Cloud computing has become the major driving force for the growth of businesses of all sizes now. The worldwide cloud market in Q3 2020 grew by 33% as compared to Q3 2019, along with expenditure in the cloud segment. In such a scenario, AWS has emerged as the most popular cloud service, and given the huge skill gaps in the industry, there has been a huge demand for AWS certified cloud architects and professionals. If you are willing to start a career in cloud computing then you have landed on the right page. We have curated some of the most popular AWS Interview questions and answers to help you crack your AWS interview.
Top AWS Interview Questions & Answers
Q1. What is AWS?
Ans. It is among the most commonly asked AWS interview questions. There is little room to be creative – you either know or you don’t know the answer.
Amazon Web Services or AWS is a set of cloud computing services and tools from Amazon. It offers over 200 comprehensive data center services globally. AWS is a cross-functional platform that offers a wide variety of services ranging from data warehousing to content delivery.
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Q2. What is Amazon S3?
Ans. Amazon S3 (Simple Storage Service) is object storage with a simple web service interface to store and retrieve any amount of data from anywhere on the web.
To learn more about AWS, read our blog on – What is AWS?
Q3. What is AWS SNS?
Ans. Amazon Simple Notification Service (Amazon SNS) is a push notification service used in sending individual messages to a big group of mobile or email subscriber systems including Amazon SQS queues, AWS Lambda functions, and HTTPS endpoints. It is both application-to-application (A2A) and application-to-person (A2P) communication.
Q4. What is CloudFront?
Ans. Amazon CloudFront has become one of the most popular delivery networks (content delivery network, CDN) in the world, thanks to its ability to accelerate the transmission of static and dynamic web content, as .html, .css, and .js files. CloudFront works efficiently with services like AWS Shield and helps in curbing DDoS attacks. It utilizes Amazon S3, Elastic Load Balancing, or Amazon EC2 as sources for your applications and uses Lambda @ Edge to run custom code closer to and personalize customer users.
Q5. What are the main differences between ‘horizontal’ and ‘vertical’ scales?
Ans. The main differences between ‘horizontal’ and ‘vertical’ scales are –
Provides new resources along with new hardware devices to support the infrastructure
You would need to increase power resources by upgrading the current machine
Used in distributed systems
Used in virtualization
Resilient to system failure
Single point of failure
Utilizes network calls
Increases the capacity of existing hardware or software by adding additional resources
Connects multiple system entities, both hardware, and software such that they work as a single logical unit
Difficult to implement
Easy to implement
Q6. What is Sharding?
Ans. Sharding or horizontal partitioning is a scale-out technique for relational databases. This technique is used to put that data into smaller subsets and distribute them across physically separated database servers, where every server is called a database shard. These database shards have the same hardware, database engine, and data structure so that a similar level of performance is generated.
Image – Sharded database architecture (Source)
Q7. What are the different types of load balancers in EC2?
Ans: There are three types of load balancers in EC2 –
Application Load Balancer – These balancers are designed to make routing decisions at the application layer.
Network Load Balancer: Network load balancer handles millions of requests per second and helps in making routing decisions at the transport layer.
Classic Load Balancer: Classic Load Balancer is mainly used for applications built within the EC2-Classic network. It offers basic load balancing at varying Amazon EC2 instances.
Q8. What is DynamoDB?
Ans. DynamoDB is a NoSQL database. It is very flexible and performs quite reliably – and can be integrated with AWS! It offers fast and predictable performance with seamless scalability. With the help of DynamoDB, you do not need to worry about hardware provisioning, setup, and configuration, replication, software patching, or cluster scaling.
Q9. What is AWS CloudFormation?
Ans. AWS CloudFormation, is an Amazon service, dedicated to solving the need to standardize and replicate the architectures to facilitate their execution and optimize resources and costs in the delivery of applications, or compliance with the requirements of the organization. CloudFormation allows creating a proprietary library of instance templates or architectures capable of being delivered at any time and in an organized manner, through programming.
Q10. What are the advantages of using AWS CloudFormation?
Ans. It is one of the most popular AWS interview questions.
AWS CloudFormation –
- Reduces infrastructure deployment time
- Reduces environment repair time
- Increases confidence in deployments
- Replicates complex environments, for example, have complex environments for development, pre-production and production, that are the same, or almost the same, simply by scaling up resources
- Reuses the definitions between different products
Q11. What is Elastic Beanstalk?
Ans. Elastic Beanstalk is an orchestration service by AWS, used in various AWS applications such as EC2, S3, Simple Notification Service, CloudWatch, autoscaling, and Elastic Load Balancers. It is the fastest and simplest way to deploy your application on AWS using either AWS Management Console, a Git repository, or an integrated development environment (IDE).
Q12. What is Geo Restriction in CloudFront?
Ans. Geo restriction, also known as geoblocking, is used to prevent users in specific geographic locations from accessing content that you’re distributing through a CloudFront web distribution.
Q13. What is a T2 instance?
Ans. T2 instances are designed to provide moderate baseline performance and the capability to burst to higher performance as required by workload.
Q14. What is AWS Lambda?
Ans. AWS Lambda is a compute service that lets you run code in the AWS Cloud without provisioning or managing servers.
Q15. What is a Serverless application in AWS?
Ans. The AWS Serverless Application Model (AWS SAM) extends AWS CloudFormation to provide a simplified way of defining the Amazon API Gateway APIs, AWS Lambda functions, and Amazon DynamoDB tables needed by your serverless application.
Q16. What is the use of Amazon ElastiCache?
Ans. Amazon ElastiCache is a web service that makes it easy to deploy, operate, and scale an in-memory data store or cache in the cloud.
Q17. Explain how the buffer is used in Amazon web services.
Ans. The buffer is used to make the system more robust to manage traffic or load by synchronizing different components.
Q18. Differentiate between stopping and terminating an instance.
Ans. When an instance is stopped, the instance performs a normal shutdown and then transitions to a stopped state.
When an instance is terminated, the instance performs a normal shutdown, then the attached Amazon EBS volumes are deleted unless the volume’s deleteOnTermination attribute is set to false.
Also Read>> Top 10 Reasons to learn AWS
Q19. Is it possible to change the private IP addresses of an EC2 while it is running/stopped in a VPC?
Ans. The primary private IP address cannot be changed. Secondary private addresses can be unassigned, assigned, or moved between interfaces or instances at any point.
Q20. Give one instance where you would prefer Provisioned IOPS over Standard RDS storage?
Ans. Provisioned IOPS can be preferred over Standard RDS storage when we have batch-oriented workloads.
Q21. What are the different types of cloud services?
Ans. Different types of cloud services are:
- Software as a Service (SaaS)
- Data as a Service (DaaS)
- Platform as a Service (PaaS)
- Infrastructure as a Service (IaaS)
Q22. What is the boot time for an instance store-backed instance?
Ans. The boot time for an Amazon Instance Store -Backed AMI is less than 5 minutes.
Q23. Will you use encryption for S3?
Ans. Yes, I will, as it is a proprietary technology. It’s always a good idea to consider encryption for sensitive data on S3.
Q24. What is Identity Access Management and how is it used?
Ans. It is a web service, which is used to securely control access to AWS services. Identity Access Management allows you to manage users, security credentials, and resource permissions.
Q25. Explain the advantages of AWS’s Disaster Recovery (DR) solution.
Ans. This is also among the most popular AWS interview questions asked in an AWS interview.
Following are the advantages of AWS’s Disaster Recovery (DR) solution:
- AWS offers a cost-effective backup, storage, and DR solution, helping the companies to reduce their capital expenses
- Fast setup time and greater productivity gains
- AWS helps companies to scale up even during seasonal fluctuations
- It seamlessly replicates on-premises data to the cloud
- Ensures fast retrieval of files
Q26. How do you send requests to Amazon S3?
Ans. We can achieve this by using the REST API or the AWS SDK wrapper libraries. These elements wrap the underlying Amazon S3 REST API.
Q27. What is DynamoDB?
Ans. DynamoDB is a fully managed proprietary NoSQL database service, supporting key-value and document data structures. It can be used when a fast and flexible NoSQL database with a flexible data model and reliable performance is required.
Q28. What is Redshift?
Ans. Redshift is a petabyte size data warehouse service by Amazon. It is easy, cost-effective, and scalable, and can be fully configured to analyze your entire data with the existing business intelligence tools.
Q29. Which data centers are deployed for cloud computing?
Ans. There are two data centers in cloud computing, one is Containerized Data centers, and another is Low-Density Data Centers.
Q30. Which AWS services will you use to collect and process e-commerce data for near real-time analysis?
Ans. Following are the AWS services that will be used to collect and process e-commerce data for near real-time analysis:
- Amazon DynamoDB
- Amazon ElastiCache
- Amazon Elastic MapReduce
- Amazon Redshift
Q31. What is SQS?
Ans. Simple Queue Service (SQS) is a distributed message queuing service that acts as a mediator for two controllers. It is a pay-per-use web service.
Q32. What are the popular DevOps tools?
Ans. The popular DevOps tools are –
- Chef, Puppet, Ansible, and SaltStack – Deployment and Configuration Management Tools
- Docker – Containerization Tool
- Git – Version Control System Tool
- Jenkins – Continuous Integration Tool
- Nagios – Continuous Monitoring Tool
- Selenium – Continuous Testing Tool
Q33. What is Hybrid cloud architecture?
Ans. It is a type of architecture where the workload is divided into two halves among which one is on public load and the other is on the local storage. It is a mix of on-premises, private cloud and third-party, and public cloud services between two platforms.
Q34. What Is Configuration Management?
Ans. Configuration management is used to manage the configuration of systems and the services that they provide entirely through code. This is a repetitive and consistent process that is achieved through –
- Intuitive command-line interface
- A lightweight and easily readable domain-specific language (DSL)
- Comprehensive REST-based API
Q35. What are the features of Amazon cloud search?
Ans. Amazon cloud search features:
- AutoComplete advice
- Boolean Searches
- Entire text search
- Faceting term boosting
- Prefix Searches
- Range searches
Q36. How do you access the data on EBS in AWS?
Ans. Data cannot be accessible on EBS directly by a graphical interface in AWS. This process includes assigning the EBS volume to an EC2 instance. Here, when the volume is connected to any of the instances either it can be Windows or Unix, you can write or read on it. First, you can take a screenshot from the volumes with data and build unique volumes with the help of screenshots. Here, each EBS volume can be attached to only a single instance.
Q37. What is the difference between Amazon RDS, Redshift, and Dynamo DB?
Ans. Differentiate between Amazon RDS, Redshift, and Dynamo DB:
|Features||Amazon RDS||Redshift||Dynamo DB|
|Primary Usage Feature||Conventional Databases||Datawarehouse||Database for dynamically modified data|
|Database Engine||MySQL, Oracle DB, SQL Server, Amazon Aurora, Postgre SQL||Redshift||NoSQL|
|Computing Resources||Instances with 64 vCPU and 244 GB RAM
|Nodes with vCPU and 244 GB RAM||Not specified, SaaS-Software as a Service.|
|Multi A-Z Replication||Additional Service||Manual||In-built|
|Maintenance Window||30 minutes every week.||30 minutes every week.||No impact|
Q38. If you hold half of the workload on the public cloud whereas different half is on local storage, in such case what type of architecture can be used?
Ans. In such cases, the hybrid cloud architecture can be used.
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Q39. Mention the possible connection issues you encounter when connecting to an EC2 instance?
Ans. Following are the possible connection issues you encounter when connecting to an EC2 instance:
- Server refused key
- Connection timed out
- Host key not found, permission denied.
- Unprotected private key file
- No supported authentication method available
Q40. What are lifecycle hooks in AWS autoscaling?
Ans. Lifecycle hooks can be added to the autoscaling group. It enables you to perform custom actions by pausing instances where the autoscaling group terminates and launches them. Every auto-scaling group consists of multiple lifecycle hooks.
Q41. What is a Hypervisor?
Ans. A Hypervisor is a type of software used to create and run virtual machines. It integrates physical hardware resources into a platform which are distributed virtually to each user. Hypervisor includes Oracle Virtual Box, Oracle VM for x86, VMware Fusion, VMware Workstation, and Solaris Zones.
Q42. Explain the use of Route Table.
Ans. Route Table is used to control the network traffic where each subnetwork of VPC is associated with a routing table. Route table consists of huge information, whereas connecting multiple subnetworks to a routing table is also feasible.
Q43. What is the use of Connection Draining?
Ans. Connection Draining is a process used to support load balancer. It keeps tracking all of the instances if any instance fails connection draining drag all the traffic from that specific failed instance and re-route the traffic to the active instances.
Q44. Explain the role of AWS CloudTrail?
Ans. AWS CloudTrail is a service designed for monitoring and auditing actions of API calls. With AWS CloudTrail, the user can monitor and retain account activity connected with actions covering the AWS infrastructure.
Q45. Explain the use of Amazon Transfer Acceleration Service?
Ans. Amazon Transfer Acceleration Service is used to boost your data transfer with the help of advanced network paths. It also transfers files fast and secures between your client and an S3 bucket.
Q46. How to update AMI tools at the Boot-Time on Linux?
Ans. To update AMI tools at the Boot-Time on Linux:
# Update to Amazon EC2 AMI tools
echo ” + Updating EC2 AMI tools”
yum update -y aws-amitools-ec2
echo ” + Updated EC2 AMI tools”
Q47. How does Encryption is done in S3?
Ans. Encryption is done in S3 by using:
- In Transit: SSL/TLS
- At Rest
- Server-Side in Encryption
- S3 Managed Keys – SSE-S3
- AWS Key Management Service, Managed of Keys – SSE-KMS
- 6.Server-Side Encryption with Customer Provided Keys – SSE-C
- Client-Side Encryptions
Q48. Explain Amazon Route 53?
Ans. Amazon Route 53 is defined as a scalable and highly available Domain Name System (DNS). It is created for the benefit of developers and companies to route end users to internet applications by translating names which is the most reliable and cost-effective process.
Q49. What are the pricing models for EC2 instances?
Ans. Following are the different pricing model for EC2 instances:
Q50. What are the parameters for S3 pricing?
Ans. Following are the parameters for S3 pricing:
- Transfer acceleration
- Number of requests you make
- Storage management
- Data transfer
- Storage used
Q51. What are the best security practices for Amazon EC2?
Ans. Below are the steps to follow for secure Amazon EC2 best practices:
- Using AWS identity and access management to manage access to the AWS resource.
- Exclude access by initializing trusted hosts or networks to access ports on our instance.
- Evaluate the rules in your security groups.
- Stop passport login, for instance, opened from your AMI
Q52. How do you add a current instance to a new Autoscaling group?
Ans. Follow the steps to know how you can add an existing instance to a new auto-scaling group:
- Launch EC2 console
- Under instances select your instance
- Choose the action, instance setting and attach to the auto-scaling group
- Select a new auto-scaling group
- Comply with this group to the instance
- If needed edit the instance
- In the end, you can add the instance to a new auto-scaling group successfully.
Q53. Name the different types of instances.
Ans. Following are the different types of instances:
- Accelerated computing
- Storage optimize
Q54. Mention the different layers of cloud architecture.
Ans. Following are the different types of layers in cloud architecture:
- Node controller
- Cloud controller
- Cluster controller
- Storage controller
Q55. What are the edge locations?
Ans. An edge location is defined as the place where the content is used to be cached. If a user finds to access some content, then the given content will be searched in the edge location. If it is not available, then the content will be accessible from the origin location, and a copy will be stored.
Q56. What are NAT gateways?
Ans. NAT(Network Address Translation) used to enable instances in a private subnet that helps to connect to the internet but avoid the internet from starting a connection with those instances.
Q57. Name the database types in RDS?
Ans. Following are the types of databases in RDS:
- MYSQL server
- SQL server
Q58. What are EBS Volumes?
Ans. Elastic Block Store(EBS) is a block-level storage device, wherein each block acts as a separate hard drive. These volumes are used with EC2 instances, and each EBS volume can be attached to only one EC2 instance.
Q59. Name the types of backups in the RDS database.
Ans. Following are two types of backups in the RDS database:
- Automated backups
- Manual backups
Q60. Mention the benefits of auto-scaling.
Ans. Following are some of the benefits of auto-scaling:
- Better availability
- Better fault tolerance
- Better cost management
Q61. How can Amazon SQS be used?
Ans. Amazon SQS (Simple Queue Service) is a message passing mechanism used to make a connection between different connectors that are connected with each other. It is also used as an interlink between multiple components of Amazon.
Q62. Name some examples of the DB engine that is used in AWS RDS.
Ans. Below are the few examples of DB engine that is used in AWS RDS:
- MS-SQL DB
- MYSQL DB
- Maria DB
- Oracle DB
- Postgre DB
Q63. Is it possible to minimize an EBS volume?
Ans. No, it is not possible to minimize volume, we can only increase it.
Q64. Is there any possible way to restore the deleted S3 bucket?
Ans. We can only restore it when versioning is enabled.
Q65. Name the types of AMI provided by AWS?
Ans. Following are two types of AMI provided by AWS:
- Instance Store backed
- EBS Backed
Q66. What is auto-scaling?
Ans. Auto-scaling is a feature of AWS which allows you to configure and automatically provision and spin-up new instances without the need for your intervention.
Q67. What is SimpleDB?
Ans. SimpleDB is a structured data store that supports indexing and data queries to both EC2 and S3.
Q68. What is an AMI?
Ans. AMI (Amazon Machine Image) is a snapshot of the root filesystem.
Q69. What is the type of architecture, where half of the workload is on the public load while at the same time half of it is on the local storage?
Ans. Hybrid cloud architecture.
Q70. Can I vertically scale an Amazon instance? How do you do it?
Ans. Yes. Spinup a new larger instance than the one you are running, then pause that instance to detach the root EBS volume from this server and discard. After that, stop the live instance and detach its root volume. Note the unique device ID and attach that root volume to the new server, and start again. This way you will have scaled vertically.
Q71. How can you send a request to Amazon S3?
Ans. You can send requests by using the REST API or the AWS SDK wrapper libraries that wrap the underlying Amazon S3 REST API.
Q72. How many buckets can be created in AWS by default?
Ans. By default, 100 buckets can be created in AWS by default.
Q73. Should encryption be used for S3?
Ans. Encryption should be considered for sensitive data as S3 is a proprietary technology.
Q74. What are the various AMI design options?
Ans. Fully Baked AMI, JeOS (just enough operating system) AMI, and Hybrid AMI.
These are some of the popular AWS interview questions. If you are someone who has recently started your career in cloud computing, you can always get certified in one of the technical courses like AWS Architect to get the requisite knowledge and skills.
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