Category: Subjects

Types of Cloud Computing

Cloud Computing

Cloud Computing-

 

Before you go through this article, make sure that you have gone through the previous article on Basics of Cloud Computing.

 

We have discussed-

  • Cloud computing is a general term for the delivery of computing services such as servers, storage, databases etc over the internet.
  • Companies offering these computing services are called cloud providers and typically charge for cloud computing services based on usage.

 

In this article, we will discuss types of cloud computing.

 

Types of Cloud Computing-

 

Cloud computing is classified either on the basis of cloud location or on the service that the cloud is offering.

 

I) Based on a cloud location (Cloud Deployment Models):

 

On the basis of a cloud location, we can classify it as-

 

1. Public cloud:

 

  • Public cloud means that the whole computing infrastructure is located on the premises of a cloud computing company that offers the cloud service and the resources are shared among many customers.
  • As public clouds use shared resources, they are most vulnerable to various attacks.

 

2. Private cloud:

 

  • Private cloud means that the whole computing infrastructure is used solely by one customer or organization.
  • The security and control level is highest while using a private network.

 

3. Hybrid cloud:

 

  • Hybrid cloud means using both public and private clouds depending on their purpose.
  • For example- public cloud can be used to interact with customers while keeping their data secured through a private cloud.

 

4. Community cloud:

 

  • A community cloud can be a public cloud, private cloud or Hybrid cloud.
  • A community cloud is designed to meet the needs of a community.Such communities involve people or organizations that have shared interests.

 

II) Based on a service that the cloud is offering / Types of cloud service development:

 

On the basis of a service that the cloud is offering, we can classify it as-

 

1. Infrastructure-as-a-Service (IaaS):

 

  • Infrastructure-as-a-Service (IaaS) is a model in which the vendors make available resources such as server space, network equipment’s, storage space etc for the clients which can be scaled up and down depending on the needs of the clients.
  • The clients simply for the service as subscription fees on contractual basis instead of owing such IT infrastructure.
  • Examples are- Amazon, Rackspace etc.

 

2. Platform-as-a-Service (PaaS):

 

  • Platform-as-a-Service (PaaS) is a model in which the vendors offers a development platform which includes operating system, programming language execution environment, database , web server etc for the clients to build applications on the web and the clients need not download or install such software on their PCs.
  • Examples are- Google App Engine, Microsoft Azzure etc.

 

3. Software-as-a-Service (SaaS):

 

  • Software-as-a-Service (SaaS) is a model in which the vendors host the applications on the internet and users can access those applications on a pay-per-use basis.
  • Examples of such services include widely used Gmail or Google Docs.

 

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Advantage & Disadvantage of Cloud Computing

Cloud Computing

Cloud Computing-

 

Before you go through this article, make sure that you have gone through the previous article on Basics of Cloud Computing.

 

We have discussed-

  • Cloud computing is a general term for the delivery of computing services such as servers, storage, databases etc over the internet.
  • Companies offering these computing services are called cloud providers and typically charge for cloud computing services based on usage.

 

In this article, we will discuss the advantages and disadvantages of cloud computing.

 

Advantages of Cloud Computing-

 

Some of the advantages of cloud computing are as follows-

 

1. Cost efficient-

 

Cloud computing is probably the most cost efficient method to use, maintain and upgrade. Traditional desktop software costs companies a lot in terms of finance. On the other hand, the cloud is available at much cheaper rates and hence significantly lowers the company’s IT expenses.

 

2. Unlimited Storage-

 

Storing information in the cloud gives you almost unlimited storage capacity. Hence, you need not worry about running out of storage space.

 

3. Backup and Recovery-

 

Since all your data is stored in the cloud, backing it up and restoring the same is relatively much easier than storing the same on a physical device. Furthermore, most cloud service providers are usually competent enough to handle recovery of information. This makes the entire process of backup and recovery much simpler than other traditional methods of data storage.

 

4. Easy access to information-

 

Once you register yourself in the cloud, you can access the information from anywhere, where there is an Internet connection. This convenient feature lets you move beyond time zone and geographic location issues.

 

5. Quick deployment-

 

Cloud computing gives you the advantage of quick deployment. Once you opt for this method of functioning, your entire system can be fully functional in a matter of a few minutes.

 

Disadvantages of Cloud Computing-

 

Some of the most important challenges of cloud computing are-

 

1. Security and Privacy-

 

The main challenge to cloud computing is how it addresses the security and privacy concerns of businesses thinking of adopting it. Hacking and various attacks to cloud infrastructure would affect multiple clients even if only one site is attacked.

 

2. Reliability and Availability-

 

Cloud providers still lack round-the-clock service which results in frequent outages. It is important to monitor the service being provided using internal or third-party tools.

 

3. Vendor Lock-in-

 

Businesses should have the leverage of migrating in and out of the cloud and switching service providers freely whenever they want and there should be no lock-in period.

 

4. Lack of executive support-

 

In one way or another, a lack of support generally comes down to fear, uncertainty and doubt.

 

5. Lack of skills, knowledge and expertise-

 

Many IT organizations may not have the necessary tools or resources to implement, monitor and manage cloud solutions.

 

6. Performance and bandwidth cost-

 

Businesses can save money on hardware but they have to spend more for the bandwidth. This can be a low cost for smaller applications but can be significantly high for the data intensive applications. Because of this, many businesses are waiting for a reduced cost before switching to the cloud.

 

7. Service Quality-

 

Service quality is one of the biggest factors for the enterprises not moving their business applications to cloud. They feel that the SLAs provided by the cloud providers today are not sufficient to guarantee the requirements for running production applications on cloud especially related to the performance, availability and scalability.

 

Next Article- Types of Cloud Computing

 

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Cloud Computing | Examples | Features

Cloud Computing

Cloud Computing-

 

Cloud computing is a general term for the delivery of computing services such as servers, storage, databases etc over the internet.

Companies offering these computing services are called cloud providers and typically charge for cloud computing services based on usage.

 

Example-

 

Google hosts a cloud that consists of both smallish PCs and larger servers. Google’s cloud is a private one (that is, Google owns it) that is publicly accessible by Google’s users.

 

Feature of Cloud Computing-

 

Cloud computing is-

  • user-centric
  • task-centric
  • powerful
  • accessible
  • intelligent
  • programmable

 

1. Cloud Computing Is User-Centric:

 

Once you as a user are connected to the cloud, whatever is stored there, be it documents, messages, images, applications, whatever becomes yours. In addition, you can also share it with others.

 

2. Cloud Computing Is Task-Centric:

 

Instead of focusing on the application and what it can do, the focus is on what you need done and how the application can do it for you.

 

3. Cloud Computing Is Powerful:

 

Connecting hundreds or thousands of computers together in a cloud creates a wealth of computing power that is impossible with a single desktop PC.

 

4. Cloud Computing Is Accessible:

 

Because data is stored in the cloud, users can instantly retrieve more information from multiple repositories. You’re not limited to a single source of data as you are with a desktop PC.

 

5. Cloud Computing Is Intelligent:

 

With all the various data stored on the computers in a cloud, data mining and analysis are necessary to access that information in an intelligent manner.

 

6. Cloud Computing Is Programmable:

 

Many of the tasks necessary with cloud computing must be automated.

 

For example, to protect the integrity of the data, information stored on a single computer in the cloud must be replicated on other computers in the cloud. If that one computer goes offline, the cloud’s programming automatically redistributes that computer’s data to a new computer in the cloud.

 

Next Article- Advantages and Disadvantages of Cloud Computing

 

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System Bus in Computer Architecture

Computer Organization and Architecture

System Bus in Computer Architecture-

 

What Is A System Bus?

 

  • A bus is a set of electrical wires (lines) that connects the various hardware components of a computer system.
  • It works as a communication pathway through which information flows from one hardware component to the other hardware component.

 

A bus that connects major components (CPU, memory and I/O devices) of a computer system is called as a System Bus.

 

 

 

Why Do We Need Bus?

 

  • A computer system is made of different components such as memory, ALU, registers etc.
  • Each component should be able to communicate with other for proper execution of instructions and information flow.
  • If we try to implement a mesh topology among different components, it would be really expensive.
  • So, we use a common component to connect each necessary component i.e. BUS.

 

Components Of A System Bus-

 

The system bus consists of three major components-

 

 

  1. Data Bus
  2. Address Bus
  3. Control Bus

 

Let us learn about each component one by one.

 

1) Data Bus-

 

  • As the name suggests, data bus is used for transmitting the data / instruction from CPU to memory/IO and vice-versa.
  • It is bi-directional.

 

Data Bus Width

 

  • The width of a data bus refers to the number of bits (electrical wires) that the bus can carry at a time.
  • Each line carries 1 bit at a time. So, the number of lines in data bus determine how many bits can be transferred parallely.
  • The width of data bus is an important parameter because it determines how much data can be transmitted at one time.
  • The wider the bus width, faster would be the data flow on the data bus and thus better would be the system performance.

 

Examples-

  • A 32-bit bus has thirty two (32) wires and thus can transmit 32 bits of data at a time.
  • A 64-bit bus has sixty four (64) wires and thus can transmit 64 bits of data at a time.

 

2) Control Bus-

 

  • As the name suggests, control bus is used to transfer the control and timing signals from one component to the other component.
  • The CPU uses control bus to communicate with the devices that are connected to the computer system.
  • The CPU transmits different types of control signals to the system components.
  • It is bi-directional.

 

What Are Control & Timing Signals?

 

Control signals are generated in the control unit of CPU.

Timing signals are used to synchronize the memory and I/O operations with a CPU clock.

 

Typical control signals hold by control bus-

  • Memory read – Data from memory address location to be placed on data bus.
  • Memory write – Data from data bus to be placed on memory address location.
  • I/O Read – Data from I/O address location to be placed on data bus.
  • I/O Write – Data from data bus to be placed on I/O address location.

 

Other control signals hold by control bus are interrupt, interrupt acknowledge, bus request, bus grant and several others.

The type of action taking place on the system bus is indicated by these control signals.

 

Example-

 

When CPU wants to read or write data, it sends the memory read or memory write control signal on the control bus to perform the memory read or write operation from the main memory. Similarly, when the processor wants to read from an I/O device, it generates the I/O read signal.

 

3) Address Bus-

 

  • As the name suggests, address bus is used to carry address from CPU to memory/IO devices.
  • It is used to identify the particular location in memory.
  • It carries the source or destination address of data i.e. where to store or from where to retrieve the data.
  • It is uni-directional.

 

Example-

 

When CPU wants to read or write data, it sends the memory read or memory write control signal on the control bus to perform the memory read or write operation from the main memory and the address of the memory location is sent on the address bus.

If CPU wants to read data stored at the memory location (address) 4, the CPU send the value 4 in binary on the address bus.

 

Address Bus Width

 

  • The width of address bus determines the amount of physical memory addressable by the processor.
  • In other words, it determines the size of the memory that the computer can use.
  • The wider is the address bus, the more memory a computer will be able to use.
  •  The addressing capacity of the system can be increased by adding more address lines.

 

Examples-

  • An address bus that consists of 16 wires can convey 216 (= 64K) different addresses.
  • An address bus that consists of 32 wires can convey 232 (= 4G) different addresses.

 

PRACTICE PROBLEMS BASED ON SYSTEM BUS-

 

Problem-01:

 

Which of the following system bus is used to designate the source or destination of the data on the bus itself?

  1. Control bus
  2. Data bus
  3. Address bus
  4. System bus

 

Solution-

 

The correct option is (C) Address bus.

Address bus carries the source or destination address of data i.e. where to store or from where to retrieve the data.

 

Problem-02:

 

The bus which is used to transfer data from main memory to peripheral device is-

  1. Data bus
  2. Input bus
  3. DMA bus
  4. Output bus

 

Solution-

 

The correct option is (A) Data bus.

Data bus carries data / instruction from CPU to memory/IO and vice-versa.

 

Problem-03:

 

How many memory locations a system with a 32-bit address bus can address?

  1. 28
  2. 216
  3. 232
  4. 264

 

Solution-

 

The correct option is (C) 232.

232 memory locations can be addressed by a 32-bit address bus.

 

Problem-04:

 

How many bits can be transmitted at a time using a bus with 32 data lines?

  1. 8 bits
  2. 16 bits
  3. 32 bits
  4. 1024 bits

 

Solution-

 

Each line carries one bit. So, a bus with 32 data lines can transmit 32 bits at a time.

 

Problem-05:

 

A microprocessor has a data bus with 64 lines and an address bus with 32 lines. The maximum number of bits that can be stored in memory is-

  1. 32 x 212
  2. 32 x 264
  3. 64 x 232
  4. 64 x 264

 

Solution-

 

The correct option is (C) 64 x 232.

The amount of blocks that could be located is 232. Now, since data bus has 64 lines, so each block is 64 bits. Thus, maximum number of bits stored in memory is 232 x 64 bits.

 

Problem-06:

 

The address bus with a ROM of size 1024 x 8 bits is-

  1. 8 bits
  2. 10 bits
  3. 12 bits
  4. 16 bits

 

Solution-

 

The correct option is (B) 10 bits.

The size of the ROM is 1024 x 8 = 210 x 8. Here, 10 indicates the address bus and 8 indicates the data bus width.

 

Problem-07:

 

The data bus width of a ROM of size 2048 x 8 bits is-

  1. 8
  2. 10
  3. 12
  4. 16

 

Solution-

 

The correct option is (A) 8.

The size of the ROM is 2048 x 8 = 211 x 8. Here, 11 indicates the address bus and 8 indicates the data bus width.

 

To gain better understanding about System Bus in Computer Architecture,

Watch this Video Lecture

 

Next Article- Pipelining in Computer Architecture

 

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Arithmetic Sequence Explained

Mathematics

Arithmetic Sequence Explained With Nth Term & Common Difference-

 

Arithmetic sequence is a topic of mathematics. Often, students get confused when calculating arithmetic sequence because of the nth term and common difference.

 

In this post, we will learn about the basic concept of arithmetic sequence, how to find arithmetic sequence, nth term and common difference. We will also calculate arithmetic sequence with step-by-step examples. However, before moving onto the topic, let’s learn about the general concept of sequence.

 

What Is A Sequence?

 

Sequence usually has patterns that allow us to predict what the next term might be. Ordered list of numbers is called as a sequence. Each number in a sequence is called a term.

 

 

Example-01:

 

3, 5, 7, …

In this sequence, add 2 to get the next number.

 

 

Three dot means sequence moving on up to infinite numbers even through we only see a few terms e.g., the fourth term of this sequence will be nine and the fifth term will be 11 and so on.

 

 

Example-02:

 

21, 16, 11, 6, …

In this sequence, subtract five to get the next term.

 

 

Sequence term should follow the sum to get the next term or subtract, multiply, division. For example-

 

Sequence

Pattern
4, 11, 18, 25, … Add seven to the previous term
100, 96, 92, 88, … Subtract four the previous term
4, 12, 36, 108, … Multiply the previous term by three
4, 20, 10, 5, … Divide the previous term by two

 

What Is Arithmetic Sequence?

 

An arithmetic sequence is a sequence in which each term increases or decreases by adding or subtracting a constant value called as common difference (d).

OR

The pattern that involves adding or subtracting a constant number to the previous term to get next term. Sequence with such  a pattern is called arithmetic sequence.

 

If the common difference between the terms is positive, we say that the sequence is increasing.

If the common difference between the terms is negative, we say that the sequence is decreasing.

 

Example Of Increasing Sequence-

 

3, 5, 7, …

In this sequence, the common difference between the terms is 2 which is a positive number so the sequence is increasing.

 

 

Example Of Decreasing Sequence-

 

-2, -5, -8, -11, …

In this sequence, the common difference between the terms is -3 which is a negative number so the sequence is decreasing.

 

 

Arithmetic Sequence Formula-

 

If you want to find any term or the nth term of the arithmetic sequence, we use this formula of arithmetic sequence. According to this formula, we have-

an= a1 + (n-1) d

Here,

an = nth term of the sequence

a1= first term of the sequence

n = number of sequences

d = common difference between the consecutive terms

 

The above formula is used in Arithmetic Sequence Calculator to implement the accurate calculations of arithmetic sequence, common difference, and nth term.

 

How To Find Arithmetic Sequence?

 

In this section, we will see examples for the calculation of arithmetic sequence, common difference, and nth term.

 

Example-01:

 

Find the nth term and sum of arithmetic sequence of 10 number of terms if the first term is 4 and common difference is 5.

 

Solution-

 

Step-01:

 

Using the given information, we have-

a1 = 4

n = 10

d = 5

 

Step-02:

 

Put the values in the arithmetic sequence formula. Then, we have-

an  = 4 + (10-1) (5)

     = 4 + 9(5)

     = 4 + 45

     = 49

 

Thus, nth term = 49.

 

Step-03:

 

Add the common difference to the first term to get the sequence. Then, we have-

a1 = 4

a2 = a1 + d = 4 + 5 = 9

a3 = a2 + d = 9 + 5 = 14

a4 = a3 + d = 14 + 5 = 19

a5 = a4 + d = 19 + 5 = 24

a6 = a5 + d = 24 + 5 = 29

a7 = a6 + d = 29 + 5 = 34

a8 = a7 + d = 34 + 5 = 39

a9 = a8 + d = 39 + 5 = 44

a10 = a9 + d = 44 + 5 = 49

 

Example-02:

 

Find the nth term and sum of arithmetic sequence of 12 numbers of terms if the first term is 3 and common difference is 5.

 

Solution-

 

Step-01:

 

Using the given information, we have-

a1 = 3

n = 12

d = 5

 

Step-02:

 

Put the values in the arithmetic sequence formula. Then, we have-

an = 3 + (12-1) (5)

= 3 + 11(5)

= 3 + 55

= 58

 

Thus, nth term = 58.

 

Step-03:

 

Add the common difference to the first term to get the sequence. Then, we have-

a1 = 4

a2 = a1 + d = 3 + 5 = 8

a3 = a2 + d = 8 + 5 = 13

a4 = a3 + d = 13 + 5 = 18

a5 = a4 + d = 18 + 5 = 23

a6 = a5 + d = 23 + 5 = 28

a7 = a6 + d = 28 + 5 = 33

a8 = a7 + d = 33 + 5 = 38

a9 = a8 + d = 38 + 5 = 43

a10 = a9 + d = 43 + 5 = 48

a11 = a10 + d = 48 + 5 = 53

a12 = a11 + d = 53 + 5 = 58

 

We can find any term of the sequence by using arithmetic sequence formula e.g., 120th term 500th term etc.

 

Example-03:

 

Find the 120th term of arithmetic sequence if the first term is 8 and common difference is 5.

 

Solution-

 

Step-01:

 

Using the given information, we have-

a1 = 8

n = 120

d = 5

 

Step-02:

 

Put the values in the arithmetic sequence formula. Then, we have-

an = 8 + (120-1) (5)

= 8 + 119(5)

= 8 + 595

= 603

 

Thus, 120th term = 603.

 

Example-04:

 

Find the 500th term of arithmetic sequence if the first term is 9 and common difference is 7.

 

Solution-

 

Step-01:

 

Using the given information, we have-

a1 = 9

n = 500

d = 7

 

Step-02:

 

Put the values in the arithmetic sequence formula. Then, we have-

an = 9 + (500-1) (7)

= 9 + 499(5)

= 9 + 2595

= 2604

 

Thus, 500th term = 2604.

 

Verify the above answer using the online nth Term Calculator.

 

Summary-

 

As you have witnessed, arithmetic sequence is not that difficult or confusing to calculate. Once you have grabbed the core concept of the topic, you will easily find the sequence, nth term and common difference using the formula.