AWS Lambda Interview Questions and Answers

These AWS Interview Questions have been designed specially to get you acquainted with the nature of questions you may encounter during your interview for the subject of AWS.

As per my experience good interviewers hardly plan to ask any particular question during your interview, normally questions start with some basic concept of the subject and later they continue based on further discussion and what you answer.

1. What Is AWS Lambda?

Ans:

AWS Lambda is an Amazon serverless computing system that runs code and automatically manages your underlying compute resources.

It lets you automatically run code in response to many types of events, such as HTTP requests from Amazon API gateway, table updates in Amazon DynamoDB, and state transitions. It also enables you to extend to other AWS services with custom logic, and even create your own back-end services.

2. How Does AWS Lambda Work?

Ans:

AWS Lambda may seem confusing at first, it really isn’t. In fact, it’s actually just a 4-step simple process.

Start off by uploading your code to AWS Lambda. From there, set up your code to trigger from other AWS services, HTTP endpoints, or mobile apps.

AWS Lambda will only run your code when it’s triggered and will also only use the computing resources needed to run it.

3. What’s better? You only have to pay for the compute time you use!What are the Advantages of AWS Lambda?

Ans:

1. 1. AWS Lambda offers a variety of benefits to its users. Here are 3 of the biggest benefits you should know about when deciding if AWS Lambda is right for you:
2. 2. It Doesn’t Require You to Manage Any Servers
3. 3. Since AWS Lambda automatically runs your code there’s no need for you to manage the server. Simply write your code and upload it to Lambda and you’re good to go.
4. 4. It Empowers You to Easily Scale

4. What Can You Build with AWS Lambda?

Ans:

AWS Lambda can build a variety of things. Here’s a quick list of just a few use cases for it:

• Data processing
• Real-time file processing
• Data validation
• Filtering
• Sorting
• Real-time stream processing
• 3rd-party API requests

5. How Much Does AWS Lambda Cost?

Ans:

As previously mentioned, with AWS Lambda you only pay for what you use, factoring in the number of requests and duration of your code.

Lambda considers a request to be each time it starts executing in response to a trigger such as an event notification or an invocation volume. The duration of the code is calculated from the moment your code begins executing until it returns or is terminated.

6. Define Amazon Web Services or AWS.

Ans:

According to the terminology, AWS or Amazon Web Services is defined as a platform which is designed to provide secure cloud services, computing power to clients, database storage options, content delivery and many other services which are all intended towards business development and growth.

7. List out the main components of AWS.

Ans:

1. 1. Similar to other Cloud Services in the industry, AWS too has been designed in a structured manner and has several key components.
2. 2. Mentioned below is the list of the same: Easy Email Service: This service allows customers and clients to address email utilization through normal SMTP or RESTFUL API.
3. 3. Access Management and Identity: This has been designed in order to provide heightened identity control and protection for a client’s AWS account.

8. What do you know about Buffer in AWS?

Ans:

A buffer is necessary in any cloud computing technology in order to maintain seamless integration across a huge flow of traffic and loads. The Elastic Load Balancer in Amazon Web Services has been designed in a way to ensure that all the incoming traffic is optimally distributed across all channels of AWS instances.

The presence of a buffer enables the components to work in an unstable situation and receive and process requests as it gets them. Essentially the presence of a buffer is needed to create an equilibrium between all the apparatus and provide them with an identical ability to supply more rapid services.

9. How can you secure your data in the cloud?

Ans:

One of the most important aspects of cloud computing is its security. It must be ensured at all times that no individual or organization is able to seize the data of a client while in a transition from one point to another and also there shouldn’t be any leakage of information from any of the several storerooms in the cloud.

Thus one of the most effective ways of securing information is by segregating it and then encrypting the same by one of the mutually agreed options.

10. List out the different services offered by cloud computing.

Ans:

There have been a number of public and private cloud platforms developed these days. All of these are composed of several services/layers of cloud computing.

Mentioned below is a list of the same:

• PaaS: It is the acronym for Platform as a Service.
• IaaS: It is the acronym for Infrastructure as a Service.
• SaaS: It is the acronym for Software as a Service.

11. Can Amazon Instance be vertically scaled? If yes, how?

Ans:

Yes, it is very much possible to vertically scale an Amazon Instance. Here’s how: 

1. 1. Form and twist a fresh massive instance on top of the currently governing instance.
2. 2. Make an attempt to delay the current instance and separate the source web mass of dispatch and server.
3. 3. The next step is to quit your existing instance and separate the same from source quantity.
4. 4. Take note of the new machine ID and connect the same source mass to your fresh server.

12. Name the basic components of Amazon Web Services.

Ans:

Amazon Web Services or AWS consists of 4 main components that are as listed below:

1. 1. Amazon S3: This component has been designed to enable one to retrieve information which has been occupied in creating the cloud structural design and also retrieve the produced information as a consequence of the specified key.
2. 2. Amazon EC2 instance: This component has been designed in order to run automatic parallelization and also achieve job scheduling. This instance is immensely helpful in running a large distributed system on the Hadoop Cluster.
3. 3. Amazon SimpleDB: This component helps in the storage of the transitional positional log and also run the errands when they are executed by the client or the consumer.
4. 4. Amazon SQS: This component has been mainly designed to act as a mediator between different controllers. This is an additional cushioning for the managers at Amazon.

13. Define Amazon EC2.

Ans:

Amazon EC2 service is the acronym for Amazon Elastic Compute Cloud which has been designed to provide its customers with resizable and scalable computing capacity when they are using the cloud.

Using the service of Amazon EC2, a client is able to launch as many virtual servers as he wants. In each of these virtual servers, the client is able to manage storage as well as configure security as and when needed.

The main advantage of using Amazon EC2 is its ability to get everything done with minimal friction at all times.

14. List out all the best security practices for AWS EC2.

Ans:

• As a client who is using the service of Amazon EC2, there are some security best practices that needs to be followed at all times.
• The same is as outlined below.Use the AWS identity and access management to control and limit access to all your AWS resources at all times.

15. Explain Stopping, Starting, and Terminating an Amazon EC2 instance.

Ans:

1. 1. Stopping and Starting an instance are the most common commands used on the Amazon EC2 platform.
2. 2. Questions based on these commands are considered one of the best AWS interview questions.
3. 3. Mentioned below is the explanation of the commands.
4. 4. Once the command for stopping an instance is issued, the instance first performs a normal shutdown and then transitions itself to a stopped state.
5. 5. All the Amazon EBS volumes remained attached as they were, and you can resume the instance at a later stage.
6. 6. One of the main advantages of this feature is that Amazon doesn’t charge you additionally for the hours while the instance was in a stopped state.

16. Can S3 be cast-off with EC2 Instances, If yes specify how?

Ans:

Yes, it is possible to cast off with EC2 instances by using root approaches which have the backup of native occurrence storage.

When a developer or a client is using Amazon S3 services, they have the capability to use extremely scalable and additionally fast, dependable, low priced data storage structures that are used by Amazon itself to track the worldwide network of its own websites.

17. Define regions and availability zones in Amazon EC2.

Ans:

Being such a mammoth in the industry, it is common knowledge that Amazon EC2 will be hosted in multiple locations across the world. These worldwide locations are categorized in terms of availability zones as well as regions.

Each of these regions is completely independent of the other and each availability zone is isolated as well. But all the availability zones in a particular region are interconnected through multiple low latency links.

18. What is Amazon EC2 Root Device Volume?

Ans:

When you as a developer launch an instance, the root device volume has the image that was used to boot up the instance in the first place.

There are two types of AMIs or Amazon Machine Images that are available:

1. 1. EBS based storage
2. 2. Instance store-backed AMI

19. Are you aware of Security Group in Amazon EC2? Tell something about it.

Ans:

Security groups in Amazon EC2 are one of the ways through which the security of the cloud network is protected.

They act as a firewall and are used for controlling both the inbound as well as outbound traffic at the level of the instance.

20. Which of the following is a method for bidding on unused EC2 capacity based on the current spot price?

Ans:

Spot Instance is the best method for bidding on unused EC2 capacity since this feature requires an affordable low price and the availability of the system varies depending on the availability of excess capacity.

21. Is this statement wrong, why? “The standard instances are not suitable for standard server applications”

Ans:

Yes, the statement is wrong because the standard instances are deemed suitable only for standard server applications.

22. Which instance has an hourly rate with no long-term commitment?

Ans:

On-Demand Instance has an hourly rate with no long-term commitment because the pricing of this feature varies with the pricing model, instance as well as zone.

23. Which Amazon cloud-based storage system allows you to store data objects ranging in size from 1 byte up to 5GB?

Ans:

Amazon S3 cloud-based storage system allows you to store data objects ranging in size from 1 byte up to 5GB. It is because, in S3 containers, storage containers are often referred to as buckets.

24. Which operation retrieves the newest version of the object?

Ans:

GET operation retrieves the newest version of the object since the versioning can also be used for archiving purposes as well as preserving data.

25. How can the request be sent to Amazon S3?

Ans:

As we all know that Amazon S3 is a rest service. The request can be sent either by using the REST API or using AWS SDK wrapper libraries which can be used to wrap the Amazon S3 REST API.

26. How to secure files in Amazon S3?

Ans:

Autoscaling and load balancer are the important features of AWS services and the interviewer may ask many of the AWS interview questions based on these features in the interview.

These important topics can’t be ignored, so here we cover AWS interview questions based on Autoscaling and load balancer.

27. What is auto-scaling and how does it work?

Ans:

Auto-scaling is one of the most important features that Amazon Web Service provides that gives you an allowance to configure and automatically stipulate and also twists new instances without even your intervention.

This can be done by setting the edges and measurements to screen. At the point when those edges have crossed another instance based on your preference will be spun up, rolled, and configured into the load balancer pool.

Now, you would’ve scaled that horizontally without the intervention of an operator.

28. What is Server Load Balancing?

Ans:

SLB (Server Load Balancing) provides the performance of the network and also it delivers the content by the implementation of a series of priorities as well as algorithms which helps in responding to the precise requests that are made to the network.

In other words Server Load Balancing (SLB) takes the part of distributing the clients to a vast group of some servers and that also ensures that the clients which are sent are only sent to the specific servers and not to the failed servers.

29. What is Global Server Load Balancing (GSLB) and does Clustering need to be turned on in order to use GSLB?

Ans:

GSLB (Global Server Load Balancing) is very much similar to SLB (Server Load Balancing) but GSLB takes SLB to a global scale. It authenticates us to stack balance VIPs from various geographical locations as well as a single entity.

From this, the geographic site gets scalability and fault tolerance.

30. What are the automation tools that can be used to spin up the servers?

Ans:

The use of AWS API is the most prominent way to roll your own scripts. The scripts like this can be written in any language of one’s choice like bash or python.

Another option is that we can use configuration management and also provisioning the tool like its puppet or it can be better when the successor Opcode Chef can be used.

31. What are those load balancing methods which are supported with array network GSLB and also explain Reverse Proxy Cache?

Ans:

The following methods of Global Server Load Balancing are supported by Array appliance.

• Overflow: Overflow method allows all the requests to be sent to the different remote site when the local site id loaded up to 80%
• lc: “lc” here stands for Least Connections, it sends the clients to the site which has the least count of current connections.
• rr: “rr” here stands for Round Robin, it sends the clients in the round robin suction to each site.

32. What are the challenges in microservices debugging and troubleshooting?

Ans:

1. 1. In the serverless world, debugging and troubleshooting is the most difficult process.
2. 2. The log error and warning messages are logged in CloudWatch.
3. 3. This is the area that needs attention and Amazon is working on it.

33. What is Elastic Beanstalk?

Ans:

Elastic Beanstalk provides the basic services which help in the creation of Environment. It also provides services like managing the application environments which include the creation of logs, health, and monitoring, etc.

34. Mention few benefits of the elastic beanstalk.

Ans:

The Beanstalk is easy for beginners and most flexible. Deployment of the application on AWS is easy. Various tools like Visual Studio are used to upload the applications.

The deployment details of capacity monitoring and auto-scaling can be easily managed by AWS Beanstalk.

Demand Scaling: The application can be auto-scaled which helps in the handling of workload or traffic while minimizing the cost for the application.

35. Mention some of the advantages of AWS Elastic Beanstalk.

Ans:

Some of the benefits of AWS EBS are as follows:

1. 1. EBS is economical with no hidden costs. You will pay what you will use.
2. 2. The AWS management console can be accessed within an hour with its fast access.
3. 3. IT supports languages like Java, .NET, PHP, Node.js, Python, Ruby, etc.
4. 4. AWS EBS builds the setup and spectators the AWS service for the creation of web services.

36. What are the operating systems used by Elastic Beanstalk?

Ans:

AWS Beanstalk requires a stable, high-performance, secure environment for execution for Amazon EC2 cloud computing.

So there are two EMI’s which are maintained by AWS. Amazon Linux AMI and Windows Server 2012 R2 AMI are two OS which runs Amazon Elastic Beanstalk.

37. How to make any application private?

Ans:

In myapp.elasticbeanstalk.com the application is public by default. Amazon VPC should be used to make the virtual network private. Specific security group rules are also there to make the application private.

38. What do you mean by AWS Lambda?

Ans:

1. 1. If you talk about a serverless compute service then AWS Lambda offers the best service.
2. 2. The codes can be run and managed without managing servers.
3. 3. You just pay for the consumption of data in computing.
4. 4. When you are idle you do not have to pay anything.
5. 5. Just an upload of code is needed and rest is managed by Lambda.

39. Mention the time span in which the AWS Lambda function will execute.

Ans:

All the process of AWS Lambda and execution takes place within 300 seconds from placing calls to AWS Lambda. The default timeout is 3 seconds rest you can setup any value between 1 to 300 seconds.

40. Can Lambda be vertically scaled? If yes, how?

Ans:

• This is one of the most prominent features of AWS Lambda.
• When a larger instance is to be spin then we use vertical scaling.
• If there is scaling in use then it has to be paused and has to be detached from the server.
• The ID of new device post is to be noted down to continue the process.

41. Mention the role of SQS in Lambda.

Ans:

There is a certain approach which is used for sharing of information and passing that information among different hosts and connectors and communication can be established. The functional components could be connected even if they are different.

There are many advantages of using SQS and several of the failures are eliminated.

42. What are the Final variables?

Ans:

Once assigned these variables cannot be changed. In its earlier stage, they are known as effective variables where any form of change is possible and the values are assigned to them.

They also play an important role in testing. Most of the local expressions are final.

43. How can performance be improved in Lambda?

Ans:

There are some of the methods by which performance can be improved in Lambda.

You can improve the performance by using Linux software RAID and with the help of RAID, we can be assured of better security.

44. Define Automate Deployment.

Ans:

This method is similar in many ways to programming in other languages. However, the unique advantages of this platform is that it helps in cutting down a lot of challenges.

One of the best things is, the deployment can be made as one becomes more proficient with other offerings of the service.

Using Automated deployment clients can minimize human interference and also ensure that the outcomes are quality based in every aspect.

45. List out the different ways to access EC2.

Ans:

• EC2 can be accessed both via web-based Interface and also Command Line Interface.
• Additionally, there are Powershell tools available in Windows which can be simply executed.

46. What are the advantages of using the serverless approach?

Ans:

Using the serverless approach has multiple advantages.

Mentioned below is a list of the same:

1. 1. The approach is utterly simple which converts to quicker time to market and thus higher sales.
2. 2. Clients are only required to pay when the code is in operation, thus a huge amount of money can be saved in enhanced profits.
3. 3. Clients do not need any additional infrastructure in order to run this application.
4. 4. Clients do not need to give any second thought on the server which is running the code.

47. Is it possible to debug and troubleshoot the small or microservices?

Ans:

Yes, it is very much possible to debug and troubleshoot small as well as microservices.

The unique feature enables it to be done even when appropriate tasks are being performed in the background.

48. Why is Lambda regarded as a time-saving approach?

Ans:

The main reasons due to which Lambda is considered as a time-saving approach are as follows:

• All the data can be simply stored in the local server memory.
• The data can be stored directly into the database without affecting their performance.
• Integration testing is highly powerful and can be made through multiple vendors.

49. What is your opinion About Zero Downtime Deployment?

Ans:

Deployments are most commonly considered in the form of functions.

The advantageous feature of AWS Lambda is that it divides the functions into cases when they are hugely complex. The app in these scenarios remains offline during such a time period, but the end result is always great and of high quality.

50. Define Amazon Cloudwatch.

Ans:

As mentioned above, Amazon CloudWatch is a management tool and is a part of the Amazon Web Services family. It is basically a monitoring service for AWS cloud resources and all applications run on the AWS platform.

CloudWatch can be used to track and collect metrics, set alarms, collect and monitor log files, and also monitor resources such as EC2 instances, RDS DB instances, and DynamoDB tables.

51. Name the operating systems on which CloudWatch runs.

Ans:

CloudWatch is a truly versatile system and it is capable of receiving and providing metrics for all EC2 instances and currently works on any operating system supported by EC2.

52. What kinds of things can I do with CloudWatch logs?

Ans:

As CloudWatch is capable of storing and monitoring a client’s logs and help them better understand how their systems and applications are operating.

CloudWatch can be used to log in multiple ways, which are as mentioned below:

1. 1. Long-term log retention
2. 2. Real-Time application and system monitoring

53. Which platforms support CloudWatch Logs Agent?

Ans:

The CloudWatch logs agent is supported by a number of operating systems and platforms. The list of the same is as mentioned below:

• CentOS
• Amazon Linux
• Ubuntu
• Red Hat Enterprise Linux
• Windows

54. Does the CloudWatch logs agent support IAM roles?

Ans:

Yes, the CloudWatch logs agent is very much capable of supporting and integrating with IAM and has access to both keys and IAM roles.

55. List out the retention period of all metrics.

Ans:

CloudWatch retains all its metrics accordingly as mentioned in the table below.

Any data points or high-resolution custom metrics with a span of fewer than 60 seconds are available for 3 hours.

1. 1. Data points with a period of 60 seconds are available for 15 days.
2. 2. Data points with a period of 5 minutes are available for 63 days.
3. 3. Data points with a period of 1 hour are available for 455 days or 15 months.

56. What Are Some of the Security Best Practices for Amazon EC2?

Ans:

Security best practices for Amazon EC2 include using Identity and Access Management (IAM) to control access to AWS resources; restricting access by only allowing trusted hosts or networks to access ports on an instance; only opening up those permissions you require, and disabling password-based logins for instances launched from your AMI.

57. What Is Amazon S3?

Ans:

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. 

58. Can S3 Be Used with EC2 Instances, and If Yes, How?

Ans:

Amazon S3 can be used for instances with root devices backed by local instance storage.

That way, developers have access to the same highly scalable, reliable, fast, inexpensive data storage infrastructure that Amazon uses to run its own global network of websites.

To execute systems in the Amazon EC2 environment, developers load Amazon Machine Images (AMIs) into Amazon S3 and then move them between Amazon S3 and Amazon EC2.

59. What Is Identity Access Management (IAM) and How Is It Used?

Ans:

I dentity 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.

60. What Is Amazon Virtual Private Cloud (VPC) and Why Is It Used?

Ans:

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.

61. What Is Amazon Route 53?

Ans:

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.

62. What Is Cloudtrail and How Do Cloudtrail and Route 53 Work Together?

Ans:

CloudTrail is a service that captures information about every request sent to the Amazon Route 53 API by an AWS account, including requests that are sent by IAM users.

CloudTrail saves log files of these requests to an Amazon S3 bucket. CloudTrail captures information about all requests.

You can use information in the CloudTrail log files to determine which requests were sent to Amazon Route 53, the IP address that the request was sent from, who sent the request, when it was sent, and more.

63. When Would You Prefer Provisioned IOPS over Standard Rds Storage?

Ans:

You would use Provisioned IOPS when you have batch-oriented workloads.

Provisioned IOPS delivers high IO rates, but it is also expensive. However, batch processing workloads do not require manual intervention. 

64. How Do Amazon Rds, Dynamodb, and Redshift Differ from Each Other?

Ans:

Amazon RDS is a database management service for relational databases. It manages patching, upgrading, and data backups automatically. It’s a database management service for structured data only.

On the other hand, DynamoDB is a NoSQL database service for dealing with unstructured data.

Redshift is a data warehouse product used in data analysis.

65. What Are the Benefits of AWS’s Disaster Recovery?

Ans:

• Businesses use cloud computing in part to enable faster disaster recovery of critical IT systems without the cost of a second physical site.
• The AWS cloud supports many popular disaster recovery architectures ranging from small customer workload data center failures to environments that enable rapid failover at scale.
• With data centers all over the world, AWS provides a set of cloud-based disaster recovery services that enable rapid recovery of your IT infrastructure and data.

66. What type of performance can you expect from Elastic Block Storage? How do you back it up and enhance the performance ?

Ans:

1. 1. Performance of an elastic block storage varies i.e. it can go above the SLA performance level and after that drop below it.
2. 2. SLA provides an average disk I/O rate  which can at times frustrate performance experts who yearn for reliable and consistent disk throughput on a server.
3. 3. Virtual AWS instances do not behave this way.
4. 4. One can backup EBS volumes through a graphical user interface like elasticfox or use the snapshot facility through an API call.

Also, the performance can be improved by using Linux software raid and striping across four volumes.

67. Imagine that you have an AWS application that requires 24×7 availability and can be down only for a maximum of 15 minutes. How will you ensure that the database hosted on your EBS volume is backed up?

Ans:

• Automated backup are the key processes here as they work in the background without requiring any manual intervention.
• Whenever there is a need to back up the data, AWS API and AWS CLI play a vital role in automating the process through scripts.
• The best way is to prepare for a timely backup of EBS of the EC2 instance.
• The EBS snapshot should be stored on Amazon S3 and can be used for recovery of the database instance in case of any failure or downtime.

68. You create a Route 53 latency record set from your domain to a system in Singapore and a similar record to a machine in Oregon. When a user located in India visits your domain, to which location will he be routed to?

Ans:

Assuming that the application is hosted on Amazon EC2 instance and multiple instances of the applications are deployed on different EC2 regions.

The request is most likely to go to Singapore because Amazon Route 53 is based on latency and it routes the requests based on the location that is likely to give the fastest response possible.

69. Differentiate between on-demand instance and spot instance.

Ans:

Spot Instances  are spare unused EC2 instances which one can bid for. Once the bid exceeds the existing spot price (which changes in real-time based on demand and supply) the spot instance will be launched.

If the spot price becomes more than the bid price then the instance can go away anytime and terminated within 2 minutes of notice.

The best way to decide on the optimal bid price for a spot instance is to check the price history of last 90 days that is available on AWS console.

The advantage of spot instances is that they are cost-effective and the drawback is that they can be terminated anytime.

70. How will you access the data on EBS in AWS ?

Ans:

Elastic block storage as the name indicates provides persistent, highly avaialble and high performance block level storage that can be attached to a running EC2 instance.

The storage can formatted and mounted as a file system or the raw storage can be accessed directly.

71. What is the boot time for an instance store backed instance ?

Ans:

Following are the steps to scale an Amazon Instance vertically –

1. 1. Spin up a larger Amazon instance than the existing one.
2. 2. Pause the exisiting instance to remove the root abs volume from the server  and discard. Stop the live running instance and detach its root volume.
3. 3. Make a note of the unique device ID and attach that root volume to the new server. Start the instance again.

72. Differentiate between vertical and horizontal scaling in AWS.

Ans:

The main difference between vertical and horizontal scaling is the way in which you add compute resources to your infrastructure.

In vertical scaling, more power is added to the existing machine while in horizontal scaling additional resources are added into the system with the addition of more machines into the network so that the workload and processing is shared among multiple devices.

The best way to understand the difference is imagine that you are retiring your Toyota and buying a Ferrari because you need more horsepower.

This is vertical scaling. Another way to get that added horsepower is not to ditch the Toyota for the Ferrari but buy another car.

This can be related to horizontal scaling where you drive several cars all at once.

73. What is the total number of buckets that can be created in AWS by default ?

Ans:

100 buckets can be created in each of the AWS accounts. If additional buckets are required, increase the bucket limit by submitting a service limit increase.

74. Differentiate between Amazon RDS, Redshift and Dynamo DB.

Ans:

An organization wants to deploy a two-tier web applications on AWS.  The application requires complex query processing and table joins.

However, the company has limited resources and requires high availability. 

75. Which is the best configuration that company can opt for based on the requirements ?

Ans:

DynamoDB deals with core problems of database scalability, management, reliability, and performance but does not have the functionalities of a RDBMS.

DynamoDB does not render support for complex joins or query processing or complex transactions.  You can run a relational engine on Amazon RDS or EC2 for this kind of a functionality.

76. If you have half of the workload on public cloud while the other half is on local storage, what kind of architecture will you use for this ?

Ans:

Hybrid Cloud Architecture

77. Is it possible to cast-off S3 with EC2 instances ? If yes, how ?

Ans:

It is possible to cast-off S3 with EC2 instances using root approaches backed by native occurrence storage.

78. How will you configure an instance with the application and its dependencies , and make it ready to serve traffic?

Ans:

1. 1. You can acheive this with the use of lifecycle hooks.
2. 2. They are powerful as they let you pause the creation or termination of an instance so that you can sneak peak in and perform custom actions like configuring the instance, downloading the required files, and any other steps that are required to make the instance ready.
3. 3. Every auto scaling group can have multiple lifecycle hooks.

79. How can you safeguard EC2 instances running on a VPC ?

Ans:

AWS Security groups associated with EC2 instances can help you safeguard EC2 instances running in a VPC by providing security at the protocol and port access level.

You can configure both INBOUND and OUTBOUND traffic to enables secured access for the EC2 instance.

AWS security groups are much similar to a firewall-they contain set of rules which filter the traffic coming into and out of an EC2 instance and deny any kind of unauthorized access to EC2 instances.

80. How many EC2 instances can be used in a VPC ?

Ans:

There is a limit of running up to a total of 20 on-demand instances across the instance family , you can purchase 20 reserved instances and request spot instances as per your dynamic spot limit region.

81. What are some of the key best practices for security in Amazon EC2?

Ans:

Create individual IAM (Identity and Access Management) users to control access to your AWS recourses.

Creating separate IAM user provides separate credentials for every user making it possible to assign different permissions to each user based on the access requirements.

82. What should be the instance’s tenancy attribute for running it on a single tenant hardware ?

Ans:

The instance tenancy attribute must be set to a dedicated instance and other values might not be appropriate for this operation.

There is a distributed application that processes huge amounts of data across various EC2 instances.  Application is designed in such a way that it can recover gracefully from EC2 instance failures.

83. How will you accomplish this in a cost effective manner ?

Ans:

• On-demand or reserved instance will not be ideal in this case as the task here is not continuous.
• Moreover. It does not make sense to launch an on-demand instance whenever work comes up because on-demand instances are expensive.
• In this case, the ideal choice would be to opt for a spot instance owing to its cost effectiveness and no long term commitments.

84. What are the important features of a classic load balancer in EC2 ?

Ans:

The high availability feature ensures that the traffic is distributed among EC2 instances in single or multiple availability zones.

This ensures high scale of availability for incoming traffic.

85. What parameters will you take into consideration when choosing the availability zone ?

Ans:

Performance, pricing, latency, and response time are some of the factors to consider when selecting the availability zone.

86. Which instance will you use for deploying a 4-node Hadoop cluster in AWS ?

Ans:

We can use a c4.8x large instance or i2.large for this, but using a c4.8x will require a better configuration on PC.

87. Will you use encryption for S3 ?

Ans:

It is better to consider encryption for sensitive data on S3 as it is a proprietary technology.

88. How can you send request to Amazon S3 ?

Ans:

Using the REST API or the AWS SDK wrapper libraries which wrap the underlying Amazon S3 REST API.

89. How will you bind the user session with a specific instance in ELB (Elastic Load Balancer) ?

Ans:

This can be achieved by enabling Sticky Session.

90. You are launching an instance under the free usage tier from AMI having a snapshot size of 50GB. How will you launch the instance under the free usage tier ?

Ans:

It is not possible to launch this instance under the free usage tier.

91. Which load balancer will you use to make routing decisions at the application layer or transport layer that  supports either VPC or EC2?

Ans:

Classic Load Balancer

92. You have a webserver on EC2 instance . Your instance can get to the web but nobody on the internet can get to your webserver. How will you troubleshoot this issue ?

Ans:

1. 1. Static content for the application is on S3 and is distributed using CloudFront.
2. 2. The auto scaling group is set to trigger a scale up event with 60% CPU utilization.
3. 3. You use extra large DB instance with 10.000 Provisioned IOPS that gives CPU Utilization around 80% with freeable memory in the 2GB range.
4. 4. The web analytics report shows that the load time for the webpages is an average of 2 seconds but the SEO consultant suggests that you bring the average load time of your pages to less than 0.5 seconds.
5. 5. What will you do improve the page load time of the website for your users.

93. What if Google decides to host YouTube.com on AWS, how will you design the solution architecture ?

Ans:

If you really love AWS and want to push forward on AWS certifications for sure, these AWS solutions architect interview questions will help you get through the door. 

94. What are the possible connection issues you encounter when connecting to an EC2 instance ?

Ans:

• Unprotected private key file
• Server refused key
• Connection timed out
• No supported authentication method available
• Host key not found,permission denied.
• User key not recognized by the server, permission denied.

95. What is the difference between Amazon S3 and EBS ?

Ans:

1. 1. Paradigm
2. 2. Object Store
3. 3. Filesystem
4. 4. Security
5. 5. Private Key or Public Key
6. 6. Visible only to your EC2
7. 7. Redundancy
8. 8. Across data centers
9. 9. Within the data center
10. 10. Performance
11. 11. Fast
12. 12. Superfast

96. Can you run multiple websites on an EC2 server using a single IP address?

Ans:

More than one elastic IP is required to run multiple websites on EC2.

97. What happens when you reboot an EC2 instance?

Ans:

Rebooting an instance is just similar to rebooting a PC.

You do not return to image’s original state, however, the contents of the hard disk are same as before the reboot.

98. How will you reduce the load on EC2 instance ?

Ans:

This can be done by attaching a load balancer to an autoscaling group to efficiently distribute load among all instances.

99. What happens when you launch instances in Amazon VPC ?

Ans:

Each instance has a default IP address when the instance is launched in Amazon VPC.

This approach is considered ideal when you need to connect cloud resources with the data centers.