Friday, September 2, 2011

What is Cloud Computing...

Cloud Computing is a new concept which was recently came popular in computer industry. The main idea of cloud computing is the sharing of computing recourses among a community of users. The concept of cloud computing immerged in 1960s, when Johon McCarthy opined that "computation may someday be organized as a public utility”. The Condor project that started in 1988 at the University of Wisconsin-Madison was the successful implementation of Cloud computing concept. This project was motivated by the observation that a high percentage of the capacity of user’s workstations is idle while their users are away of their offices or doing other tasks such as reading or talking on the phone. These idle cycles can be harvested by the Condor system and made available to users who need more computing power than that available to them at their local workstations. In present Cloud computing developed as a web-based computing technology that offers a degree of freedom in the establishment of IT infrastructure. 
This paper discusses the concepts of cloud computing starting from the definition. Then it discusses advantages, disadvantages and the challenges of the cloud computing.

What is Cloud Computing- Definition
The term “cloud” is a metaphor to “Internet”. The Cloud computing defined as a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, server storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.
Cloud computing customers do not own the physical infrastructure rather they rent the usage from third party provider. They consume resources as a service and pay only for resources that they use. Most cloud computing infrastructures consist of services delivered through common centers and build on severs. Sharing resources amongst can improve the speed of computing when the servers are unnecessarily left idle.
Present Many companies like Google, Microsoft and are delivering services from the cloud. Google has a private cloud which gives their services like email services, document applications, text translations and maps. Microsoft Sharepoint online service allows for application tools to be moved into the cloud, and Microsoft currently makes its office applications available in a cloud.

Service Models of Cloud computing
Cloud computing offers both the software and hardware as a service over the internet. These services are classified into three categories:

1. Software as a Service (SaaS)
2. Platform as a Service (PaaS)
3. Infrastructure as a Service (IaaS)

1. Software as a Service (SaaS)
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 cloud & multiple end users are serviced. On the customers‟ side, there is no  need for  upfront investment in servers  or software licenses, while for the provider, the costs are lowered, since only  a single  application needs to be  hosted &  maintained. Today SaaS is  offered by companies such as Google, Salesforce, Microsoft, Zoho, etc.

2. Platform as a Service (PaaS)
Here, a layer of software, or development environment is  encapsulated & offered as a service, upon which other higher levels of service can be built. The customer has the freedom to build his own applications, which run on the provider‟s  infrastructure.  To meet manageability and scalability requirements of the applications, PaaS providers offer a predefined combination of OS and application servers, such as LAMP platform (Linux, Apache, MySql and PHP), restricted J2EE, Ruby etc. Google‟s App Engine,, etc are some of the popular PaaS examples.

3. Infrastructure as a Service (IaaS)
 IaaS provides  basic storage and computing capabilities as standardized services over the network. Servers, storage systems,  networking equipment,  data centre space etc.  are pooled and made available to handle workloads.  The  customer would typically deploy his own  software on the infrastructure. Some common examples are Amazon, GoGrid, 3 Tera, etc.

Cloud deployment models
Cloud computing model can be deployed in several ways. According to the characteristic of those models we can identified four main models.

1. Private Cloud 
The cloud infrastructure has been deployed, and is maintained and operated for a specific organization. The operation may be in-house or with a third party on the premises.

2. Community Cloud
 The cloud infrastructure is shared among a number of organizations with similar interests and requirements.
This may help limit the capital expenditure costs for its establishment as the costs are shared among the organizations. The operation may be in-house or with a third party on the premises.

3. Public Cloud 
 The cloud infrastructure is available to the public on a commercial basis by a cloud service provider. This enables a consumer to develop and deploy a service in the cloud with very little financial outlay compared to the capital.

4. Hybrid Cloud 
 The cloud infrastructure consists of a number of clouds of any type, but the clouds have the ability through their interfaces to allow data and/or applications to be moved from one cloud to another. This can be a combination of private and public clouds that support the requirement to retain some data in an organization, and also the need to offer services in the cloud.

The following are some of the possible benefits for those who offer cloud computing-based services and applications:

•  Cost Savings 
Initial expense is really cost effective. The billing model has a per usage basis. The Maintaining cost and service cost are much lower than the traditional computing methods.

•  Scalability/Flexibility
Cloud computing infrastructures have massive storage capacity. There for users can do computation with large size of data. If we consider in industrial level,
Companies can start with a small deployment and grow to a large deployment fairly rapidly, and then scale back if necessary. Also, the flexibility of cloud computing allows companies to use extra resources at peak times, enabling them to satisfy consumer demands.

•  Reliability
We can use multiple redundant clouds to do our computation purposes. This supports business continuity and disaster recovery.

• Maintenance
Cloud service providers do the system maintenance, and access is through APIs that do not require application installations onto PCs, thus further reducing maintenance requirements.

•  Mobile Accessible
This is also a major benefit coming with the cloud computing. Mobile workers have increased productivity due to systems accessible in an infrastructure available from anywhere.


• Data Security
Security is the main problem involves with the cloud computing structure. Cloud service providers can monitor the usage of the cloud and the data. Users don’t have the understanding about the  back end data storages. They don’t know exactly where they are storing their data. This problem can solve if service providers can assure a good security level and if they use any encrypting mechanism.

• Data Recovery and Availability
This is also a challenge which achieve by the service providers. The service providers should maintain a good disaster recovery system and  capacity and performance management system.

• Management Capabilities 
Despite there being multiple cloud providers, the management of platform and infrastructure is still in its infancy. Features like „Auto-scaling‟ for example, are a crucial requirement for many enterprises. There is huge potential to improve on the scalability and load balancing features provided today.

• Regulatory and Constitutional Restrictions 
In some of countries, Government regulations do not allow personal information and other sensitive information to be physically located outside the state or country. In order to meet such requirements, cloud providers need to setup a data center or a storage site exclusively within the country to comply with regulations. Having such an infrastructure may not always be feasible and is a big challenge for cloud providers.

Sunday, July 17, 2011

How to care your Laptop Battery

            Battery is an important part of the Laptop. Because the mobility of the laptop exactly depends on the battery life of the laptop. If the battery has good charging capacity and if it can supply power for a long period the battery may be consider as good battery.
There are many types of batteries available in the market. Following are the most popular and common types of battery.
Lithium-ion (Li-ion) Batteries 
Lithium-ion battery is a new technology of batteries. Most of modern laptops uses Li-ion batteries. It is lighter weight and higher performance. Li-ion batteries are not susceptible  to “Memory Effect”. We will later talk about the “Memory Effect”. Initial condition will effect good life time of Li-ion battery.

Nickel-metal Hydride (NiMH) Batteries 
Although it is susceptible to memory effect, it is less susceptible to memory effect than NiCd Batteries. It should be conditioned once per  2 or 3 week. Condition is fully discharge the battery and fully charge it again.

Nickel Cadmium (NiCd) Batteries 
NiCd is the oldest battery technology. NiCd battery has good performance. But, it is tremendously  susceptible for Memory Effect. Let’s say when we charge the battery we charge it to 90% of the battery capacity. If we doing this over and over again battery tend to keep a memory as 90% is the fully charged state of the battery. Then battery won’t charge in to its full capacity. If we always discharge the battery to 30% of the battery capacity, battery keeps the memory as 30% is the fully discharged state. This is the “Memory Effect” incident and this will reduce the use of battery recourse.

Now, Lest discuss how to care our laptop battery.

  • When you use the battery first time, you should fully charge and discharge (condition cycle) for first three cycles.
  • Keep the battery contact terminal clean always. This helps maintain a good connection between the battery and your laptop.
  • If the battery will not be in use for a month or longer, it is recommended that it be removed from the device and stored in a cool, dry, clean place.
  • Use the AC (alternative current) adapter always you can. There is no any overcharging happen. When the battery completely charged, in every laptop there is mechanism to disconnect the battery from the AC current. Then the laptop will work from the AC power.

  • Condition the battery for every 2 or 3 months. Don’t  charge the battery so that the memory effect happens. This bullet point is not applicable to Li-ion batteries. Li-ion batteries don’t want to condition frequently and those are not affected to Memory effect.
  • Use power management plans available in your system. Turn down the LCD brightness. Set screen saver blank to small time limit as much as.
  • Use suitable RAM size to your laptop. If you have a RAM which is large enough to store your all frequent data, it will save large amount of power. Using hard drive to fetch data always is power exhaustive process.
  • Close all unused software and processes.  
  • Don’t open short-circuit the battery terminals. It will damage the battery permanently.
  • Don’t open the battery cover as the cell contents expose and don’t modify the battery casing. 

Thursday, June 2, 2011

Add the Quick Launch Toolbar in Windows 7

Quick Launch Toolbar is a toolbar which gives the easy access of our favorite locations even without a double clicking. Quick Launch is just a folder on your computer which you can add your own short cuts, files, and folders to. This was placed in right hand side to the start button as part of the task bar in previous Windows versions. In Windows 7, it is not visible to access directly. But the quick launch folder is available also in Widows 7. It only takes a moment to restore the old Quick Launch Toolbar.

  • Right-click the task bar, choose Toolbars > New Toolbar.
  • Copy paste or type: %UserProfile%\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch into the Folder Box and click Select Folder.
  • Now right-click the taskbar, clear Lock the taskbar, and you should see the Quick Launch toolbar, probably to the right.
  • Right-click its divider, clear Show Text and Show Title to minimize the space it takes up.
  • Drag the divider into left if you want to place the Quick Launch bar in the left side of the Task bar. 
Complete the job by right-clicking the bar and selecting View, then Small Icons for a genuine old-fashioned look.

Thursday, May 19, 2011

Useful Windows 7 Keyboard Shortcuts

Win+D – Minimize all windows and show the desktop
Win+E – Launch Explorer with Computer as the focus
Win+F – Launch a search window
Win+G – Cycle through gadgets
Win+L – Lock the desktop
Win+M – Minimize the current window
Win+R – Open the Run window
Win+T – Cycle through task bar opening Aero Peek for each running item
Win+h – Move current window to full screen
Win+U – Open the Ease of Use center
Win+Space – Aero Peek the desktop
Win+Tab – Flip 3D
Win+Pause – Launch System applet
Win+Shift+arrow – Move current window to alternate screen
Win+i – Restore current full-screen window to normal size or minimize current window, if not full-screen
Alt+F4 – with windows closed launches the Shut Down Windows dialog box.
Alt+Tab – Film Strip

Wednesday, May 11, 2011

Easiest and Best way to read RSS feed using Google Chrome

              RSS (Really Simple Syndication) is a web feed format which can be used to publish frequent updates like news, blog posts, comments, etc. By using RSS feed we can quickly get the news and updates. In most of the news sites and bolgs you can see the RSS feed link or RSS logo. If you click there, you can see the RSS page which is formated by XML plain text. Actually it is a XML page. There are RSS readers or feed reader which is web based of desktop based software to read this RSS feed file. Today I am going to introduce you a convenient way to read this RSS feed without using these softwares.

                       This is a google chrome extension called RSS Live Links. Go to the  RSS Live Links page in Google chrome web store and install the extension to your Chrome browser. Then you can see the RSS Live Links logo in the upper right hand side conner in ur google chrome browser.  

                      When you click there you can see the pop-up menu with the available news feed. We can click the option button there and then we have the option page. There we can add new RSS link to subscribe to new news feeds. In option page you can do so may changes. You can add feeds, delete, group, etc.
Option page
                          When you go to a web page which is available news feeds, you can see it in Available feeds in the RSS Live Link extension. By clicking those link, you can just subscribe for that page without searching and copy pasting the RSS link in the web page. RSS Live Link extension refreshes every after the time period which is given as the "Default TTL". That means it reads the XML pages which is given as the RSS link. If there is an update in that page, it sows the audible signal by the extension. By clicking those news feed you can see the headlines of the news items. When you move the courser on to that head lines you can see small window of small preview of that news item.