40+ [REAL-TIME] AWS EC2 Interview Questions and Answers

Last updated on 10th Apr 2024, Popular Course

One of the main AWS services, Amazon EC2, or Elastic Compute Cloud, enables scalable cloud computing. Without having to buy new hardware, users may easily scale computer capabilities up or down in response to demand. It facilitates the deployment of virtual servers, or instances, for various applications and workloads. EC2 offers a diverse range of instance types tailored to specific needs. Overall, EC2 enhances agility, reduces infrastructure costs, and fosters innovation in the digital realm.

1. What does AWS EC2’s EBS mean?

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For use with Amazon EC2 instances, persistent block storage volumes are offered via Amazon Elastic Block Store (EBS). Any operating instance inside the same availability zone can be connected to EBS, which has dependable and highly available storage volumes. They are automatically replicated inside their Availability Zone to shield them from component failure. Data persistence beyond the lifecycle of a single EC2 instance is made possible by the feature that allows EBS volumes to be stopped and resumed without causing data loss. Additionally, these volumes can be removed from one Instance and attached to another.

2. How are EC2 instances monitored?

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Amazon CloudWatch, a service that offers real-time monitoring of AWS resources and applications, can be used to monitor EC2 instances successfully. It gathers and tracks data, gathers and keeps an eye on log files, creates alarms, and responds automatically to modifications made to your AWS services. Metrics, including network traffic, disk read/write activity, and CPU utilization, can be tracked by CloudWatch for EC2 instances. Enabling comprehensive monitoring on EC2 instances makes data available in 1-minute intervals instead of the typical 5-minute interval, which is helpful for in-depth insights.

3. Explain Elastic IP (EIP) in AWS EC2.

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An Elastic IP address (EIP) is a static IPv4 address offered by AWS for dynamic cloud computing. EIPs can be associated with any running instance in a region and mask the failure of an instance or software by rapidly remapping the address to another instance in your account. Unlike traditional static IP addresses, EIPs allow you to mask instance or application failures by programmatically redirecting your network traffic to another instance. An EIP is free when associated with a running instance but incurs charges when disassociated, encouraging efficient use of resources.

4. What is the Difference between Elastic IP and Public IP in AWS EC2?

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	Feature	Elastic IP	Public IP
Type	Static IPv4 address	Dynamic IPv4 address (by default)
Persistence	Persistent until explicitly released	Dynamic, changes upon instance stop/start
Association	Can be associated/dissociated at any time	Automatically assigned at launch, released at termination
Control	Can be allocated to and retained by your AWS account	Assigned from a pool of available addresses, not reserved
Use Case	Suitable for scenarios requiring a fixed IP address	Suitable for temporary instances or applications with dynamic IP needs

5. What is EC2?

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A web service called Amazon Elastic Compute Cloud (EC2) offers scalable computing capability in the cloud. Its purpose is to simplify web-scale cloud computing for developers. The straightforward web service interface of EC2 makes it easy to obtain and configure capacity. You can operate on Amazon’s reliable computing environment and control your computer resources. By cutting the time it takes to procure and boot new server instances to minutes, EC2 enables you to scale capacity up and down quickly in response to changes in your computing needs.

6. What are Spot Instances, and how do they differ from On-Demand Instances?

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• The pricing for Spot Instances fluctuates based on supply and demand for EC2 capacity.
• Unlike On-Demand Instances, which provide fixed rates and guaranteed availability, Spot Instances can be interrupted by AWS with two minutes of notification when AWS needs the capacity back.
• Spot Instances is ideal for flexible, interruption-tolerant tasks such as batch processing, data analysis, or background tasks.

7.  Explain what an EC2 Dedicated Host is.

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Dedicated Hosts allow you to use your existing server-bound software licenses, like Windows Server, SQL Server, and SUSE Linux Enterprise Server (subject to your license terms), and can help you meet compliance requirements. Unlike standard EC2 instances that share the host machine with other customers, Dedicated Hosts ensure that your instances run on isolated hardware. They provide visibility and control over how instances are placed on the server, which can be essential for optimizing license costs, regulatory requirements, or performance.

8. Describe the lifecycle of an EC2 instance.

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The lifecycle of an EC2 instance begins when it is launched and ends when it is terminated. After launching, an instance goes through the pending state as it is prepared for use. Once ready, it enters the running state, where it is operational and can be accessed. Instances can be stopped and restarted, moving between the stopped and running states without data loss on EBS volumes. Modifications, such as changing the instance type, can be performed while it is stopped. Finally, terminating an instance permanently removes it and typically deletes any attached EBS volumes unless configured otherwise.

9. How can you improve the security of your EC2 instances?

Ans:

• Improving the security of EC2 instances involves several practices. 
• Firstly, Security Groups and Network Access Control Lists (ACLs) should be used effectively to control inbound and outbound traffic at the instance and subnet levels, respectively.
• Secondly, ensure only necessary ports are open and use SSH keys for Linux instances or RDP for Windows instances for secure access. 
• Implement IAM roles for EC2 instances to securely access AWS services without storing credentials on the Instance. 
• Regularly patch and update the operating system and applications.
• Additionally, use Amazon VPC to isolate your instances in a virtual network and enable VPC Flow Logs to see network traffic.

10. What is an Elastic Load Balancer (ELB), and how does it work with EC2?

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An Elastic Load Balancer automatically distributes incoming application traffic across multiple targets in numerous Availability Zones, such as EC2 instances, containers, and IP addresses. This improves the fault tolerance of the applications. ELB detects unhealthy instances and reroutes traffic to healthy instances until the unhealthy instances have been restored. It offers three types of load balancers that all feature high availability, automatic scaling, and robust security necessary to make your applications fault-tolerant. ELB integrates seamlessly with Amazon EC2, providing a fully managed load-balancing service.

11. What are Placement Groups in EC2, and what types are available?

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Placement Groups dictate how instances are placed on the underlying hardware to meet specific needs like low latency, high throughput, or spread out to reduce risks of simultaneous failures. There are three types of Placement Groups: Cluster, which places instances close together inside an Availability Zone to achieve low latency and high throughput; Spread, which places instances on distinct underlying hardware to reduce risks; and Partition, which spreads instances across partitions (each set of racks with its network and power source) within an AZ. Each type serves different use cases, from high-performance computing to fault-tolerant applications.

12. What are the instance types available in EC2?

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• AWS EC2 offers various instance types optimized to fit multiple use cases.
• Instance types comprise various combinations, giving flexibility in choosing the appropriate mix of resources for the applications. 
• Every category is designed to cater to particular workload requirements, from web servers and frontend fleets to memory-intensive applications and high-performance computing.

13. How can EC2 instances be categorized based on their use cases?

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• General Purpose: Balanced CPU, memory, and networking, suitable for web servers and developer environments.
• Compute Optimized: Higher CPU relative to memory, ideal for compute-bound applications like batch processing.
• Memory Optimized: Offers more memory relative to CPU, perfect for memory-intensive applications like databases.
• Storage Optimized: Designed for workloads that require high, sequential read and write access to large datasets on local storage.
• Accelerated Computing: Equipped with hardware accelerators or co-processors, such as GPU, suitable for graphics rendering and data analysis.

14. Explain Auto Scaling and how it benefits EC2 workloads.

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Auto Scaling ensures that the correct number of EC2 instances are available to handle the load for the application. It automatically adjusts the amount of computational resources based on the volume of user traffic or other specified conditions. This not only improves application availability and fault tolerance but also helps minimize costs by adding resources only when needed and terminating them when they’re not. Auto Scaling can be configured to maintain the health and performance of all instances in the group by performing health checks and replacing instances that are terminated or otherwise become unhealthy.

15. What are the benefits of using Amazon EC2 Reserved Instances?

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• Amazon EC2 Reserved Instances (RIs) provide a significant discount (up to 75%) compared to On-Demand instance pricing in exchange for a commitment to use the Instance for a one or three-year term.
• RIs can provide a capacity reservation, offering peace of mind that you can access EC2 compute capacity when needed. 
• They are best suited for applications with steady state or predictable usage and can lead to substantial cost savings over time.
• RIs can be purchased in three payment options – All upfront, Partial upfront, and No upfront – to meet various budgetary needs.

16. Describe the process for transferring an EC2 instance to a different region.

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Transferring an EC2 instance to a different region involves several steps. First, create an AMI for the example in the current region. This AMI is a snapshot of the Instance, including its configurations and data. Then, copy the AMI to the target region using the AWS Management Console, AWS CLI, or AWS API. Once the AMI is available in the target region, launch a new instance from this AMI in the desired region. Finally, if applicable, update any relevant configurations such as security groups, network settings, and Elastic IPs to reflect the change in region. This process is helpful for disaster recovery, geographic expansion, or optimizing latency for end-users.

17. How do you secure data at rest on EC2 instances?

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Securing data at rest on EC2 instances involves encrypting the data stored on the Instance’s EBS volumes. AWS provides EBS encryption using AWS Key Management Service (KMS) to manage the encryption keys. When you enable EBS encryption for a volume, data stored at rest, disk I/O, and snapshots created from the volume are all encrypted.The procedure is smooth. The user does not need to take any further action because encryption and decryption are done transparently. Using IAM policies to control access to the EC2 instances and EBS volumes is also essential, further enhancing security.

18. What mechanisms can achieve high availability and fault tolerance with EC2 instances?

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Achieving high availability and fault tolerance with EC2 instances involves:

• Deploying instances across multiple Availability Zones within a region.
• Using Elastic Load Balancing to distribute incoming traffic across these instances.
• Implementing Auto Scaling to adjust the number of cases dynamically based on demand.

Amazon Route 53 for DNS service can also help route users to the best-performing or closest region. Regularly backing up data using EBS snapshots and AMIs for recovery is also critical. Together, these mechanisms ensure that applications remain accessible and performant, even if one or more instances fail.

19. What is AWS Lambda, and how does it compare to EC2?

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The serverless compute solution offered by AWS Lambda automatically manages the underlying compute resources and executes code in response to events. Lambda is ideal for applications or back-end services that don’t need a persistent server.EC2, on the other hand, provides flexible, scalable virtual servers (instances) that allow you to run applications with more control over the computing environment. Lambda charges are based on the number of requests for your functions and the duration it takes for your code to execute, whereas EC2 charges are based on the compute instance types and the duration the instances are running.

20. Explain Instance Store Volumes and how they differ from EBS Volumes.

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Instance Store Volumes provide temporary block-level storage for EC2 instances. Instance Store Volumes offer high I/O performance and are ideal for frequently changing temporary data, such as buffers, caches, or scratch data. However, if an instance is stopped or terminated, the data on Instance Store Volumes is lost. In contrast, EBS Volumes are persistent storage that can be attached to EC2 instances. EBS data is preserved on instance stop or termination and can be detached and reattached to another instance, providing more flexibility and durability.

21. How can you reduce costs while using EC2 instances?

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To reduce costs with EC2 instances, consider the following strategies: Utilize Reserved Instances for workloads with predictable usage to benefit from lower pricing than On-Demand Instances. Employ Spot Instances for flexible, interruptible workloads to take advantage of lower prices. Optimize instance sizes based on performance monitoring to ensure you’re not over-provisioning. Use Auto Scaling to dynamically adjust the number and size of instances, ensuring you’re only paying for what you need. Lastly, turn off or terminate cases that are not in use to avoid unnecessary charges.

22. What are the key features of Amazon EC2 Auto Scaling?

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• It supports dynamic and scheduled scaling, enabling you to scale your application up or down based on demand or a fixed schedule.
• EC2 Auto Scaling can also be integrated with Elastic Load Balancing (ELB) to distribute traffic among instances within and across AZs, enhancing the fault tolerance of your application.
•  Additionally, it offers health check replacements for instances found to be unhealthy, ensuring that your application is always running on healthy cases.

23. Describe how you would migrate an on-premises application to AWS EC2.

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Migrating an on-premises application to AWS EC2 involves several steps: First, assess the application to understand its architecture, dependencies, and requirements. Next, decide on the migration strategy (rehosting, re-platforming, refactoring, etc.) based on the application’s needs and the desired outcomes. Prepare your AWS environment, including VPC setup and security configurations (security groups, IAM roles), and choose the appropriate EC2 instance type. Use AWS Migration Services like AWS Database Migration Service (DMS) or Server Migration Service (SMS) for data and server migration. Test the application in the AWS environment to ensure it functions correctly, then cut over from the on-premises setup to AWS. Finally, optimize your application for the cloud to take full advantage of AWS services and cost savings.

24. How do you ensure data integrity and security when transferring data to EC2 instances?

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• Ensuring data integrity and security during transfer to EC2 instances involves encrypting the data in transit and at rest. Use secure protocols such as SSH (Secure Shell) for file transfers (e.g., using SCP or SFTP) or HTTPS for web traffic to protect the data in transit.
• Additionally, AWS provides features like AWS Key Management Service (KMS) for managing encryption keys to encrypt your data at rest.
• Implementing network security measures such as VPCs, security groups, and NACLs to control access to your instances is crucial in safeguarding your data. Regularly audit and monitor the environment using tools like AWS CloudTrail and Amazon CloudWatch to promptly detect and respond to security threats.

25. What steps do you take to troubleshoot a connectivity issue to an EC2 instance?

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To troubleshoot connectivity issues to an EC2 instance, follow these steps: First, check the Instance’s security group rules to ensure they allow inbound traffic on the necessary ports from your IP address. Verify the network ACLs for the VPC and subnet to ensure they permit the inbound and outbound traffic. Ensure the Instance is running and check its system log for any errors that might indicate issues during startup. Confirm that the route table for the VPC correctly routes traffic to and from the internet for instances in a public subnet. If using a private subnet, ensure a NAT gateway or Instance is appropriately configured to allow outbound internet access.

26. How do you monitor EC2 instances, and what metrics are crucial?

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• To monitor EC2 instances, you can use Amazon CloudWatch, which provides detailed visibility into resource utilization, application performance, and operational health.
•  Key metrics to monitor include CPU Utilization to ensure the Instance is not over or under-utilized; Network In/Out to monitor the data traffic; Disk Read/Write Operations to check the I/O operations on the Instance; and Status Check Failed (Instance and System), to quickly identify any underlying problems with the Instance or the system it runs on.
• Setting up alarms in CloudWatch for these metrics can help proactively resolve issues and maintain the health and performance of EC2 instances.

27. What is Amazon EC2 Instance Connect, and how does it enhance security?

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Amazon EC2 Instance Connect provides a secure way to connect to your EC2 instances using SSH directly from the AWS Management Console or command line. It enhances security by offering a simple and temporary SSH access method, where you push your SSH public key to the instance metadata, and the key is automatically deleted after a short period (default is 60 minutes). This approach eliminates the need to manage SSH keys for each user and Instance, reducing the risk associated with long-term key storage and potential unauthorized access. EC2 Instance Connect also logs every connection attempt, providing an audit trail.

28. Describe how Elastic Beanstalk can be used with EC2 instances.

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• AWS Elastic Beanstalk is an orchestration service offered by Amazon Web Services for deploying applications which automate the deployment, provisioning, scaling, and monitoring of applications in the cloud.
• When using Elastic Beanstalk with EC2 instances, you upload your application code.
• Elastic Beanstalk automatically handles the deployment details of capacity provisioning, load balancing, auto-scaling, and application health monitoring. This integration allows the developers to focus on writing code rather than managing infrastructure.
• It supports platforms like Java, .NET, PHP, Node.js, Python, Ruby, Go, and Docker.

29. Explain how Amazon Machine Images (AMIs) are used with EC2.

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Amazon Machine Images (AMIs) are the templates for virtual servers (instances) in the Amazon EC2 environment. They contain all the information necessary to boot cases, including the operating system (OS), the application server, applications, and associated configuration settings. Users can launch instances using predefined AMIs provided by AWS, community AMIs, or create their own custom AMIs. This flexibility allows for easy scaling, as new cases can be quickly launched with identical configurations, ensuring consistency across your environment. Custom AMIs are particularly useful for speeding up the deployment of software, patches, or applications tailored to specific requirements.

30. How does Amazon EC2 use virtualization technology, and what types are available?

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Amazon EC2 uses virtualization technology to run instances and virtual servers in the AWS cloud. AWS primarily uses two types of virtualization: Paravirtualization (PV) and Hardware Virtual Machine (HVM). PV guests are aware they’re virtualized and can run on host hardware that does not have virtualization support in the CPU. However, HVM guests run as though they are on bare-metal hardware and can take advantage of hardware extensions that provide fast virtualization. AWS introduced the Nitro System, a combination of dedicated hardware and lightweight hypervisor, which further improves performance and security, allowing nearly all the compute and memory resources of the host hardware to be available to your instances.

31. What strategies would you use for disaster recovery of EC2 instances?

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• For disaster recovery (DR) of EC2 instances, you should implement a multi-faceted approach: Regularly back up data using Amazon EBS snapshots and automate the creation of Amazon Machine Images (AMIs) of your instances for quicker recovery. 
• Utilize AWS services like Amazon S3 for storing backups and Amazon Glacier for long-term archival. Design your architecture for high availability by deploying applications across multiple Availability Zones and, if necessary, across various regions. 
• Use AWS CloudFormation for infrastructure as code (IaC) to quickly replicate your environment. 
• Employ Amazon Route 53 for DNS failover to redirect traffic in case of an outage. Finally, regularly test your DR plan to ensure rapid recovery during a disaster.

32. Explain Elastic Network Interfaces (ENI) in the context of EC2.

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• The virtual network interface that can connect to an instance in a VPC is called an Elastic Network Interface (ENI). ENIs allow you to design a network architecture within the AWS cloud that resembles a traditional network you might operate in your data centre.
• Key features include having a primary private IP, one or more secondary private IPs, public IPs, an Elastic IP address (EIP), a MAC address, and the ability to attach and detach ENIs from instances. This flexibility supports several use cases,

33. How do Security Groups in EC2 work, and how do they differ from Network Access Control Lists (NACLs)?

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Security Groups in EC2 function as a virtual firewall for instances to regulate incoming and outgoing traffic at the instance level. Each security group has rules that filter traffic based on protocol, port, and source/destination IP addresses. Unlike NACLs, which operate at the subnet level, security groups are stateful; this means that if an incoming request is allowed, the response is automatically allowed, regardless of outbound rules. NACLs, on the other hand, are stateless, requiring both inbound and outbound rules to be explicitly set. Security groups offer instance-level security, while NACLs provide an additional layer of security at the subnet level.

34. Explain how you can automatically scale EC2 instances based on demand.

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You can automatically scale EC2 instances based on demand using Amazon EC2 Auto Scaling and AWS CloudWatch alarms. Auto Scaling allows you to define scaling policies that dynamically increase or decrease the number of cases based on metrics such as CPU utilization, network traffic, or custom metrics. You start by setting up an Auto Scaling group, specifying the minimum and maximum number of instances, and defining the desired capacity. Then, you create CloudWatch alarms to monitor the metrics you’ve chosen as indicators of demand. When a metric crosses a threshold, it triggers an alarm, initiating an Auto Scaling policy to adjust the number of instances. This ensures that you maintain optimal application performance and cost efficiency.

35. Describe the process and benefits of using Amazon EBS-optimized instances.

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• Amazon EBS-optimized instances provide dedicated bandwidth to Amazon EBS volumes, ensuring that neither the Instance’s other traffic nor the network traffic of some other cases impacts the communication between the Instance and its attached EBS volumes. 
• This optimization helps in achieving consistent performance for your I/O-intensive applications. When you launch an EBS-optimized instance, AWS provides a dedicated connection between the Instance and its EBS volumes, allowing for higher throughput and lower latency in EBS I/O operations.
• This feature is particularly beneficial for applications requiring sustained I/O performance, such as databases or transaction-heavy applications, ensuring they perform efficiently and predictably.

36. How does Amazon EC2 support high availability and fault tolerance?

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Amazon EC2 supports high availability and fault tolerance through multiple mechanisms: Availability Zones (AZs), Elastic IP addresses (EIPs), Amazon Elastic Load Balancer (ELB), and Auto Scaling. By deploying instances across multiple AZs within a region, you can protect your applications from the failure of a single data centre. EIPs can be quickly remapped from one Instance to another to handle instance failures. ELB distributes incoming traffic across instances in multiple AZs, increasing the fault tolerance of your applications. Auto Scaling ensures that you have the correct number of EC2 instances available to handle the load for your application, automatically launching new instances in an AZ if there are failures. Together, these features enable you to build resilient, fault-tolerant applications on the EC2 platform.

37. What are Spot Instances, and how can they benefit cost-saving strategies?

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• Spot Instances, instead of On-Demand pricing, can drastically reduce AWS computing costs by allowing bids on spare EC2 capacity and allowing such instances to operate as long as the bid exceeds the current Spot price.
• Utilizing Spot Instances is ideal for workloads that are flexible in when and how long they run, such as batch processing jobs, development and test environments, or any application that can handle interruptions gracefully.
• By incorporating Spot Instances into your cost-saving strategy, you can optimize your AWS costs without sacrificing the performance or availability of your applications, provided you manage the interruption aspect effectively.

38. What is the Difference between stopping and terminating an EC2 instance?

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• When you stop an EC2 instance, it performs a normal shutdown and transitions to a “stopped” state. 
• Stopping an instance means the Instance is not running; however, it’s still reserved for you, and you can start it again at any time.
• You won’t be charged for usage while it’s stopped, but you will continue to be arrested for any EBS volume storage attached to the Instance. 
• Terminating an EC2 instance, on the other hand, deletes it and any attached EBS volumes (unless the volume’s deleteOnTermination attribute is false). 
• Once terminated, the Instance cannot be started again. Ensuring that any necessary data is backed up before termination is essential.

39. How can you ensure that your EC2 instances comply with specific regulatory requirements?

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To ensure EC2 instances comply with specific regulatory requirements, you can use AWS services and features designed for compliance and security. AWS Identity and Access Management (IAM) allows you to control access to your EC2 instances. AWS Key Management Service (KMS) helps manage encryption keys for your data at rest. You can also use Amazon CloudWatch for monitoring and logging to ensure operational compliance. AWS Config makes assessing, auditing, and evaluating the configurations of AWS resources possible.

40. What are the implications of changing an instance type, and how is it done?

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• Changing an instance type (resizing) can adjust the compute, memory, and storage capacities to better meet your application’s demands, potentially improving performance or reducing costs. To change an instance type, the Instance must first be stopped.
• After stopping, you can change the instance type through the AWS Management Console, AWS CLI, or AWS API by selecting a new instance type compatible with your current Instance’s configuration (e.g., virtualization type, network type).
• Once changed, you can start the Instance again. It’s essential to consider factors such as the new Instance’s pricing, performance characteristics, and any potential compatibility issues with your application before changing.

41. Describe how to use AWS Lambda with EC2 for automation tasks.

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AWS Lambda can automate tasks for EC2 instances without requiring ongoing server management. For example, you can write Lambda functions to automatically start or stop EC2 instances based on a schedule, respond to instance state changes, or manage instance snapshots. This integration typically involves using Amazon CloudWatch Events to trigger Lambda functions based on specific events, such as EC2 instance state changes (e.g., an instance entering the “running” state). By leveraging Lambda, you can create a serverless architecture that automatically responds to changes in your environment, enhancing operational efficiency and potentially reducing costs by automating the scaling up and down of resources in response to demand.

42. What strategies can be used for cost optimization with EC2 instances?

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Cost optimization strategies for EC2 instances include choosing the suitable instance types, using Reserved Instances for long-term workloads, leveraging Spot Instances for flexible, cost-sensitive workloads, and monitoring with AWS CloudWatch to identify and shut down underutilized or idle resources. Auto Scaling can also help by adjusting the number of instances based on demand, ensuring you pay only for what you need. Additionally, using Amazon EC2 Savings Plans offers significant savings over On-Demand pricing in exchange for a commitment to a consistent amount of usage (measured in $/hour) for a one or 3-year term. Regularly reviewing and optimizing your instance sizes and types based on performance and cost can lead to substantial savings.

43. Describe Instance Metadata and its uses in AWS EC2.

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Data about an instance that can be used to configure or oversee the active Instance is known as instance metadata. It includes details such as the instance type, the IP address, the AMI used to launch the Instance, and more. This information can be accessed from within the Instance itself without using AWS credentials, making it highly useful for dynamic configuration of your instances without hard-coding values. For example, you can retrieve the Instance’s public IP address for your application configuration files or scripts. This data is beneficial for scripting and automation tasks in cloud-init scripts or when using AWS SDKs.

44. How do you manage traffic distribution to EC2 instances in different regions?

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• Managing traffic distribution to EC2 instances across different regions can be achieved using Amazon Route 53 and AWS Global Accelerator. Route 53 is a highly available and scalable cloud DNS web service that routes end-user requests to Internet applications hosted in AWS.
• It can perform health checks and route traffic to different AWS regions based on geographic location, latency, health, and other policies.
• AWS Global Accelerator improves the availability and performance of your applications with global traffic distribution to endpoints in multiple AWS regions. 
• It directs traffic to your application based on performance, routing it to the nearest healthy Instance based on geographic location and health. Both tools help achieve lower latency and higher transfer speeds, thus improving user experience.

45. What is Elastic Block Store (EBS), and how does it relate to EC2?

Ans:

Persistent block storage volumes are available from Amazon Elastic Block Store (EBS) for usage with Amazon EC2 instances. EBS volumes are network-attached and last for an example on their own. This implies that you can start a new instance and reconnect the volume because the data on EBS volumes is preserved even when an instance is shut down. EBS volumes can be used as primary storage for file systems, databases, or any other application that needs access to raw, unformatted, block-level storage and fine-grained updates. They also offer high availability and durability. They provide extensive storage options for EC2 instances and are simple to build, resize, snapshot, and encrypt. EBS volumes benefit applications that need to store important data and have quick access to persistent data.

46. What is the Difference between standard and Convertible Reserved Instances?

Ans:

• Standard Reserved Instances (RIs) provide a significant discount (up to 75%) compared to On-Demand instance pricing in exchange for committing to a specific instance type and usage (either 1 or 3 years) in a particular Availability Zone. 
• They are best suited for steady-state usage where the computing requirements are well-known and unlikely to change. Convertible Reserved Instances,on the other hand, offer a lower discount (up to 54%) but allow more flexibility. 
• They can be exchanged during their term for other Convertible Reserved Instances of equal or more excellent value, allowing changes to the instance family, operating system, tenancy, or payment option.
• This makes them suitable for users with changing requirements or those looking to leverage newer, more cost-effective instance types over time.

47. What are some everyday use cases for Amazon EC2 Spot Instances?

Ans:

When compared to On-Demand rates, Amazon EC2 Spot Instances offer substantial savings on underutilized EC2 capacity in the AWS cloud. Everyday use cases for Spot Instances include stateless, fault-tolerant, or flexible applications such as big data analytics workloads, containerized applications, high-performance computing (HPC), web servers, and development and testing environments. Spot Instances are ideal for workloads that can be interrupted or have flexible start and end times because if AWS needs the capacity back, Spot Instances can be terminated with short notice. By leveraging Spot Instances for appropriate workloads, users can significantly reduce the cost of running their applications in AWS.

48. How do you securely manage SSH access to EC2 instances?

Ans:

• Securing SSH access to EC2 instances involves several best practices. First, always use critical pairs for authentication instead of passwords, as keys are more secure and less susceptible to brute-force attacks. AWS generates vital pairs that you can utilize to connect to your instances securely.
• Second, Security Groups should be configured to restrict SSH access (typically port 22) only from known IP addresses, reducing the surface area for attacks.
• Third, AWS Identity and Access Management (IAM) roles can be used to control who can launch instances with specific key pairs.
• Fourth, regularly rotate and manage SSH keys to ensure only authorized users can access them. Additionally, consider using bastion hosts as a secure, single entry point for accessing your EC2 instances, further isolating them from direct internet access.
• Implementing these measures helps ensure that SSH access to your instances is tightly controlled and secured against unauthorized access.

49. What is the Amazon EC2 hibernation feature, and what are its benefits?

Ans:

Amazon EC2 hibernation allows you to pause and resume your instances later from the saved state, preserving the Instance’s RAM contents to the root EBS volume. This feature benefits long-running processes or applications that take a long time to initialize. By hibernating instead of stopping or terminating an instance, you can quickly resume work without reloading data into memory or restarting the application, saving time and computational resources. Hibernation also helps save costs for workloads that do not need to run 24/7 by avoiding charges for instances when they are paused. However, it’s essential to note that EC2 instance hibernation is only supported for instances with EBS-backed volumes and certain instance types and sizes.

50. What are Amazon EC2 Auto Scaling Warm Pools, and how do they benefit application scaling?

Ans:

• Amazon EC2 Auto Scaling Warm Pools enable you to improve the responsiveness and efficiency of your applications by reducing the time it takes to scale out EC2 instances. By maintaining a pool of pre-initialized cases in a “warmed-up” state, Warm Pools allow you to quickly increase capacity in response to demand spikes without waiting for new instances to launch and initialize.
• This mainly benefits applications with significant startup times due to initial load, configuration, or complex initialization sequences. Warm Pools not only enhance the user experience by providing faster scaling response times but also help manage costs by allowing instances in the Warm Pool to be stopped (not terminated), thereby incurring lower costs than running cases. This feature is essential for balancing performance and cost efficiency in dynamic environments.

51. Explain the EC2 Fleet and how it optimizes the procurement of computing resources.

Ans:

Amazon EC2 Fleet simplifies the provisioning of EC2 resources by allowing you to manage thousands of instances with a single API call. EC2 Fleet enables you to specify the capacity requirements, instance types, and pricing options across Spot, On-Demand, and Reserved Instances. This flexibility allows EC2 Fleet to automatically launch the optimal combination of instances based on your specifications, balancing cost and performance objectives. The key benefit of EC2 Fleet is its ability to aggregate capacity across different instance types and purchase options, optimizing your compute resources to get the best possible cost while meeting your capacity requirements. It’s beneficial for batch processing, data analysis, and image rendering workloads, where the price can be significantly reduced without compromising performance.

52. How does AWS EC2 handle instance metadata and user data, and their common uses?

Ans:

Instance metadata and user data pass information into your EC2 instances. AWS provides a unique URL that instances can access to retrieve metadata information, such as the instance ID, public IP, and security groups. User data is scripts or data supplied to the Instance upon Launch, which can be used to run scripts after the Instance starts up or to carry out automated configuration chores. Typical uses of user data include installing software, updating the AWS CLI, or configuring network settings. Both metadata and user data are accessible from within the Instance, providing a flexible and powerful way to automate and configure instances without manual intervention.

53. Discuss the implications of changing an EC2 instance type and how it can be done.

Ans:

• Changing an EC2 instance type involves modifying the Instance to a different size or family to adjust to changing workload requirements, such as needing more CPU, memory, or network capacity. This process can help optimize costs, improve performance, or both.
• To change an instance type, the instance type must be stopped, the instance type changed, and then the Instance restarted. It’s essential to consider compatibility (e.g., virtualization type and network adapter compatibility), as not all instance types are compatible with each workload or AMI. Additionally, understand the billing implications, especially if moving from a reserved instance or using Spot Instances.
• Changing instance types provides flexibility in managing and optimizing AWS resources, allowing applications to scale or adapt to new requirements efficiently.

54. What strategies can be employed to reduce costs associated with EC2 instances?

Ans:

• To reduce costs associated with EC2 instances, several strategies can be employed:
• Utilize Reserved Instances for workloads with predictable usage to benefit from significant discounts over On-Demand pricing.
• Leverage Spot Instances for flexible, fault-tolerant applications to take advantage of lower prices.
• Use Auto Scaling to dynamically adjust the number of instances, ensuring you only pay for what you need.
• Optimize instance sizes based on performance monitoring to ensure you’re not over-provisioning.
• Consider using newer, more efficient instance types which offer better price/performance ratios.
• Please turn off or terminate instances when not in use, especially in development and testing environments.

55. How does AWS ensure the high availability and fault tolerance of EC2 instances?

Ans:

AWS ensures the high availability and fault tolerance of EC2 instances through multiple mechanisms:

• Availability Zones (AZs): AWS can deploy instances across multiple AZs within regions. Each AZ is a separate physical location with power, cooling, and networking, designed to be insulated from failures in other AZs.
• Elastic Load Balancing (ELB): ELB automatically distributes incoming application traffic across multiple instances in multiple AZs, increasing the fault tolerance of your applications.
• Auto Scaling: This feature automatically adjusts the number of instances in response to changing demand, ensuring the application can handle the load even if a few cases fail.
• Amazon EBS Snapshots: By creating snapshots of your EBS volumes, you can quickly recover your data in another AZ or region in case of failure.
• Amazon EC2 Instance Store Backup: Regularly backing up data to Amazon S3 or EBS for instances that use instance store volumes can protect against data loss.

56. What is the Difference between vertical and horizontal scaling in AWS EC2?

Ans:

Vertical scaling (scaling up/down) involves changing the instance size within the same instance family or to a different family. It’s effectively changing an existing instance’s compute, memory, and storage capacities to meet the workload’s demands. This can be quickly done by stopping the Instance, changing its type, and starting it again. On the other hand, horizontal scaling (scaling out/in) involves increasing or decreasing the number of instances in your application to handle the load. This is typically managed by AWS Auto Scaling, which adjusts the number of EC2 instances dynamically based on defined policies and conditions, such as CPU usage or network traffic. Horizontal scaling offers high availability and fault tolerance by distributing loads across multiple instances. In contrast, vertical scaling provides a straightforward way to increase the power of a single instance for workloads that aren’t easily distributed.

57. Discuss the significance of instance types in AWS EC2.

Ans:

Instance types in AWS EC2 categorize the virtual servers by capacity, including CPU, memory, storage, and networking capacity combinations. Choosing the right instance type is crucial for optimizing the performance and cost-effectiveness of applications running on EC2. AWS offers a wide range of instance types designed to meet various use cases, from general-purpose instances suitable for web servers and development environments to compute-optimized, memory-optimized, and storage-optimized instances tailored for compute-intensive applications, high-performance databases, and workloads requiring high sequential read and write access, respectively. Understanding the specific needs of your application—such as compute power, memory, storage I/O, and network performance—allows you to select the most appropriate instance type, ensuring efficient resource utilization and cost optimization.

58. How does AWS EC2 integrate with other AWS services?

Ans:

AWS EC2 integrates seamlessly with a wide range of AWS services, enhancing functionality and providing comprehensive solutions for deploying, managing, and optimizing applications in the cloud. Key integrations include:

• Amazon EBS: Provides block storage volumes for persistent data storage with EC2 instances.
• Amazon S3: Offers scalable object storage for data backup, archival, and analytics.
• Amazon RDS: Facilitates easy setup, operation, and scaling of relational databases in the cloud, which can be accessed from EC2 instances.
• AWS Elastic Load Balancing (ELB): Automatically distributes incoming application traffic across multiple EC2 instances to balance load and enhance application availability and scalability.

59. Describe the process of launching an EC2 instance from an AMI.

Ans:

Launching an EC2 instance from an Amazon Machine Image (AMI) involves several steps. First, choose an AMI that serves as the template for the Instance, containing the operating system and any pre-installed software. Next, select an instance type that matches your desired balance of computing, memory, and networking resources. Configure instance details like the network and subnet, and add storage if the default EBS volume size or type doesn’t meet your needs. Configure a security group to define the rules for inbound and outbound traffic to your Instance.

60. What is EC2 Instance?

Ans:

An EC2 Instance is the virtual server in Amazon’s Elastic Compute Cloud (EC2) for running applications on the Amazon Web Services (AWS) infrastructure. It’s essentially a virtual computer that can run applications, services, and processes like you would on a physical computer. Instances come in different types, offering various combinations of CPU, memory, storage, and networking capacity to meet the needs of particular applications.

61. What is Amazon Lightsail?

Ans:

• Amazon Lightsail is a cloud platform offering from AWS designed to make it simpler for users to launch and manage virtual private servers (VPS) with just a few clicks.
• Lightsail provides a simplified interface for deploying applications, websites, or development environments on preconfigured instances with a set monthly price.
• It comes with all the essentials for getting a project off the ground, including a low-cost, predictable virtual machine, SSD-based storage, data transfer, DNS management, and a static IP.

62. Describe the process of launching an auto-scaled application on EC2. What are the steps involved in ensuring it scales properly?

Ans:

• To launch an auto-scaled application on AWS EC2, you define a launch template or configuration specifying the EC2 instance type, AMI, and other configuration details such as key pairs, security groups, and attached block storage. 
• Next, you create an Auto Scaling group that references this template and defines parameters such as the minimum and maximum number of instances, desired capacity, and availability zones for deployment. 
• You then define scaling policies based on performance metrics such as CPU utilization or network traffic, which trigger scaling actions to adjust the capacity dynamically. These policies ensure that the application scales up to maintain performance during high demand and scales down to reduce costs when demand decreases. 
• It’s crucial to monitor the application’s performance using AWS CloudWatch to tweak scaling policies and ensure they align with actual application needs and performance goals.

63. What are AWS Outposts?

Ans:

For a consistent hybrid experience, AWS Outposts is a fully managed service that extends AWS infrastructure, AWS services, APIs, and tools to almost any data centre, co-location space, or on-premises facility. It is intended for usage in scenarios where users wish to run workloads on AWS infrastructure but are compelled to maintain them on-site because of local data processing requirements or latency constraints. Outposts enable almost any data centre, co-location space, or on-premises facility to utilize native AWS services, infrastructure, and operational models. The same AWS Management Console, APIs, and CLI may be used to manage users’ AWS resources on-premises and in the cloud.

64. What is the administration of configuration? Why would I want to utilize it for resource provisioning in the cloud?

Ans:

• Systems administration and online operations have traditionally used configuration management. However, its cultural appeal has been restricted. Since version control was not implemented in software development, most systems administrators manually set up servers.
• Then, each server may vary significantly, as they typically do. However, troubleshooting is simple because you can log in to the box and perform direct operations. With configuration management, servers are managed like puppet strings using a powerful automation tool.
• The fact that all configurations are versioned and monitored forces standardization, best practices, and reproducibility.

65. Describe the Amazon Web Services concept to replicate perimeter security.

Ans:

Amazon EC2 does not offer traditional perimeter security, which we are already accustomed to utilizing firewalls and other devices. AWS supports security groups. SSH access can create a jump box’s security group with only port 22 open. A database group and web server group are then formed from there. The jump box group’s port 22 is only allowed to reach the webserver group, but ports 80 and 443 are open to all users. Additionally, the database group permits port 22 from the jump box group and port 3306 from the webserver group. Any machine can access the database if added to the webserver group.

66. Describe setting up a scalable and secure web application architecture using EC2.

Ans:

• Setting up a scalable and secure web application on EC2 involves leveraging several AWS services and best practices. Start by deploying your application across multiple EC2 instances in different Availability Zones within an Amazon VPC for high availability.
• Use Elastic Load Balancing (ELB) to distribute incoming traffic across these instances, enhancing scalability and fault tolerance.
• Implement Auto Scaling to automatically adjust the number of EC2 instances in response to traffic fluctuations, ensuring that you maintain performance while controlling costs.

67. How do we use AWS Systems Manager with EC2 for system operations and maintenance?

Ans:

AWS Systems Manager simplifies system operations and maintenance by providing tools for efficiently managing EC2 instances and other AWS resources. Allowing you to automate operational duties contributes to the upkeep of system security and compliance. You can organize your resources with Systems Manager to facilitate group management. Without logging into each EC2 instance individually, you can use Run Command to remotely carry out administrative activities at scale across all the cases. Patch Manager streamlines the process of applying security and non-security updates to the manager.

68. How do you control network traffic for EC2 instances within a VPC?

Ans:

Managing network traffic for EC2 instances within a Virtual Private Cloud (VPC) involves leveraging several AWS features to ensure security and efficiency. Security Groups act as a virtual firewall for instances to control inbound and outbound traffic at the instance level, specifying allowable protocols, ports, and source/destination IP ranges. Network Access Control Lists (ACLs) provide a layer of security at the subnet level, offering stateless filtering of traffic entering and leaving each subnet.

69. How do you leverage AWS Lambda with EC2 for event-driven scaling?

Ans:

• Integrating AWS Lambda with EC2 allows for sophisticated, event-driven scaling solutions that are responsive to your application’s demands. You can use CloudWatch Events or EventBridge to trigger a Lambda function based on specific criteria, such as CPU utilization thresholds or network activity.
• The Lambda function can then programmatically adjust the capacity of your EC2 instances, either by interacting directly with the EC2 API to launch or terminate instances or by modifying Auto Scaling Group parameters to handle the scaling logic.

70. Discuss strategies for encrypting data on EC2 instances and their benefits.

Ans:

Encrypting data on EC2 instances involves protecting data at rest and in transit to ensure confidentiality and compliance with regulatory requirements. AWS provides EBS encryption for data at rest using AWS Key Management Service (KMS) to manage keys. When you create an EBS volume, you can opt to encrypt it, and any data written to the volume will be automatically encrypted before being written to the disk. You can use tools like BitLocker (for Windows) or dm-crypt (for Linux) for the operating system and application-level encryption. For data in transit, implement SSL/TLS encryption for your applications or use VPN connections for secure data transfer between your EC2 instances and external systems.

71. What are the best practices for securing EC2 instances?

Ans:

• Securing EC2 instances involves a multi-layered approach encompassing AWS-provided capabilities and general security best practices.
• Firstly, always use Security Groups to control inbound and outbound traffic to your instances, ensuring that only necessary ports and IP ranges are allowed.
• Implement the principle of least privilege by using IAM roles for EC2, granting only the permissions necessary for the tasks the Instance needs to perform. Regularly patch and update the operating system and applications running on your instances to mitigate vulnerabilities.
• Utilize Amazon VPC to isolate your instances in a private network, and consider using Network Access Control Lists (NACLs) for an additional layer of security.

72. What is AWS S3?

Ans:

An object storage service called Amazon Simple Storage Service (Amazon S3) provides performance, security, scalability, and data availability that are among the best in the business.Any file can be kept on the cloud object storage service Amazon S3.Thus, you may save and retrieve any information on the Amazon S3 cloud. You can also open these files to the world or just your company.

73. How do I start an instance of EC2?

Ans:

• Open the EC2 console after logging into your AWS console.
• From the dashboard, select Launch Instance.
• Select an AMI.
• Decide on an instance kind.(Predicted on RAM and OS)
• Choose Review and Launch, letting the wizard handle the last few configuration options.
• On the Review Instance Launch screen, select Security Groups from the Security Groups          list, then click Launch.
• Select an Existing key pair when it asks for one.
• To access the EC2 console once more, click View Instance.

74. How is an EC2 instance upgraded?

Ans:

The procedures listed below can be used to update EC2 (with a few minutes of downtime):

•  Open the AWS EC2 Console and log in.
•  From the left pane, navigate to “Instances” and choose the Instance you wish to update.
•  Click on the Instance and choose “Stop Instance” from the menu. This will quickly end the Instance since we cannot update it while running.
•  After stopping the Instance, pick “Instance Settings” and “Change Instance Type” with a right-click.
•  Select the new instance type on the Instance Selection screen. Since I’m upgrading from “t2.Micro” to “t2.medium,” I’ll choose “t2.medium” and click “Apply.”
•  To start the Instance, right-click it again and choose “Start Instance”.

75. How can you upgrade the EC2 Instance without downtime?

Ans:

• Create an image of your Current Instance; you can do this by right-clicking on your Instance and then selecting “Image” -> “Create Image” (Creates an AMI of the Instance)
• Now create a new EC2 Instance with upgraded configuration and use above created image
• Deasccociate Public IP Address from the old server and associate it with the new EC2 Server
• That’s it; your new upgraded Ec2 instance is ready.
• You can terminate the old Instance after checking that the new one has all your data.

76. How Would You Stop the Deletion of Root Device Volume Using a Console?

Ans:

Select Launch Instance from the EC2 console.

• Select the AMI and an instance type from the Amazon Machine Image page.
• Adjust the settings on the Instance Details pages.
• On the Add Storage page, uncheck the “Delete on Termination” option.
• After finishing the last few wizard configuration pages, click Launch.

77. Describe the Elastic Transcoder.

Ans:

We must change the video’s resolution and format to accommodate a wide range of devices with varied resolutions, including laptops, tablets, and smartphones. This process can be easily completed with the help of a cloud-based media transcoding technology called Elastic Transcoder, an AWS Service product. It is affordable, easy to use, and expandable for developers and businesses.

78. What are the various Amazon EC2 instance pricing models?

Ans:

• On-Demand Instances: Pay only for the instances you use, with no long-term obligations.
• Savings Plans: You promise to use the money consistently for one or three years.
• Reserved Instances: For one or three years, you commit to a particular configuration,                                          instance type, and region.
• Spot Instances: Utilize idle EC2 instances to cut expenses dramatically.

79. What are Solaris and AIX operating systems? Are they available with AWS?

Ans:

Sun Microsystems created the Unix operating system known as Solaris, renowned for its scalability, security features, and compatibility with x86 and SPARC architectures.AIX (Advanced Interactive eXecutive) is a Unix operating system developed by IBM, designed for enterprise-level scalability, reliability, and security, primarily running on IBM Power Systems. As of my last update, AWS does not natively support Solaris or AIX operating systems for EC2 instances due to the specific hardware requirements and licensing models of these platforms

80. How do you configure CloudWatch to recover an EC2 instance?

Ans:

To configure AWS CloudWatch to recover an EC2 instance automatically, you would create a CloudWatch alarm that monitors a specific metric (such as CPU utilization) or status check (such as system status check failure) for the Instance. Here’s a brief process: In the CloudWatch console, create a new alarm, select the EC2 instance and the metric or status check to monitor. Set the threshold that triggers the alarm, then specify the action as “Recover this instance” for the alarm action. Configure notification details to alert you when the alarm state changes.

81. What are Key-Pairs in AWS?

Ans:

Key-Pairs, which comprise a public key and a private key, are a component of AWS’s security measures for EC2 instances. An EC2 instance can have a crucial pair specified when it is launched. While the private key stays with the user, the public key is kept on the Instance to enable safe SSH access. You decrypt the login credentials with the private key to establish a connection to your Instance. Amazon generates the critical pair without keeping the private key on file to guarantee that only the user who generated the key pair can start a secure SSH connection to the Instance.

82. Describe SnowBall.

Ans:

Using a small application called SnowBall, terabytes of data are transferred inside and outside the AWS environment.

The following methods are available for sending data with SnowBall:

• A decision is made.
• There is a link to the SnowBall app.
• A copy of the information is given to the SnowBall program.
• After that, data is moved to Amazon S3.

83. Which Storage Classes are offered by Amazon S3?

Ans:

• The class of storage Instant Glacier Retrieval on Amazon S3
• Amazon S3 Glacier Flexible Retrieval Storage
• S3 Outposts storage class;
• Amazon S3 Glacier Deep Archive
• Amazon S3 Standard
• Amazon S3 Reduced Redundancy Storage;
• Amazon S3 Standard-Infrequent Access
• Amazon S3 One Zone-Infrequent Access
• S3 Intelligent-Tiering on Amazon .

84. What is the purpose of using Amazon Virtual Private Cloud (VPC), and what is it?

Ans:

A virtual private cloud (VPC) is the best option for connecting your data centre to cloud resources. Every Instance in the VPC you host is given a private IP address that can be accessible from your data centre once you link your data centre to it. In this manner, you can use the resources in your public cloud as though they were on your network.

85. Describe the Draining of Connections

Ans:

With the help of an AWS tool called Connection Draining, we may fulfill pending requests on servers being updated or retired.We allow the Load Balancer to have an outgoing instance fulfil its current requests for a while before forwarding any new requests by turning on this Connection Draining. If Connection Draining is not enabled, a departing instance will go off instantly, and all pending requests will fail.

86. In AWS, what is Power User Access?

Ans:

An Administrator User is the same as the owner of AWS resources. In addition to creating, editing, deleting, and inspecting resources, the Administrator User can provide access to other AWS users. A Power User is given Administrator Access without the ability to manage users and permissions. Although they cannot grant other users permissions, Power User Access users can edit, delete, view, and add resources.

87. What components make up a template for AWS CloudFormation?

Ans:

• Output values
• Parameters for the template
• Tables of data
• Materials
• Version of the file format

88. How can EC2 backup be automated with EBS?

Ans:

• To list the Amazon EBS volumes that are locally associated with the Instance, retrieve the list of instances and establish a connection with AWS using the API.
• List every volume’s snapshots and give each one a retention period. Make a snapshot of every disk later on.
• If the snapshot is over the retention term, delete it.

89. What distinguishes Instance Store from EBS?

Ans:

EBS is a type of long-term storage that allows for future data restoration. Conversely, an instance store is a type of temporary storage that is physically affixed to a host computer. One Instance cannot be detached and attached to another using an instance store. Data in an instance store is lost if any instance is stopped or terminated, unlike with EBS.

90. Is it possible to make an EFS or EBS backup, and if so, how?

Ans:

•  Log in to the Amazon Management Console by opening it.
•  Click the “launch EFS-to-EFS-restore” button.
•  Use the console navigation bar’s region selector to select a region.
•  Verify that you have chosen a suitable template by visiting the Choose Template page.
•  Give the stack of solutions a name.
•  Review the template’s specifications and make any required changes.