Cloud Infrastructure ইন্টারভিউ প্রশ্ন

Benefit: Real-time insights for rapid issue resolution. Strategy: Leverage Azure Monitor and Application Insights.

Cloud delivery models are models that represent the computing environments. These are as follows:

• Infrastructure as a Service (IaaS): Infrastructure as a Service (IaaS) is the delivery of services, including an operating system, storage, networking, and various utility software elements, on a request basis.
• Platform as a Service (PaaS): Platform as a Service (PaaS) is a mechanism for combining Infrastructure as a Service with an abstracted set of middleware services, software development, and deployment tools. These allow the organization to have a consistent way to create and deploy applications on a cloud or on-premises environment.
• Software as a Service (SaaS): Software as a Service (SaaS) is a business application created and hosted by a provider in a multi-tenant model.
• Function as a Service (FaaS): Function as a Service (FaaS) gives a platform for customers to build, manage and run app functionalities without the difficulty of maintaining infrastructure. One can thus achieve a "serverless" architecture.

Cloud storage device mechanisms provide common levels of data storage, such as:

• Files – These are collections of data that are grouped into files that are located in folders.
• Blocks – A block is the smallest unit of data that is individually accessible. It is the lowest level of storage and the closest to the hardware.
• Datasets – Data sets organized into a table-based, delimited, or record format.
• Objects – Data and the associated metadata with it are organized as web-based resources.

Each of the above data storage levels is associated with a certain type of technical interface. This interface corresponds to a particular type of cloud storage device and the cloud storage service used to expose its API.

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.

A cloud is a combination of services, networks, hardware, storage, and interfaces that helps in delivering computing as a service. It broadly has three users. These are the end-user, business management user, and cloud service, provider. The end-user is the one who uses the services provided by the cloud. The responsibility of the data and the services provided by the cloud is taken by the business management user in the cloud. The one who takes care of or is responsible for the maintenance of the IT assets of the cloud is the cloud service provider. The cloud acts as a common center for its users to fulfill their computing needs.

A VPC is the best way of connecting to your cloud resources from your own data center. Once you connect your datacenter to the VPC in which your instances are present, each instance is assigned a private IP address that can be accessed from your data center. That way, you can access your public cloud resources as if they were on your own private network.

The following are some of the key features of cloud computing:

• Agility: Helps in quick and inexpensive re-provisioning of resources.
• Location Independence: This means that the resources can be accessed from everywhere.
• Multi-Tenancy: The resources are shared amongst a large group of users.
• Reliability: Resources and computation can be dependable for accessibility.
• Scalability: Dynamic provisioning of data helps in scaling.

Benefit: Protect essential data. Strategy: Use Azure Backup or managed database services.

Amazon Route 53 is a scalable and highly available Domain Name System (DNS). The name refers to TCP or UDP port 53, where DNS server requests are addressed.

Benefit: Minimizes latency in different geographic regions. Strategy: Deploy app instances in different regions.

• Operating System Disks: Azure's default storage offering is termed Hard Disk Drive (HDD). You can opt for Solid State Drive (SSD) if your VM size supports it.
• Data Disks: Can be scaled to keep up with your storage needs.

Microservices is a process of developing applications that consist of code that is independent of each other and of the underlying developing platform. Each microservice runs a unique process and communicates through well-defined and standardized APIs, once created. These services are defined in the form of a catalog so that developers can easily locate the right service and also understand the governance rules for usage.

Amazon Web Services (AWS) is a cloud computing platform that offers a vast range of services, including computing power, storage, and databases, to help businesses scale and grow more cost-effectively.

Key Features of AWS

1. Scalability and Elasticity: AWS provides tools that allow for both vertical and horizontal scaling, as well as the ability to auto-scale based on demand.

1. Global Reach: With data centers in multiple geographic regions, AWS enables businesses to operate on a global scale while remaining compliant with local regulations.

1. Pay-As-You-Go Pricing: This flexible pricing model allows users to pay only for the resources they consume, reducing upfront costs.

1. Security and Compliance: AWS offers a variety of security tools and features to help protect data, as well as compliance with numerous industry standards.

1. Hybrid Capabilities: AWS supports hybrid architectures, allowing businesses to integrate their existing on-premises solutions with the cloud.

1. Artificial Intelligence and Machine Learning: With AWS, businesses can harness the power of AI and ML through accessible services for data processing, analysis, and more.

1. Developer Tools: From code repository management to continuous integration and deployment, AWS provides a comprehensive suite of developer-centric services.

1. Internet of Things (IoT): AWS offers capabilities for managing and processing IoT data, connecting devices securely to the cloud.

While you may think that both stopping and terminating are the same, there is a difference. When you stop an EC2 instance, it performs a normal shutdown on the instance and moves to a stopped state. However, when you terminate the instance, it is transferred to a stopped state, and the EBS volumes attached to it are deleted and can never be recovered.

Identity and Access Management (IAM) is a web service for securely controlling access to AWS services. IAM lets you manage users, security credentials such as access keys, and permissions that control which AWS resources users and applications can access.

EC2 is short for Elastic Compute Cloud , and it provides scalable computing capacity. Using Amazon EC2 eliminates the need to invest in hardware, leading to faster development and deployment of applications. You can use Amazon EC2 to launch as many or as few virtual servers as needed, configure security and networking, and manage storage. It can scale up or down to handle changes in requirements, reducing the need to forecast traffic. EC2 provides virtual computing environments called “instances.”

The Azure Service Level Agreement (SLA) serves to ensure customer satisfaction by guaranteeing uptime for different Azure services. For your application to comply with these standards, it's crucial to understand what the agreement entails and how it influences your app's architecture.

Key Azure SLA Components

Types of SLAs

1. Monthly Uptime Percentage: Each service has an associated monthly uptime percentage, indicating the guaranteed uptime for that given month. It's calculated by dividing the total minutes in a month by the minutes of downtime. The result is represented as a percentage.

1. Service Credits: Azure offers service credits for underperformance, ensuring financial compensation if uptime isn't met.

Service Types

• Single SLA: All the services within a category have the same level of uptime guarantee. For instance, the "Core" category has a 99.99% uptime guarantee.

• Multiple SLA Tiers: Some services within a category offer different uptime guarantees. For example, within the "App Service" category, the services are divided into two tiers with different guarantee levels: Free and Shared has a 99.95% uptime guarantee, while Basic, Standard, and Premium have a 99.9% guarantee.

• No SLA: Some services don't have a defined SLA.

Application Design Considerations

Your application's design should align with the SLA guarantees to ensure high availability and performance.

S3 is short for Simple Storage Service, and Amazon S3 is the most supported storage platform available. S3 is object storage that can store and retrieve any amount of data from anywhere. Despite that versatility, it is practically unlimited as well as cost-effective because it is storage available on demand. In addition to these benefits, it offers unprecedented levels of durability and availability. Amazon S3 helps to manage data for cost optimization, access control, and compliance.

• Azure Monitor and Alerts: Set up criteria, like CPU or RAM usage, to trigger the scaling process.
• Time-Based Scaling: Adjust scale settings at specific times. For instance, increase capacity during business hours.

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