What is Cloud Computing?
Cloud computing is a technology that allows users to access and use computing resources (such as servers, storage, databases, networking, software, and analytics) over the internet, typically provided by cloud service providers like Amazon Web Services (AWS), Microsoft Azure, and Google Cloud.
What are the key benefits of using cloud computing?
Cloud computing offers benefits such as scalability, cost-efficiency, flexibility, rapid deployment, and the ability to access resources from anywhere with an internet connection.
Explain the difference between IaaS, PaaS, and SaaS.
IaaS (Infrastructure as a Service): Provides virtualized computing resources (e.g., virtual machines, storage, networking) on a pay-as-you-go basis.
PaaS (Platform as a Service): Offers a platform with tools and services for application development, deployment, and management.
SaaS (Software as a Service): Delivers software applications over the internet on a subscription basis, eliminating the need for local installation and maintenance.
What are the deployment models in cloud computing?
The main deployment models are:
Public Cloud: Services are provided by cloud providers and accessible over the internet to the general public.
Private Cloud: Cloud infrastructure is exclusively used by a single organization.
Hybrid Cloud: Combines public and private clouds, allowing data and applications to be shared between them.
What is the difference between horizontal scaling and vertical scaling?
Horizontal Scaling: Involves adding more instances (e.g., virtual machines) to a system to distribute the load. It is typically used in cloud environments and provides better scalability.
Vertical Scaling: Involves increasing the resources (e.g., CPU, RAM) of a single instance to handle increased load. It is limited by the capacity of a single machine.
What is serverless computing, and how does it work?
Serverless computing is a cloud computing model where developers can run code without managing servers. Cloud providers automatically handle server provisioning, scaling, and maintenance based on the code’s execution.
What is the Cloud Security Shared Responsibility Model?
The Cloud Security Shared Responsibility Model defines the division of security responsibilities between cloud providers and customers. Cloud providers are responsible for the security of the cloud infrastructure, while customers are responsible for securing their data and applications.
What is auto-scaling in the cloud, and why is it important?
Auto-scaling is a feature that automatically adjusts the number of resources (e.g., VM instances) based on demand. It ensures optimal performance and cost-efficiency by scaling resources up or down as needed.
Explain the term “Elastic Load Balancing” in the context of cloud services.
Elastic Load Balancing is a service provided by cloud providers that automatically distributes incoming traffic across multiple instances to ensure high availability, fault tolerance, and even resource utilization.
What is a Content Delivery Network (CDN), and how does it improve website performance?
A CDN is a network of distributed servers that cache and deliver web content (e.g., images, videos) to users based on their geographic location. It reduces latency and improves website loading times.
What is the difference between high availability and disaster recovery in the cloud?
High Availability (HA): Ensures that a system is continuously operational with minimal downtime. It typically involves redundancy and failover mechanisms.
Disaster Recovery (DR): Focuses on the ability to recover data and services after a catastrophic event. It involves backup, replication, and recovery procedures.
How can you secure data in transit and at rest in the cloud?
Data in Transit: Use encryption protocols like HTTPS, SSL/TLS for web traffic, and VPNs for private connections.
Data at Rest: Encrypt data stored in cloud storage services and manage encryption keys securely.
Explain the concept of cloud cost optimization.
Cloud cost optimization involves managing and reducing cloud expenses by optimizing resource allocation, leveraging reserved instances, and monitoring usage to eliminate waste.
What is multi-cloud and why would an organization use it?
Multi-cloud refers to using multiple cloud providers or platforms to host different parts of an application or workload. Organizations use multi-cloud strategies to avoid vendor lock-in, increase redundancy, and leverage best-of-breed services from different providers.
Explain what a Virtual Machine (VM) is in cloud computing.
A Virtual Machine (VM) is a software emulation of a physical computer. It allows multiple VMs to run on a single physical host, enabling efficient resource utilization and isolation.
What are the main features of Cloud Computing?
The main features of cloud computing are:
Agility – Huge amounts of computing resources can be provisioned in minutes
Location Independence – Resources can be accessed from anywhere with an internet connection
Better Storage – with cloud storage, there are no limitations of capacity like in physical devices
Multi-Tenancy – resource sharing is possible among a large group of users
Reliability – data backup and disaster recovery become easier and less expensive with cloud computing
Scalability – Cloud allows businesses to scale up and scale down as and when needed
What are Cloud Delivery Models?
Cloud Delivery models are categories of cloud computing, including:
Infrastructure as a Service (IaaS) – the delivery of services like servers, storage, networks, operating systems on request basis.
Platform as a Service (PaaS) – it combines IaaS with an abstracted collection of middleware services, software development, deployment tools. PaaS helps developers to quickly create web or mobile apps on a cloud.
Software as a Service (SaaS) – software applications are delivered on-demand, in a multi-tenant model
Function as a Service (FaaS) – allows end-users to build and run app functionalities on a serverless architecture
What are the different versions of the Cloud?
There are different models to deploy cloud services:
Public Cloud – the set of computer resources like hardware, software, servers, storage, etc., owned and operated by third-party cloud providers for use by businesses or individuals.
Private Cloud – a set of resources owned and operated by an organization for use by its staff, partners, or customers.
Hybrid Cloud – a combination of public and private cloud services.
Name the main constituents of the Cloud ecosystem.
Cloud Consumers
Direct Customers
Cloud Service Providers
What is Cloud Technology?
A Cloud is a virtual space on the internet where users can store digital resources like software, applications, and files. Cloud technology allows computing services including servers, networks, storage, databases, software, analytics, and intelligence to be delivered over the internet. Users can share digital resources across the internet without the restriction of physical location.
What are the main features of Cloud Computing?
The main features of cloud computing are:
Agility – Huge amounts of computing resources can be provisioned in minutes
Location Independence – Resources can be accessed from anywhere with an internet connection
Better Storage – with cloud storage, there are no limitations of capacity like in physical devices
Multi-Tenancy – resource sharing is possible among a large group of users
Reliability – data backup and disaster recovery become easier and less expensive with cloud computing
Scalability – Cloud allows businesses to scale up and scale down as and when needed
What are Cloud Delivery Models?
Cloud Delivery models are categories of cloud computing, including:
Infrastructure as a Service (IaaS) – the delivery of services like servers, storage, networks, operating systems on request basis.
Platform as a Service (PaaS) – it combines IaaS with an abstracted collection of middleware services, software development, deployment tools. PaaS helps developers to quickly create web or mobile apps on a cloud.
Software as a Service (SaaS) – software applications are delivered on-demand, in a multi-tenant model
Function as a Service (FaaS) – allows end-users to build and run app functionalities on a serverless architecture
What are the different versions of the Cloud?
There are different models to deploy cloud services:
Public Cloud – the set of computer resources like hardware, software, servers, storage, etc., owned and operated by third-party cloud providers for use by businesses or individuals.
Private Cloud – a set of resources owned and operated by an organization for use by its staff, partners, or customers.
Hybrid Cloud – a combination of public and private cloud services.
Name the main constituents of the Cloud ecosystem.
Cloud Consumers
Direct Customers
Cloud Service Providers
Who are the cloud service providers?
Cloud service providers are the commercial vendors or companies that develop their own cloud services capabilities and sell the services to cloud consumers.
Who are Direct Customers?
Direct customers are users who often use the services developed by your business within a cloud environment. They do not know if you’re using a public or private cloud.
Who are cloud consumers?
Cloud consumers are the individuals or groups within a business unit that use the various cloud services provided to get a task done.
Describe the Cloud Computing Architecture
Cloud computing architecture is divided into:
Front end – used by the client and consisting of client-side interfaces and applications needed to access cloud computing platforms. It includes web servers like Chrome, Firefox, tablets, mobile devices.
Back end – used by a service provider to manage all resources needed for providing Cloud computing services. Includes data storage, virtual machines, servers, deploying models, etc.
The different components of the cloud architecture are:
Client Infrastructure – provides GUI for cloud interaction
Application – software or platform
Service – a type of service accessed
What are the Cloud Storage Levels?
The common levels of cloud data storage are:
Files
Blocks
Datasets
Objects
Name the serverless components in cloud computing.
Serverless components enable users to create applications without the complexity of managing physical infrastructure. Codes can be written without the provision for a server.
Serverless machines tend to virtual machines and container management.
Serverless components also take care of multi-threading hardware allocation.
List the advantages and disadvantages of serverless computing.
Advantages:
Cost-effective
Simplified operations
Increases Productivity
Scalable
Disadvantages:
Can cause latency in response
Not suited for high-computing operations due to resource limitations
Not very secure
Debugging can be challenging
What are cloud-enabling technologies?
Broadband Networks
Virtualization
Data Centre
Web Technology
Multitenant Technology
Service Technology
Define microservices.
Microservices is the process of creating applications that include code that is independent of each other and of the inherent developing platform.
Discuss the importance of microservices for a true cloud environment.
Microservices provide benefits like:
A microservice is designed to serve a specific purpose, so application development becomes simple.
It is easier and faster to make code changes using microservices because the changes are smaller and simpler compared to a complex integrated application.
They are scalable; hence easy to deploy additional instances or change of service.
A microservice is fully tested and validated. Thus, developers can presume the integrity of new applications without continual testing.
What is a cloud usage monitor?
It is an autonomous lightweight software program that gathers and processes IT resource usage data. These monitors can exist in various formats like Monitoring Agent, Resource Agent, Polling Agent.
How does the monitoring agent monitor cloud usage?
A monitoring agent is an intermediary and event-driven program that thrives as a service agent and exists along the communication paths. It monitors and analyses dataflows and is used to measure network traffic and message metrics.
How do resource agents monitor cloud usage?
A resource agent is a processing module used to collect usage data through event-driven interactions with resource software. It is used to check usage metrics depending on pre-defined observable events.
How does a polling agent monitor cloud usage?
A polling agent refers to a processing module that assembles data related to cloud service usage by polling IT resources. It can also timely monitor the It resource status.
What are Cloud-native applications?
It is a software framework characterized by containers, microservices, dynamic orchestration, and continued software delivery. Every part of a cloud-native publication contains its individual container and is dynamically coordinated with other containers.
How does cloud-native foundation define Cloud-native applications?
Cloud-native applications are defined as:
Container packaged – meaning standard container packaging format used to package applications.
Dynamically managed – standard format to discover, deploy and scale applications.
Microservices oriented – decompose applications into modular, independent services
What is Edge Computing?
Unlike Cloud, Edge computing concerns with physical location and latency issues. Edge is very common in IoT scenarios.
What is API Gateway?
API gateway allows a number of APIs to come together as a single gateway for a uniform user experience. The API gateway centrally manages the APIs and provides enterprise-level security. The gateway handles common tasks like statistics, rate limiting, user authentication.
What is Rate Limiting?
A strategy to limit network traffic by putting a limit on how often someone can repeat an action in a certain timeframe. Rate limiting can help eliminate malicious activities and bot impacts.
What is encapsulation?
In cloud computing, encapsulation means packaged software code along with all of its dependencies, such that it can consistently run both on clouds and on-premises.
Name the different data centers deployed for cloud computing.
Containerized Datacentres
Low-Density Datacentres
What are Containerised Datacentres?
These are traditional data centers that allow a great deal of customization with servers, mainframes, and other resources.
What are Low-Density Datacentres?
These data centers are optimized to provide a high level of performance. When the space constraint is removed, there is high density in these data centers.
Name some issues with Cloud Computing.
Security Issues
Legal and Compliance Issues
Data Management Issues
Performance and Quality of Service Related Issues
How Resource Replication takes place in Cloud Computing?
Resource Replication involves creating multiple instances of the same IT resource. It is usually done when there’s a need to enhance the availability and performance of a resource. Virtualization technology helps implement resource replication.
Define and explain the three basic types of cloud services and the AWS products that are built based on them?
The three basic types of cloud services are:
- Computing
- Storage
- Networking
Here are some of the AWS products that are built based on the three cloud service types:
Computing – These include EC2, Elastic Beanstalk, Lambda, Auto-Scaling, and Lightsat.
Storage – These include S3, Glacier, Elastic Block Storage, Elastic File System.
Networking – These include VPC, Amazon CloudFront, Route53
What is auto-scaling?
Auto-scaling is a function that allows you to provision and launch new instances whenever there is a demand. It allows you to automatically increase or decrease resource capacity in relation to the demand.
What is geo-targeting in CloudFront?
Geo-Targeting is a concept where businesses can show personalized content to their audience based on their geographic location without changing the URL. This helps you create customized content for the audience of a specific geographical area, keeping their needs in the forefront.
How do you upgrade or downgrade a system with near-zero downtime?
You can upgrade or downgrade a system with near-zero downtime using the following steps of migration:
- Open EC2 console
- Choose Operating System AMI
- Launch an instance with the new instance type
- Install all the updates
- Install applications
- Test the instance to see if it’s working
- If working, deploy the new instance and replace the older instance
What are the tools and techniques that you can use in AWS to identify if you are paying more than you should be, and how to correct it?
You can know that you are paying the correct amount for the resources that you are using by employing the following resources:
Check the Top Services Table
It is a dashboard in the cost management console that shows you the top five most used services. This will let you know how much money you are spending on the resources in question.
Cost Explorer
There are cost explorer services available that will help you to view and analyze your usage costs for the last 13 months. You can also get a cost forecast for the upcoming three months.
AWS Budgets
This allows you to plan a budget for the services. Also, it will enable you to check if the current plan meets your budget and the details of how you use the services.
Cost Allocation Tags
This helps in identifying the resource that has cost more in a particular month. It lets you organize your resources and cost allocation tags to keep track of your AWS costs.
Is there any other alternative tool to log into the cloud environment other than console?
- Putty
- AWS CLI for Linux
- AWS CLI for Windows
- AWS CLI for Windows CMD
- AWS SDK
- Eclipse
What services can be used to create a centralized logging solution?
The essential services that you can use are Amazon CloudWatch Logs, store them in Amazon S3, and then use Amazon Elastic Search to visualize them. You can use Amazon Kinesis Firehose to move the data from Amazon S3 to Amazon Elastic Search.
What is a DDoS attack, and what services can minimize them?
DDoS is a cyber-attack in which the perpetrator accesses a website and creates multiple sessions so that the other legitimate users cannot access the service. The native tools that can help you deny the DDoS attacks on your AWS services are:
- AWS Shield
- AWS WAF
- Amazon Route53
- Amazon CloudFront
- ELB
- VPC
How do you set up a system to monitor website metrics in real-time in AWS?
Amazon CloudWatch helps you to monitor the application status of various AWS services and custom events. It helps you to monitor:
- State changes in Amazon EC2
- Auto-scaling lifecycle events
- Scheduled events
- AWS API calls
- Console sign-in events
What are the different types of virtualization in AWS, and what are the differences between them?
The three major types of virtualization in AWS are:
Hardware Virtual Machine (HVM)
It is a fully virtualized hardware, where all the virtual machines act separate from each other. These virtual machines boot by executing a master boot record in the root block device of your image.
Paravirtualization (PV)
Paravirtualization-GRUB is the bootloader that boots the PV AMIs. The PV-GRUB chain loads the kernel specified in the menu.
Paravirtualization on HVM
PV on HVM helps operating systems take advantage of storage and network I/O available through the host.
Name some of the AWS services that are not region-specific
AWS services that are not region-specific are:
- IAM
- Route 53
- Web Application Firewall
- CloudFront
What is CloudWatch?
The Amazon CloudWatch has the following features:
Depending on multiple metrics, it participates in triggering alarms.
Helps in monitoring the AWS environments like CPU utilization, EC2, Amazon RDS instances, Amazon SQS, S3, Load Balancer, SNS, etc.
What is an Elastic Transcoder?
To support multiple devices with various resolutions like laptops, tablets, and smartphones, we need to change the resolution and format of the video. This can be done easily by an AWS Service tool called the Elastic Transcoder, which is a media transcoding in the cloud that exactly lets us do the needful. It is easy to use, cost-effective, and highly scalable for businesses and developers.
Define Amazon EC2 regions and availability zones?
Availability zones are geographically separate locations. As a result, failure in one zone has no effect on EC2 instances in other zones. When it comes to regions, they may have one or more availability zones. This configuration also helps to reduce latency and costs.
Explain Amazon EC2 root device volume?
The image that will be used to boot an EC2 instance is stored on the root device drive. This occurs when an Amazon AMI runs a new EC2 instance. And this root device volume is supported by EBS or an instance store. In general, the root device data on Amazon EBS is not affected by the lifespan of an EC2 instance.
Explain what AWS is?
AWS stands for Amazon Web Service; it is a collection of remote computing services also known as a cloud computing platform. This new realm of cloud computing is also known as IaaS or Infrastructure as a Service.
Mention what the key components of AWS are?
The key components of AWS are
Route 53:A DNS web service
Simple E-mail Service:It allows sending e-mail using RESTFUL API call or via regular
SMTP
Identity and Access Management:It provides enhanced security and identity management for your AWS account
Simple Storage Device or (S3):It is a storage device and the most widely used AWS service
Elastic Compute Cloud (EC2): It provides on-demand computing resources for hosting applications. It is handy in case of unpredictable workloads
Elastic Block Store (EBS):It offers persistent storage volumes that attach to EC2 to allow you to persist data past the lifespan of a single Amazon EC2 instance
CloudWatch: To monitor AWS resources, It allows administrators to view and collect key Also, one can set a notification alarm in case of trouble.
Explain what S3 is?
S3 stands for Simple Storage Service. You can use S3 interface to store and retrieve any amount of data, at any time and from anywhere on the web. For S3, the payment model is “pay as you go.”
What is AMI?
AMI stands for Amazon Machine Image. It’s a template that provides the information (an operating system, an application server, and applications) required to launch an instance, which is a copy of the AMI running as a virtual server in the cloud. You can launch instances from as many different AMIs as you need.
Mention what the relationship between an instance and AMI is?
From a single AMI, you can launch multiple types of instances. An instance type defines the hardware of the host computer used for your instance. Each instance type provides different computer and memory capabilities. Once you launch an instance, it looks like a traditional host, and we can interact with it as we would with any computer.
What does an AMI include?
An AMI includes the following things
A template for the root volume for the instance
Launch permissions decide which AWS accounts can avail the AMI to launch instances .A block device mapping that determines the volumes to attach to the instance when it is launched.
How can you send a request to Amazon S3?
Amazon S3 is a REST service, and you can send a request by using the REST API or the AWS SDK wrapper libraries that wrap the underlying Amazon S3 REST API.
What are the storage class available in Amazon s3?
Storage classes available with Amazon s3 are:
Amazon S3 standard
Amazon S3 standard-infrequent Access
Amazon S3 Reduced Redundancy Storage
Amazon Glacier
How many buckets can you create in AWS by default?
By default, you can create up to 100 buckets in each of your AWS accounts.
Explain can you vertically scale an Amazon instance? How?
Yes, you can vertically scale on Amazon instance. For that
Spin up a new larger instance than the one you are currently running.
Pause that instance and detach the root webs volume from the server and discard.
Then stop your live instance and detach its root volume.
Note the unique device ID and attach that root volume to your new server And start it again.
Explain what T2 instances is?
T2 instances are designed to provide moderate baseline performance and the capability to burst to higher performance as required by the workload.
In VPC with private and public subnets, database servers should ideally be launched
into which subnet?
With private and public subnets in VPC, database servers should ideally launch into private subnets.
Mention what the security best practices for Amazon EC2 are?
For secure Amazon EC2 best practices, follow the following steps
Use AWS identity and access management to control access to your AWS resources Restrict access by allowing only trusted hosts or networks to access ports on your instance
Review the rules in your security groups regularly
Only open up permissions that you require
Disable password-based login, for example, launched from your AMI
Explain how the buffer is used in Amazon web services?
The buffer is used to make the system more robust to manage traffic or load by synchronizing different component. Usually, components receive and process the requests in an unbalanced way. With the help of buffer, the components will be balanced and will work at the same speed to provide faster services.
While connecting to your instance what are the possible connection issues one might
face?
The possible connection errors one might encounter while connecting instances are
Connection timed out
User key not recognized by the server
Host key not found, permission denied
An unprotected private key file
Server refused our key or No supported authentication method available
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