AWS Interview Questions
AWS stands for Amazon Web Service. AWS is the collection of remote computing services also known as cloud computing platform.
Following are the key components of AWS:
- AWS Route 53: It is a highly available and scalable cloud Domain Name System (DNS) web service.
- Simple E-mail Service (SES): It is cloud-based email sending service which allows sending e-mail using RESTful API call or via regular SMTP.
- Identity and Access Management: It provides enhanced security and identity management for your AWS account.
- Simple Storage Service (S3): It is most widely used aws storage service.
- Elastic Compute Cloud (EC2): It provides on-demand computing resources for hosting applications. It is very useful in case of unpredictable workloads.
- Elastic Block Store (EBS): It provides persistent storage volumes that attach to EC2 to allow you to persist data past the lifespan of a single EC2.
- CloudWatch: It monitors AWS resources, one can set a notification alarm in case of trouble.
In AWS, S3 stands for Simple Storage Service.
You can use S3 to store and retrieve any amount of data, at any time and from anywhere on the web.
AMI stands for Amazon Machine Image.
AMI provides the information required to launch an instance.
In AWS, from a single AMI, you can launch multiple Instances.
An AMI includes the following things
- A Template for the root volume of the instance.
- Launch permissions that controls which AWS accounts can use the AMI to launch instances
- A block device mapping that determines the volumes to attach to the instance when it is launched
|It is a cloud web service used for hosting your application||It is a data storage system where any amount of data can be stored|
|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||It has a REST interface and uses secure HMAC-SHA1 authentication keys|
By default, you can create upto 100 buckets in each of your AWS accounts.
There are two types of scaling
- Horizontal Scaling
- Vertical Scaling
Horizontal scaling means that you scale your server by adding more machines into your pool of resources.
Horizontal scaling can be achieved with the help of clustering, load balancing
Vertical scaling means that you scale up your server by adding more power (CPU, RAM) to an existing machine.
You should follow the following steps
- Use AWS identity and access management to control access to your AWS resources
- Restrict access by allowing only trusted hosts or networks to access ports on your instance
- Review the rules in your security groups regularly
- Only open up permissions that your require
- Disable password-based login, for instance, launched from your AMI
The buffer is used to make the system more robust to manage traffic or load by synchronizing different component.Usually, components receive and process the requests in an unbalanced way, With the help of buffer, the components will be balanced and will work at the same speed to provide faster services.
The possible connection errors one might encounter while connecting instances are
- Connection timed out
- User key not recognized by the server
- Host key not found, permission denied
- Unprotected private key file
- Server refused our key or No supported authentication method available
- Error using MindTerm on Safari Browser
- Error using Mac OS X RDP Client
RDS stands for Relational Database Service is a managed SQL Database service that makes it easier to set up, operate, and scale a relational database on the cloud.