1.What is Amazon EC2 service?
Amazon Elastic Compute Cloud (Amazon EC2) is a Amazon web service that provides resizable (scalable) computing capacity in the cloud. You can use Amazon EC2 to launch as many virtual servers you need. In Amazon EC2 you can configure security and networking as well as manage storage. Amazon EC2 service also helps in obtaining and configuring capacity using minimal friction.
2. What is Amazon Machine Image (AMI)?
An Amazon Machine Image (AMI) is a template that contains a software configuration (for example, an operating system, an application server, and applications). From an AMI, we launch an instance, which is a copy of the AMI running as a virtual server in the cloud. We can even launch multiple instances of an AMI.
3. What is S3? What is it used for? Should encryption be used?
S3 stands for Simple Storage Service. You can think of it like FTP storage, where you can move files to and from there, but not mount it like a filesystem. AWS automatically puts your snapshots there, as well as AMIs there. Encryption should be considered for sensitive data, as AWS S3 is a proprietary technology developed by Amazon themselves, and as yet unproven vis-a-vis a security standpoint.
4. What automation tools can I use to spin up servers?
The most obvious way is to roll-your-own scripts, and use the AWS API tools. Such scripts could be written in bash, Perl or another language or your choice. The next option is to use a configurationmanagement and provisioning tools like puppet or better it’s successor Opscode Chef. You might also look towards a tool like Scalr. Lastly, you can go with a managed solution such as Right scale.
5. How to use Amazon SQS?
Amazon SQS (Simple Queue Service) is a message passing mechanism that is used for communication between different connectors that are connected with each other. It also acts as a communicator between various components of Amazon. It keeps all the different functional components together. This functionality helps different components to be loosely coupled, and provide an AWS architecture that is more failure resilient system.
6. Can I vertically scale an Amazon instance? How?
Yes. This is an incredible feature of AWS and cloud virtualization. Spin up a new larger instance than the one you are currently running. Pause that instance and detach the root ebs volume from this server and discard. Then stop your live instance, detach its root volume. Note down the unique device ID and attach that root volume to your new server. And then start it again. Voila, you have scaled vertically in-place!!
7. Explain Stopping, Starting, and Terminating an Amazon EC2 instance?
Stopping and Starting an instance: When an instance is stopped, the instance performs a normal shutdown and then transitions to a stopped state. All of its Amazon EBS volumes remain attached, and you can start the instance again at a later time. You are not charged for additional instance hours while the instance is in a stopped state.
Terminating an instance: 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. The instance itself is also deleted, and you can’t start the instance again at a later time.
8. What are the features of the Amazon EC2 service?
As the Amazon EC2 service is a cloud service so it has all the cloud features. Amazon EC2 provides the following features:
- Virtual computing environment (known as instances)
- Pre-configured templates for your instances (known as Amazon Machine Images – AMIs)
- Amazon Machine Images (AMIs) is a complete package that you need for your server (including the operating system and additional software)
- Amazon EC2 provides various configurations of CPU, memory, storage and networking capacity for your instances (known as instance type)
- Secure login information for your instances using key pairs (AWS stores the public key and you can store the private key in a secure place)
- Storage volumes of temporary data is deleted when you stop or terminate your instance (known as instance store volumes)
- Amazon EC2 provides persistent storage volumes (using Amazon Elastic Block Store – EBS)
- A firewall that enables you to specify the protocols, ports, and source IP ranges that can reach your instances using security groups
- StaticIP addresses for dynamic cloud computing (known as Elastic IP address)
- Amazon EC2 provides metadata (known as tags)
- Amazon EC2 provides virtual networks that are logically isolated from the rest of the AWS cloud, and that you can optionally connect to your own network (known as virtual private clouds – VPCs)
9. What is auto-scaling? How does it work?
Autoscaling is a feature of AWS which allows you to configure and automatically provision and spin up new instances without the need for your intervention. You do this by setting thresholds and metrics to monitor. When those thresholds are crossed, a new instance of your choosing will be spun up, configured, and rolled into the load balancer pool. Voila, you’ve scaled horizontally without any operator intervention!
10. When will you incur costs with an Elastic IP address (EIP)?
You are not charged, if only one Elastic IP address is attached with your running instance. But you do get charged in the following conditions:
- When you use more than one Elastic IPs with your instance.
- When your Elastic IP is attached to a stopped instance.
- When your Elastic IP is not attached to any instance.
11. How many buckets can you create in AWS by default?
By default, you can create upto 100 buckets in each of your AWS accounts.
12. What is the maximum retention period for SQS Messages?
14 days. After that all messages would have been lost.
13. What is the limit to the number of parameters or outputs in a template?
You can include up to 60 parameters and 60 outputs in a template
14. What are the various Route 53 routing policies?
The various Route 53 routing policies are as follows:-
a) Simple routing policy – Use for a single resource that performs a given function for your domain,for example,a web server that serves content for the abc.com website.
b) Failover routing policy – Use when you want to configure active-passive failover.
c) Geolocation routing policy – Use when you want to route traffic based on the location of your users.
d) Geoproximity routing policy – Use when you want to route traffic based on the location of your resources and, optionally shift traffic from resources in one location to resources in another.
e) Latency Routing Policy – Use when you have resources in multiple locations and you want to route traffic to the resource that provides the best latency.
f) Multivalue answer routing policy – Use when you want Route 53 to respond to DNS Queries with up to eight healthy records selected at random.
g) Weighted routing policy – Use to route traffic to multiple resources in proportions
15. Describe a SNS Notification by an example.
An example of the notification is shown below,here you can see different parts of a SNS message.
POST / HTTP/1.1
x-amz-sns-message-type: Notification
x-amz-sns-message-id: 22b80b92-fdea-42c2-8f9d-bdfb0c7bf324
x-amz-sns-topic-arn: arn:aws:sns:us-west-2:12348485:MyTopic:c7993-26c4-47e89
Content-Length: 773
Content-Type: text/plain; charset=UTF-8
Host: myhost.example.com
Connection: Keep-Alive
User-Agent: Amazon Simple Notification Service Agent
{
"Type" : "Notification",
"MessageId": "22bhfhfhf-fdea-4c2c-8ffgf-bjghfjgjg",
"TopicArn": "arn:aws:sns:us-west-2:12347575859:MyTopic",
"Subject": "My First Message",
"Message": "Hello World",
"Timestamp": "2012-05-02T00:54:06.655Z",
"SignatureVersion": "1",
"Signature": "EXAMPLEvGGHbgjGHJKJLKLbhjoEIRFFJFJFlfgsvhjnjbjJWONJAHefjdjlcl",
"SigningCertURL": "https://sns.us-west-2.amazonaws.com/SimpleNotificationService-f3443egedjk",
"UnsubscribeURL": "https://sns.us-west-2.amazonaws.com/?Action=Unsubscribe&Subscription"
}
16. What are the push notification platform currently aws supported?
Currently, the following push notifications platforms are supported:
a) Amazon Device Messaging(ADM)
b) Apple Push Notification Service(APNS)
c) Google Cloud Messaging(GCM)
d) Windows Push Notification Service(WNS) for Windows 8+ and Windows 8.1+
e) Microsoft Push Notification Service(MPNS) for Windows Phone 7+
f) Baidu Cloud Push for Android devices in China.
17. Explain what is T2 instances?
T2 instances are designed to provide moderate baseline performance and the capability to burst to higher performance as required by workload.
18. Mention what is the difference between Amazon S3 and EC2?
The difference between EC2 and Amazon S3 is that
EC2:-
a)It is a cloud web service used for hosting your application
b)It is like a huge computer machine which can run either Linux or Windows and can handle application like PHP, Python, Apache or any databases
S3:-
a)It is a data storage system where any amount of data can be stored
b)It has a REST interface and uses secure HMAC-SHA1 authentication keys
19. Explain can you vertically scale an Amazon instance? How?
Yes, you can vertically scale on Amazon instance. For that
a) Spin up a new larger instance than the one you are currently running
b) Pause that instance and detach the root webs volume from the server and discard
c) Then stop your live instance and detach its root volume
d) Note the unique device ID and attach that root volume to your new server
e) And start it again
20. Explain what is AMI?
AMI stands for Amazon Machine Image. It’s a template that provides the information(an operating system, an application server and applications) required to launch an instance, which is a copy of the AMI running as a virtual server in the cloud. You can launch instances from as many different AMIs as you need.
21. Explain what is S3?
S3 stands for Simple Storage Service. You can use S3 interface to store and retrieve any amount of data, at any time and from anywhere on the web. For S3, the payment model is “pay as you go”.
22. How can you send request to Amazon S3?
Amazon S3 is a REST service, you can send request by using the REST API or the AWS SDK wrapper libraries that wrap the underlying Amazon S3 REST API.
23. Difference between AWS SWF and AWS Step function?
The major difference between above two services is the coordination between stages (orchestration logic). In SWF this is handled by “Deciders”. There can be multiple deciders in a SWF workflow.
In Step Functions this is handled by the “State Definition” and there can be only one per workflow.
24. What are the languages supported for creating AWS Lambda function?
Following languages are supported for creating lambda function:-
a) C#
b) Go
c) Java
d) Node.js
e) Python
