

- - When user use the cloud, user probably won't know exactly where your When user use the cloud, user probably won't know exactly where your data is hosted, what country it will be stored in?data is hosted, what country it will be stored in?

•Traditional SecurityTraditional Security

- These concerns involve computer and network intrusions or attacks - These concerns involve computer and network intrusions or attacks that will be made possible or at least easier by moving to the cloud. that will be made possible or at least easier by moving to the cloud.

Concerns in this category include:Concerns in this category include: Authentication and Authorization :Authentication and Authorization :

- The enterprise authentication and authorization framework - The enterprise authentication and authorization framework does not naturally extend into the cloud. How does a company meld does not naturally extend into the cloud. How does a company meld its existing framework to include cloud resources? Furthermore, how its existing framework to include cloud resources? Furthermore, how does an enterprise merge cloud security data (if even available) with does an enterprise merge cloud security data (if even available) with its own security metrics and policies? its own security metrics and policies?

VM-level attacks. VM-level attacks.

- Potential vulnerabilities in the VM technology used by cloud - Potential vulnerabilities in the VM technology used by cloud vendors are a potential problem in multi-tenant architectures. vendors are a potential problem in multi-tenant architectures.

•Third-party data control Third-party data control

Cloud computing facilitates storage of data at a remote site to Cloud computing facilitates storage of data at a remote site to maximize resource utilization. As a result, it is critical that this data maximize resource utilization. As a result, it is critical that this data be protected and only given to authorized individuals.be protected and only given to authorized individuals.

This essentially amounts to secure third party publication of data This essentially amounts to secure third party publication of data that is necessary for data outsourcing, as well as external that is necessary for data outsourcing, as well as external publications.publications.

The legal implications of data and applications being held by a third The legal implications of data and applications being held by a third party are complex and not well understood. There is also a potential party are complex and not well understood. There is also a potential lack of control and transparency when a third party holds the data.lack of control and transparency when a third party holds the data.

All this is prompting some companies to build private clouds to avoid All this is prompting some companies to build private clouds to avoid these issues and yet retain some of the advantages of cloud these issues and yet retain some of the advantages of cloud computing. computing.

Operational securityOperational security

Who has access? Who has access? - Access control is a key concern, because insider - Access control is a key concern, because insider

attacks are a huge risk. A potential hacker is someone who has attacks are a huge risk. A potential hacker is someone who has been entrusted with approved access to the cloud.been entrusted with approved access to the cloud.

- Anyone considering using the cloud needs to look at - Anyone considering using the cloud needs to look at who is managing their data and what types of controls are applied to who is managing their data and what types of controls are applied to these individuals.these individuals.

What type of training does the provider offer their customers ? What type of training does the provider offer their customers ?

- - This is actually a rather important item, because people This is actually a rather important item, because people will always be the weakest link in security. Knowing how your will always be the weakest link in security. Knowing how your provider trains their customers is an important item to review.provider trains their customers is an important item to review.

What is the long-term viability of the provider?What is the long-term viability of the provider?

- - How long has the cloud provider been in business and How long has the cloud provider been in business and what is their track record. If they go out of business, what happens what is their track record. If they go out of business, what happens to your data? Will your data be returned, and if so, in what format?to your data? Will your data be returned, and if so, in what format?

What is the disaster recovery/business continuity What is the disaster recovery/business continuity plan ?plan ?

- - While you may not know the physical location of your While you may not know the physical location of your services, it is physically located somewhere. All physical locations services, it is physically located somewhere. All physical locations face threats such as storms, natural disasters, and loss of power.face threats such as storms, natural disasters, and loss of power.

- In case of any of these events, how will the cloud - In case of any of these events, how will the cloud provider respond, and what guarantee of continued services are provider respond, and what guarantee of continued services are they promising?they promising?

Cloud Computing AttacksCloud Computing Attacks

As more companies move to cloud computing, look for hackers to As more companies move to cloud computing, look for hackers to follow. Some of the potential attack vectors criminals may attempt follow. Some of the potential attack vectors criminals may attempt include:include:

Denial of Service (DoS) attacksDenial of Service (DoS) attacks

- Some security professionals have argued that the cloud is - Some security professionals have argued that the cloud is more vulnerable to DoS attacks, because it is shared by many users, more vulnerable to DoS attacks, because it is shared by many users, which makes DoS attacks much more damaging.which makes DoS attacks much more damaging.

- Twitter suffered a devastating DoS attack during 2009.- Twitter suffered a devastating DoS attack during 2009.

Side Channel attacksSide Channel attacks

– – An attacker could attempt to compromise the cloud by placing a An attacker could attempt to compromise the cloud by placing a malicious virtual machine in close proximity to a target cloud server malicious virtual machine in close proximity to a target cloud server and then launching a side channel attack.and then launching a side channel attack.

Authentication attacksAuthentication attacks

– – Authentication is a weak point in hosted and virtual services and is Authentication is a weak point in hosted and virtual services and is frequently targeted. There are many different ways to authenticate users; frequently targeted. There are many different ways to authenticate users; for example, based on what a person knows, has, or is. for example, based on what a person knows, has, or is.

- The mechanisms used to secure the authentication process and - The mechanisms used to secure the authentication process and the methods used are a frequent target of attackers.the methods used are a frequent target of attackers.

Man-in-the-middle cryptographic attacksMan-in-the-middle cryptographic attacks

– – This attack is carried out when an attacker places himself between This attack is carried out when an attacker places himself between two users. Anytime attackers can place themselves in the communication’s two users. Anytime attackers can place themselves in the communication’s path, there is the possibility that they can intercept and modify path, there is the possibility that they can intercept and modify communications.communications.

AUTHENTICATIONAUTHENTICATION

In the cloud environment, authentication and access control are In the cloud environment, authentication and access control are more important than ever since the cloud and all of its data are more important than ever since the cloud and all of its data are accessible to anyone over the Internet. The accessible to anyone over the Internet. The TPM(see note)TPM(see note) can easily can easily provide stronger authentication than username and passwords.provide stronger authentication than username and passwords.

When a user is fired or reassigned, the customer’s identity When a user is fired or reassigned, the customer’s identity management system can notify the cloud provider in real-time so that management system can notify the cloud provider in real-time so that the user’s cloud access can be modified or revoked within second. the user’s cloud access can be modified or revoked within second.

If the fired user is logged into the cloud, they can be If the fired user is logged into the cloud, they can be immediately disconnected. Trusted Computing enables authentication of immediately disconnected. Trusted Computing enables authentication of client PCs and other devices, which also is critical to ensuring security client PCs and other devices, which also is critical to ensuring security in cloud computing.in cloud computing.

key guidelineskey guidelines :- :-

Carefully plan the security and privacy aspects of cloud Carefully plan the security and privacy aspects of cloud computing solutions before engaging themcomputing solutions before engaging them..

• Planning helps to ensure that the computing environment is as Planning helps to ensure that the computing environment is as secure as possible and is in compliance with all relevant secure as possible and is in compliance with all relevant Organizational policies and that data privacy is maintained.Organizational policies and that data privacy is maintained.

• To maximize effectiveness and minimize costs, security and privacy To maximize effectiveness and minimize costs, security and privacy must be considered from the initial planning stage at the start of the must be considered from the initial planning stage at the start of the systems development life cycle.systems development life cycle.

• Attempting to address security after implementation and Attempting to address security after implementation and deployment is not only much more difficult and expensive, but also deployment is not only much more difficult and expensive, but also more risky.more risky.

Understand the cloud computing environment offered by the Understand the cloud computing environment offered by the cloud provider and ensure that a cloud computing solution cloud provider and ensure that a cloud computing solution satisfies organizational security and privacy requirements.satisfies organizational security and privacy requirements.

• Cloud providers are generally not aware of a specific organization’s Cloud providers are generally not aware of a specific organization’s security and privacy needs.security and privacy needs.

• Organizations should require that any selected public cloud computing Organizations should require that any selected public cloud computing solution is configured, deployed, and managed to meet their security, solution is configured, deployed, and managed to meet their security, privacy, and other requirements.privacy, and other requirements.

• Critical data and applications may require an agency to undertake a Critical data and applications may require an agency to undertake a negotiated service agreement in order to use a public cloud.negotiated service agreement in order to use a public cloud.

• Other alternatives include cloud computing environments with a more Other alternatives include cloud computing environments with a more suitable deployment model, such as a private cloud, which offers an suitable deployment model, such as a private cloud, which offers an organization greater oversight and control over security and privacy.organization greater oversight and control over security and privacy.

Ensure that the client-side computing environment meets Ensure that the client-side computing environment meets organizational security and privacy requirements for cloud organizational security and privacy requirements for cloud computing.computing.

• Cloud computing encompasses both a server and a client sideCloud computing encompasses both a server and a client side..• Maintaining physical and logical security over clients can be Maintaining physical and logical security over clients can be

troublesome, especially with embedded mobile devices such as smart troublesome, especially with embedded mobile devices such as smart phones.phones.

• Built-in security mechanisms often go unused or can be overcome or Built-in security mechanisms often go unused or can be overcome or circumvented without difficulty by a knowledgeable party to gain control circumvented without difficulty by a knowledgeable party to gain control over the device.over the device.

• Because of their ubiquity, Web browsers are a key element for client-Because of their ubiquity, Web browsers are a key element for client-side access to cloud computing services. Clients may also entail small side access to cloud computing services. Clients may also entail small lightweight applications that run on desktop and mobile devices to lightweight applications that run on desktop and mobile devices to

access services.access services. • The various available plug-ins and extensions for Web browsers are The various available plug-ins and extensions for Web browsers are

notorious for their security problems. Many browser add-ons also do not notorious for their security problems. Many browser add-ons also do not provide automatic updates, increasing the persistence of any existing provide automatic updates, increasing the persistence of any existing vulnerabilities.vulnerabilities.

Maintain accountability over the privacy and security of Maintain accountability over the privacy and security of data and applications implemented and deployed in public data and applications implemented and deployed in public cloud computing environmentscloud computing environments

• Organizations should employ appropriate security management practices Organizations should employ appropriate security management practices and controls over cloud computing. Strong management practices are and controls over cloud computing. Strong management practices are essential for operating and maintaining a secure cloud computing solution. essential for operating and maintaining a secure cloud computing solution.

• Establishing a level of confidence about a cloud service environment Establishing a level of confidence about a cloud service environment depends on the ability of the cloud provider to provision the security depends on the ability of the cloud provider to provision the security controls necessary to protect the organization’s data and applications.controls necessary to protect the organization’s data and applications.

Server-Side Protection.Server-Side Protection.

Virtual servers and applications, need to be secured both physically Virtual servers and applications, need to be secured both physically and logically.and logically.

organizational policies and procedures, hardening of the operating organizational policies and procedures, hardening of the operating system and applications should occur to produce virtual machine system and applications should occur to produce virtual machine images for deployment.images for deployment.

Care must also be taken to provision security for the virtualized Care must also be taken to provision security for the virtualized environments in which the images run.environments in which the images run.

virtual firewalls can be used to isolate groups of virtual machines from virtual firewalls can be used to isolate groups of virtual machines from other hosted groups, such as production systems from development other hosted groups, such as production systems from development systems or development systems from other cloud-resident systemssystems or development systems from other cloud-resident systems

Carefully managing virtual machine images is also important to avoid Carefully managing virtual machine images is also important to avoid accidentally deploying images under development or containing accidentally deploying images under development or containing vulnerabilities.vulnerabilities.

Some issues and the precautions that apply as a set of Some issues and the precautions that apply as a set of recommendations for organizations to follow when planning, recommendations for organizations to follow when planning, reviewing, negotiating, or initiating a public cloud service reviewing, negotiating, or initiating a public cloud service outsourcing arrangement.outsourcing arrangement.

• GovernanceGovernance : :

Extend organizational practices pertaining to the policies, Extend organizational practices pertaining to the policies, procedures, and standards used for application development and service procedures, and standards used for application development and service provisioning in the cloud, as well as the design, implementation, testing, provisioning in the cloud, as well as the design, implementation, testing, and monitoring of deployed or engaged services.and monitoring of deployed or engaged services.

Put in place audit mechanisms and tools to ensure Put in place audit mechanisms and tools to ensure organizational practices are followed throughout the system lifecycle.organizational practices are followed throughout the system lifecycle.

• ComplianceCompliance : :

Understand the various types of laws and regulations that impose Understand the various types of laws and regulations that impose security and privacy obligations on the organization.security and privacy obligations on the organization.

Review and assess the cloud provider’s offerings with respect to Review and assess the cloud provider’s offerings with respect to the organizational requirements to be met and ensure that the contract the organizational requirements to be met and ensure that the contract terms adequately meet the requirements.terms adequately meet the requirements.

Data ProtectionData Protection : :

Evaluate the suitability of the cloud provider’s data Evaluate the suitability of the cloud provider’s data management solutions for the organizational data concerned.management solutions for the organizational data concerned.

AvailabilityAvailability : :

Ensure that during an intermediate or prolonged disruption Ensure that during an intermediate or prolonged disruption or a serious disaster, critical operations can be immediately resumed or a serious disaster, critical operations can be immediately resumed and that all operations can be eventually reinstituted in a timely and and that all operations can be eventually reinstituted in a timely and organized manner.organized manner.

TrustTrust : :

Incorporate mechanisms into the contract that allow visibility Incorporate mechanisms into the contract that allow visibility into the security and privacy controls and processes employed by the into the security and privacy controls and processes employed by the cloud provider, and their performance over time.cloud provider, and their performance over time.

Institute a risk management program that is flexible enough Institute a risk management program that is flexible enough to adapt to the continuously evolving and shifting risk landscape.to adapt to the continuously evolving and shifting risk landscape.

Identity and AccessIdentity and Access

Management Ensure that adequate safeguards are in place Management Ensure that adequate safeguards are in place to secure authentication, authorization, and other identity and access to secure authentication, authorization, and other identity and access management functions.management functions.

DATA ISSUESDATA ISSUES

Data LossData Loss :- :- Data loss is a very serious problem in Cloud computing. If Data loss is a very serious problem in Cloud computing. If

the vendor closes due to financial or legal problems there will be a the vendor closes due to financial or legal problems there will be a loss of data for the customers. The customers won’t be able to loss of data for the customers. The customers won’t be able to access those data’s because data is no more available for the access those data’s because data is no more available for the customer as the vendor shut down.customer as the vendor shut down.

Data LocationData Location :- :- When it comes to location of the data nothing is When it comes to location of the data nothing is

transparent even the customer don’t know where his own data’s are transparent even the customer don’t know where his own data’s are located. The Vendor does not reveal where all the data’s are stored. located. The Vendor does not reveal where all the data’s are stored. The Data’s won’t even be in the same country of the Customer, it The Data’s won’t even be in the same country of the Customer, it might be located anywhere in the world.might be located anywhere in the world.

• Data Lock-In :-Data Lock-In :-

Software stacks have improved interoperability among Software stacks have improved interoperability among platforms, but the APIs for Cloud Computing itself are still platforms, but the APIs for Cloud Computing itself are still essentially proprietary, or at least have not been the subject of essentially proprietary, or at least have not been the subject of active standardization. active standardization.

Thus, customers cannot easily extract their data and Thus, customers cannot easily extract their data and programs from one site to run on another.programs from one site to run on another.

For example, an online storage service called The Linkup For example, an online storage service called The Linkup shut down on August 8, 2008 after losing access as much as 45% shut down on August 8, 2008 after losing access as much as 45% of customer data [12]. The Linkup, in turn, had relied on the online of customer data [12]. The Linkup, in turn, had relied on the online storage service Nirvanix to store customer data, and now there is storage service Nirvanix to store customer data, and now there is finger pointing between the two organizations as to why customer finger pointing between the two organizations as to why customer data was lost.data was lost.

The obvious solution is to standardize the APIs so that a The obvious solution is to standardize the APIs so that a SaaS developer could deploy services and data across multiple SaaS developer could deploy services and data across multiple Cloud Computing providers so that the failure of a single company Cloud Computing providers so that the failure of a single company would not take all copies of customer data with it.would not take all copies of customer data with it.

• Data segregationData segregation :- :-    Data in the cloud is typically stored in a shared environment whereby one Data in the cloud is typically stored in a shared environment whereby one

customer’s data is stored alongside another customer’s data. hence it is difficult to customer’s data is stored alongside another customer’s data. hence it is difficult to assure data segregation.assure data segregation.

   customers should review the cloud vendor’s architecture to ensure proper data customers should review the cloud vendor’s architecture to ensure proper data segregation is available and that data leak prevention (DLP) measures are in place.segregation is available and that data leak prevention (DLP) measures are in place.

Nearly all service providers now support SSL(secure socket layer-protocol) Nearly all service providers now support SSL(secure socket layer-protocol) connections to ensure that the provider is encrypting the data traversing the network.connections to ensure that the provider is encrypting the data traversing the network.

When the service provider provides encryption for the consumer’s data, When the service provider provides encryption for the consumer’s data, the consumer should be concerned with the protocols and implementation of the the consumer should be concerned with the protocols and implementation of the encryption system, as these two factors dictate the effectiveness of the encryption encryption system, as these two factors dictate the effectiveness of the encryption system.system.

• Data Confidentiality and AuditabilityData Confidentiality and Auditability :- :-

Current cloud offerings are essentially public Current cloud offerings are essentially public

(rather than private) networks, exposing the system to more attacks.(rather than private) networks, exposing the system to more attacks.

Auditability could be added as an additional layer beyond Auditability could be added as an additional layer beyond the reach of the virtualized guest OS (or virtualized application the reach of the virtualized guest OS (or virtualized application environment), providing facilities arguably more secure than those environment), providing facilities arguably more secure than those built into the applications themselves and centralizing the software built into the applications themselves and centralizing the software responsibilities related to confidentiality and auditability into a single responsibilities related to confidentiality and auditability into a single logical layer.logical layer.

• Data integrity and data theftData integrity and data theft :- :-

(as we have shown it as a part of security issues)(as we have shown it as a part of security issues)

• Deletion of dataDeletion of data :- :- An essential point is that data that has to be deleted by An essential point is that data that has to be deleted by

the user because he or she no longer needs it or may no longer the user because he or she no longer needs it or may no longer process it for another reason is also deleted by the provider and no process it for another reason is also deleted by the provider and no more copies of data are available. more copies of data are available. 

This can lead to problems, in particular in connection This can lead to problems, in particular in connection with backups that are created by the provider if these contain data with backups that are created by the provider if these contain data belonging to a number of his customers and targeted deletion of belonging to a number of his customers and targeted deletion of individual data items proves financially unreasonable or technically individual data items proves financially unreasonable or technically inappropriate in terms of feasibility.inappropriate in terms of feasibility.

Data deletion is also of prime importance when Data deletion is also of prime importance when terminating the contract with the provider.terminating the contract with the provider.

• Restitution of dataRestitution of data :- :-

Upon termination of the contract, the orderly return Upon termination of the contract, the orderly return of data to the user has to be ensured. This requires sufficiently long of data to the user has to be ensured. This requires sufficiently long periods of notice for the user to be able to take the necessary periods of notice for the user to be able to take the necessary measures to ensure the availability and constant further processing measures to ensure the availability and constant further processing of data after termination of the contract. The form in which the data of data after termination of the contract. The form in which the data is to be delivered to the user by the provider must also be is to be delivered to the user by the provider must also be ascertained.ascertained.

• Service level agreementsService level agreements :- :- According to the purpose for which the data is According to the purpose for which the data is processed it is important to agree on binding service levels for processed it is important to agree on binding service levels for availability and data recovery and if necessary, safeguarded by availability and data recovery and if necessary, safeguarded by supporting fixed penalties in the event of non-compliance with the supporting fixed penalties in the event of non-compliance with the agreed service levels.agreed service levels.

Topics covered till now…Topics covered till now…

IntroductionIntroduction

Types of services and architectureTypes of services and architecture

Security issuesSecurity issues

Data related issuesData related issues

Topics will be covered…Topics will be covered…

Performance issuesPerformance issues

Bandwidth related issuesBandwidth related issues

Cloud interoperabilityCloud interoperability

Energy related issuesEnergy related issues

Fault toleranceFault tolerance

Conclusion Conclusion

PERFOMANCE ISSUESPERFOMANCE ISSUES WHY PERFOMANCE ?WHY PERFOMANCE ?

• Poor application performance causes companies to lose Poor application performance causes companies to lose customers,customers,

reduce employee productivity, and reduce bottom line revenue.reduce employee productivity, and reduce bottom line revenue.

• Application crashes due to poor performance cost money and Application crashes due to poor performance cost money and impact morale. If applications cannot adequately perform during an impact morale. If applications cannot adequately perform during an increase in traffic, businesses lose customers and revenueincrease in traffic, businesses lose customers and revenue

• Sluggish access to data, applications, and Web pages frustratesSluggish access to data, applications, and Web pages frustrates

employees and customers alike, and some performance problems employees and customers alike, and some performance problems and bottlenecks can even cause application crashes and data and bottlenecks can even cause application crashes and data losses. losses.

• Positive employee productivity relies on solid and reliable Positive employee productivity relies on solid and reliable application performance to complete work accurately and quickly.application performance to complete work accurately and quickly.

In general the issues may be…In general the issues may be…

• Poor application performance or application hang-ups : Poor application performance or application hang-ups :

Usually the application is starved for RAM or CPU cycles, and Usually the application is starved for RAM or CPU cycles, and faster processors or more RAM is added.faster processors or more RAM is added.

• Slow access to applications and data :Slow access to applications and data :

Bandwidth is usually the cause, and the most common solution is to Bandwidth is usually the cause, and the most common solution is to add faster network connections.add faster network connections.

• When companies or cloud vendors take the simplistic “more hardware When companies or cloud vendors take the simplistic “more hardware solves the problem” approach to cloud performance, they waste money.solves the problem” approach to cloud performance, they waste money.

• Hence, Adding virtual machines may be a short-term solution to the Hence, Adding virtual machines may be a short-term solution to the problem, but adding machines is a manual task. If a company experiences a problem, but adding machines is a manual task. If a company experiences a sudden spike in traffic, how quickly will the vendor notice the spike and sudden spike in traffic, how quickly will the vendor notice the spike and assign a technician to provision more resources to the account?assign a technician to provision more resources to the account?

• Storage, CPU, memory, and network bandwidth all come into play at Storage, CPU, memory, and network bandwidth all come into play at various times during typical application use.various times during typical application use.

• For example, Application switching places demands on the CPU as one For example, Application switching places demands on the CPU as one application is closed, flushed from the registers, and another application application is closed, flushed from the registers, and another application is loaded. If these applications are large and complex, they put a greater is loaded. If these applications are large and complex, they put a greater demand on the CPU.demand on the CPU.

• Serving files from the cloud to connected users stresses a number ofServing files from the cloud to connected users stresses a number of

resources, including disk drives, drive controllers, and networkresources, including disk drives, drive controllers, and network

connections when transferring the data from the cloud to the user.connections when transferring the data from the cloud to the user.

• Therefore, one of the most common and costly responses to scaling Therefore, one of the most common and costly responses to scaling issues by vendors is to over-provision customer installations to issues by vendors is to over-provision customer installations to accommodate a wide range of performance issues.accommodate a wide range of performance issues.

• To system performance through hardware and software throughput To system performance through hardware and software throughput gains is defeated when a system is swamped by multiple, simultaneous gains is defeated when a system is swamped by multiple, simultaneous demands. demands.

• That 10 gigabit pipe slows considerably when it serves hundreds of That 10 gigabit pipe slows considerably when it serves hundreds of requests rather than a dozen. The only way to restore higher effective requests rather than a dozen. The only way to restore higher effective throughput and performance in such a “swamped resources” scenario throughput and performance in such a “swamped resources” scenario is to scale – add more of the resource that is overloaded.is to scale – add more of the resource that is overloaded.

Horizontal and Vertical Scalability :Horizontal and Vertical Scalability :

When increasing resources on the cloud to restore or improveWhen increasing resources on the cloud to restore or improve

application performance, administrators can scale either horizontallyapplication performance, administrators can scale either horizontally

(out) or vertically (up), depending on the nature of the resource(out) or vertically (up), depending on the nature of the resource

constraint.constraint.

VERTICAL SCALING :VERTICAL SCALING :

Vertical scaling (up) entails adding more resources to theVertical scaling (up) entails adding more resources to the

same computing pool. -- for example, adding more RAM, disk, to handle an same computing pool. -- for example, adding more RAM, disk, to handle an increased application load.increased application load.

Vertical scaling can handle most sudden, temporaryVertical scaling can handle most sudden, temporary

peaks in application demand on cloud infrastructures since they are notpeaks in application demand on cloud infrastructures since they are not

typically CPU intensive tasks.typically CPU intensive tasks.

HORIZONTAL SCALING :HORIZONTAL SCALING :

Horizontal scaling (out) requires the addition of more machinesHorizontal scaling (out) requires the addition of more machines

devices to the computing platform to handle the increased demanddevices to the computing platform to handle the increased demand

Sustained increases in demand, however, require horizontalSustained increases in demand, however, require horizontal

scaling and load balancing to restore and maintain peak performance.scaling and load balancing to restore and maintain peak performance.

Administrative and Geographical ScalabilityAdministrative and Geographical Scalability

• While adding computing components or virtual resources is a logicalWhile adding computing components or virtual resources is a logical

means to scale and improve performance, few companies realize thatmeans to scale and improve performance, few companies realize that

the increase in resources may also necessitate an increase inthe increase in resources may also necessitate an increase in

administrationadministration

• Hence, Companies with critical cloud applications may also considerHence, Companies with critical cloud applications may also consider

geographical scaling as a means to more widely distribute applicationgeographical scaling as a means to more widely distribute application

load demands or as a way to move application access closer toload demands or as a way to move application access closer to

dispersed communities of users or customers.dispersed communities of users or customers.

• Geographical scaling may also be necessary in environments where Geographical scaling may also be necessary in environments where it is impractical to host all data or applications in one central location.it is impractical to host all data or applications in one central location.

Bandwidth requirementBandwidth requirement

Security concerns have long dominated much of the cloud Security concerns have long dominated much of the cloud conversation and caused many companies to deliberate about conversation and caused many companies to deliberate about getting started in the cloudgetting started in the cloud

But while the focus has been on cloud security, another potential But while the focus has been on cloud security, another potential bottlenecks are on the way like – bandwidth requirement.bottlenecks are on the way like – bandwidth requirement.

Since bandwidth is rarely a problem for companies exploring the Since bandwidth is rarely a problem for companies exploring the cloud in a small way,  But as they start expanding their cloud cloud in a small way,  But as they start expanding their cloud footprint and running production-oriented applications, data footprint and running production-oriented applications, data movement takes on a completely different scale. movement takes on a completely different scale.

As enterprises start to move real workloads out to the cloud look for As enterprises start to move real workloads out to the cloud look for bandwidth to become top of mind.bandwidth to become top of mind.

The problem arise when…The problem arise when…

when you have dozens of developers all trying to use cloud when you have dozens of developers all trying to use cloud resources? resources?

When you put high-transaction processes in the cloud that need to When you put high-transaction processes in the cloud that need to “talk back” to your data center?  “talk back” to your data center? 

When you are trying to move a lot of video or graphics between your When you are trying to move a lot of video or graphics between your business users and the cloud? business users and the cloud? 

Hence , Network usage is about to get much more Hence , Network usage is about to get much more

demanding, and the traffic will need to flow without bottlenecks (or demanding, and the traffic will need to flow without bottlenecks (or

saturating the network) for an organization’s cloud strategy to work.saturating the network) for an organization’s cloud strategy to work.

The scenario in most cloud is, at low load, App Engine will not The scenario in most cloud is, at low load, App Engine will not dedicate much server resource to an application, letting a single dedicate much server resource to an application, letting a single server monitor the application. server monitor the application.

When this server is subjected to an extremely heavy load, the single When this server is subjected to an extremely heavy load, the single App Engine server appears to make connection and service every App Engine server appears to make connection and service every request that arrives to an application at least partially, regardless of request that arrives to an application at least partially, regardless of the number and size. the number and size.

In the meantime, it appears to be calling for assistance from the In the meantime, it appears to be calling for assistance from the other servers in the cluster in order to distribute the load efficiently. other servers in the cluster in order to distribute the load efficiently.

This would probably result in a delay in servicing a request for the This would probably result in a delay in servicing a request for the client.client.

According to the Network Performance Frustration Research Report According to the Network Performance Frustration Research Report by Dimension Data ,The Internet traffic that includes cloud services by Dimension Data ,The Internet traffic that includes cloud services of 2015 will be at least 50 times larger than it was in 2006.of 2015 will be at least 50 times larger than it was in 2006.

Thus the network growth at these levels will require a dramatic Thus the network growth at these levels will require a dramatic expansion of bandwidth, storage, and traffic management expansion of bandwidth, storage, and traffic management

The proposed solutions are…The proposed solutions are…

With the increase of cloud traffic, some cloud service providers With the increase of cloud traffic, some cloud service providers direct their client’s traffic to the geographically closest available direct their client’s traffic to the geographically closest available servers.servers.

Use of High Speed Edge Routers : -Use of High Speed Edge Routers : -

Another requirement for traffic problem elimination is Another requirement for traffic problem elimination is installing high-performance, intelligent routers at the edge of the installing high-performance, intelligent routers at the edge of the network, through which operators can efficiently manage bandwidth network, through which operators can efficiently manage bandwidth while delivering cloud services over cable infrastructure.while delivering cloud services over cable infrastructure.

Edge routers focus on processing large numbers of cloud packetsEdge routers focus on processing large numbers of cloud packets

with simplified per packet logic. with simplified per packet logic.

To be effective edge routers also need to offer support advanced-To be effective edge routers also need to offer support advanced-load balancing to guarantee the optimization of network load balancing to guarantee the optimization of network infrastructure assets.infrastructure assets.

There is also a proposed solution to use optical fiber to connect all There is also a proposed solution to use optical fiber to connect all the nodes to improve bandwidth. But the problem is increase in the nodes to improve bandwidth. But the problem is increase in cost.cost.

Other problem is that this will not be going to happen globally in Other problem is that this will not be going to happen globally in near future since replacement of these technologies will cost high near future since replacement of these technologies will cost high and cannot be employed globally in one day.and cannot be employed globally in one day.

So , some cloud vendors applied this technology only for connecting So , some cloud vendors applied this technology only for connecting cloud servers and has improve up to some extent cloud servers and has improve up to some extent

Cloud interoperabilityCloud interoperability

There may be situations where an organization or enterprise needs There may be situations where an organization or enterprise needs to be able to work with multiple cloud providers.to be able to work with multiple cloud providers.

Cloud interoperability and the ability to share various types of Cloud interoperability and the ability to share various types of information between clouds become important in such scenarios.information between clouds become important in such scenarios.

This broad area of cloud interoperability is sometimes known This broad area of cloud interoperability is sometimes known as cloud federation.as cloud federation.

"Cloud federation manages consistency and access "Cloud federation manages consistency and access controls when two or more independent geographically controls when two or more independent geographically distributed clouds share either authentication, files, distributed clouds share either authentication, files, computing resources, command and control, or access computing resources, command and control, or access to storage resources."to storage resources."

The following are some of the considerations in cloud federation:The following are some of the considerations in cloud federation:

1. An enterprise user wishing to access multiple cloud services 1. An enterprise user wishing to access multiple cloud services would be better served if there were just a single sign-on scheme. would be better served if there were just a single sign-on scheme. This scheme may be implemented through a central trusted This scheme may be implemented through a central trusted authentication server to which all the cloud services interface could authentication server to which all the cloud services interface could be used.be used.

2. An often-ignored concern for cloud confederation is charging or 2. An often-ignored concern for cloud confederation is charging or billing and reconciliation. Management and billing systems need to billing and reconciliation. Management and billing systems need to work together for cloud federation to be a viable option. This reality work together for cloud federation to be a viable option. This reality is underlined by the fact that clouds rely on per-use billing.is underlined by the fact that clouds rely on per-use billing.

Cloud federation is a relatively new area in cloud computing. It is Cloud federation is a relatively new area in cloud computing. It is likely that standards bodies will first need to agree upon a set of likely that standards bodies will first need to agree upon a set of requirements before the service interfaces can be defined and requirements before the service interfaces can be defined and subsequently realized. subsequently realized. 

ENERGY RELATED ISSUESENERGY RELATED ISSUES

Cloud computing is rapidly growing in importance as increasing Cloud computing is rapidly growing in importance as increasing numbers of enterprises and individuals are shifting their workloads numbers of enterprises and individuals are shifting their workloads to cloud service providers. Services offered by cloud providers such to cloud service providers. Services offered by cloud providers such as Amazon, Microsoft, IBM, and Google are implemented on as Amazon, Microsoft, IBM, and Google are implemented on thousands of servers spread across multiple geographically thousands of servers spread across multiple geographically distributed data centers.distributed data centers.

The electricity costs involved in operating a large cloud The electricity costs involved in operating a large cloud infrastructure of multiple data centers can be enormous. In fact, infrastructure of multiple data centers can be enormous. In fact, cloud service providers often must pay for the peak power they cloud service providers often must pay for the peak power they draw, as well as the energy they consume.draw, as well as the energy they consume.

Lowering these high operating costs is one of the challenges facing Lowering these high operating costs is one of the challenges facing cloud service providers.cloud service providers.

Moreover, there are other crucial problems that arise from high Moreover, there are other crucial problems that arise from high power consumption. Insufficient or malfunctioning cooling system power consumption. Insufficient or malfunctioning cooling system can lead to overheating of the resources reducing system reliability can lead to overheating of the resources reducing system reliability and devices lifetime.and devices lifetime.

In addition, high power consumption by the infrastructure leads to In addition, high power consumption by the infrastructure leads to substantial carbon dioxide (Cosubstantial carbon dioxide (Co22) emissions contributing) emissions contributing to the to the

greenhouse effect.greenhouse effect.

Solutions :- Solutions :-

Geographical distribution of the data centers exposes many Geographical distribution of the data centers exposes many opportunities for cost savings due to more energy consumption.opportunities for cost savings due to more energy consumption.

First, the data centers are often exposed to different electricity First, the data centers are often exposed to different electricity markets, meaning that they pay different energy and peak power markets, meaning that they pay different energy and peak power prices. prices.

Finally, the data centers may be located in areas with widely Finally, the data centers may be located in areas with widely different outside temperatures, which have an impact on the amount different outside temperatures, which have an impact on the amount of cooling energy used.of cooling energy used.

Solutions :- Solutions :-

Geographical distribution of the data centers exposes many Geographical distribution of the data centers exposes many opportunities for cost savings due to more energy consumption.opportunities for cost savings due to more energy consumption.

the data centers are often exposed to different electricity markets, the data centers are often exposed to different electricity markets, meaning that they pay different energy and peak power prices. meaning that they pay different energy and peak power prices.

Finally, the data centers may be located in areas with widely Finally, the data centers may be located in areas with widely different outside temperatures, which have an impact on the amount different outside temperatures, which have an impact on the amount of cooling energy used.of cooling energy used.

Given the different characteristics of the data centers’ energy Given the different characteristics of the data centers’ energy consumptions, energy prices, and peak power prices, it becomes consumptions, energy prices, and peak power prices, it becomes clear that we can lower operating costs by intelligently placing clear that we can lower operating costs by intelligently placing (distributing) the computational load across the wide area.(distributing) the computational load across the wide area.

Load distribution policy for distributing client load across multiple Load distribution policy for distributing client load across multiple data centers to minimize electricity cost.data centers to minimize electricity cost.

To reduce energy consumption and cost, each data center only To reduce energy consumption and cost, each data center only keeps as many servers active as necessary to service the current keeps as many servers active as necessary to service the current workload.workload.

FAULT TOLERANCEFAULT TOLERANCE

Fault Tolerance is one of the key issues of cloud computing. Fault Fault Tolerance is one of the key issues of cloud computing. Fault tolerance is concerned with all the techniques necessary to enable a tolerance is concerned with all the techniques necessary to enable a system to tolerate software faults. system to tolerate software faults.

These software faults may or may not manifest themselves during These software faults may or may not manifest themselves during systems operations, but when they do, software fault tolerant systems operations, but when they do, software fault tolerant techniques should provide the necessary mechanisms of the techniques should provide the necessary mechanisms of the software system to prevent system failure occurrences. software system to prevent system failure occurrences.

Fault tolerance techniques are employed during the procurement, or Fault tolerance techniques are employed during the procurement, or development, of the software. When a fault occurs, these development, of the software. When a fault occurs, these techniques provide mechanisms to the software system to prevent techniques provide mechanisms to the software system to prevent system failure from occurring system failure from occurring

FAULT TOLERANCE POLICIES :FAULT TOLERANCE POLICIES :

Fault tolerance (FT) policies can typically be listed into two sets: Fault tolerance (FT) policies can typically be listed into two sets: reactive fault tolerance policies and proactive fault tolerance reactive fault tolerance policies and proactive fault tolerance policies. policies.

While reactive fault tolerance policies reduces the effect of failures While reactive fault tolerance policies reduces the effect of failures on application execution when the failure effectively occurs; on application execution when the failure effectively occurs; proactive fault tolerance policies keeps applications alive by proactive fault tolerance policies keeps applications alive by avoiding failures through preventative measures. avoiding failures through preventative measures.

The principle of proactive action is to avoid clouds from faults, errors The principle of proactive action is to avoid clouds from faults, errors and failures by predicting them and proactively replace the and failures by predicting them and proactively replace the suspected components by other correctly working components suspected components by other correctly working components providing the same function. providing the same function.

There are some approach like. . . There are some approach like. . .

- Micro reboot techniques- Micro reboot techniques

- Filtering malicious input - Filtering malicious input

Another approach is HA PROXY.Another approach is HA PROXY.

HA Proxy stands for High Availability Proxy and is used by HA Proxy stands for High Availability Proxy and is used by companies for load balancing and server fail over in the cloud. companies for load balancing and server fail over in the cloud. Companies do not want their website to go down, or worse, for Companies do not want their website to go down, or worse, for users to notice the site is down. users to notice the site is down.

In HA Proxy there is typically a load balancer to distribute the load In HA Proxy there is typically a load balancer to distribute the load among a pool of web servers. among a pool of web servers.

Whenever a server goes down it is taken out of the pool until it is Whenever a server goes down it is taken out of the pool until it is once again ready to handle requests. once again ready to handle requests.

HA Proxy has the ability to perform this task by doing periodic health HA Proxy has the ability to perform this task by doing periodic health checks on all the servers in a cluster. Even if one of the application checks on all the servers in a cluster. Even if one of the application servers is not working, users will still have the availability to the servers is not working, users will still have the availability to the application.application.

HA Proxy will properly handle the request from users by redirecting HA Proxy will properly handle the request from users by redirecting them to the second server, giving the impression that all is well.them to the second server, giving the impression that all is well.

It monitors all the flow on the network and also health of different It monitors all the flow on the network and also health of different servers whenever any server fails it will redirect user request to servers whenever any server fails it will redirect user request to another server and inform administrator about that faults. another server and inform administrator about that faults.

Conclusion :Conclusion :

cloud computing is technology which enables the user to access cloud computing is technology which enables the user to access resources using front end machines , there is no need to install any resources using front end machines , there is no need to install any software.software.

It helps in convert CapEx into Opex . But every technology has pros It helps in convert CapEx into Opex . But every technology has pros and cons cloud computing has also various issues associated with and cons cloud computing has also various issues associated with it. . cloud computing provides many services like PaaS,IaaS,SaaS.it. . cloud computing provides many services like PaaS,IaaS,SaaS.

There are many issues and solutions are highlighted in this topic like There are many issues and solutions are highlighted in this topic like security issues, privacy issues, data related issues, energy related security issues, privacy issues, data related issues, energy related issues etc. We are using one of them services like Google docs, issues etc. We are using one of them services like Google docs, Gmail but we do not find such issues related with it.Gmail but we do not find such issues related with it.

Hence I conclude that this issues comes consider whenever we Hence I conclude that this issues comes consider whenever we consider it with big level companies , they are not going to affect consider it with big level companies , they are not going to affect much more as single user.much more as single user.

Some of the issues like bandwidth problems will not be longer due Some of the issues like bandwidth problems will not be longer due to technology are increasing and speed will not affect longer. So to technology are increasing and speed will not affect longer. So there are good scope in this field.there are good scope in this field.

THANK YOU…!THANK YOU…!