AWS Technical Essentials

What is the AWS term for a physically distinct group of data centers in a Region?

• Availability Zone

• Region

• Edge Location

• Data Center

Answer explanation

Availability Zones are distinct locations within an AWS Region that are engineered to be isolated from failures in other Availability Zones. They provide inexpensive, low-latency network connectivity to other Availability Zones in the same AWS Region. Each region is completely independent.

AWS has more Regions than edge locations.

• True

• False

Answer explanation

AWS has 80 Availability Zones across 25 geographic regions, with plans to launch 15 more Availability Zones and five more AWS Regions in Australia, India, Indonesia, Spain, and Switzerland.

https://aws.amazon.com/about-aws/global-infrastructure/?p=ngi&loc=0

AWS owns and maintains the infrastructure required for application services. Customers provision and use them as needed.

• True

• False

Which AWS service would help support a web application by hosting static assets and storing user uploaded images and video off-instance?

Answer explanation

The AWS Solutions site lists many of the ways you can use Amazon S3. The following list summarizes some of those ways.

Backup and storage – Provide data backup and storage services for others.

Application hosting – Provide services that deploy, install, and manage web applications.

Media hosting – Build a redundant, scalable, and highly available infrastructure that hosts video, photo, or music uploads and downloads.

Software delivery – Host your software applications that customers can download.

What acts as an additional layer of security at the subnet level in an Amazon VPC?

• Network ACLs

• Security Group

• Network Rules

Answer explanation

A network access control list (ACL) is an optional layer of security for your VPC that acts as a firewall for controlling traffic in and out of one or more subnets.

A web application must read/write an Amazon DynamoDB table and an Amazon S3 bucket. This operation requires AWS credentials and authorization to use AWS services. What IAM entity should be used?

• User

• Group

• Role

• Policy

Answer explanation

An IAM role is an IAM identity that you can create in your account that has specific permissions. An IAM role is similar to an IAM user, in that it is an AWS identity with permission policies that determine what the identity can and cannot do in AWS. However, instead of being uniquely associated with one person, a role is intended to be assumable by anyone who needs it. Also, a role does not have standard long-term credentials such as a password or access keys associated with it. Instead, when you assume a role, it provides you with temporary security credentials for your role session.

Amazon DynamoDB allows customers to store any amount of data with no limits.

• True

• False

Answer explanation

The length of a Binary is constrained by the maximum item size of 400 KB.

Table SizeThere is no practical limit on a table's size. Tables are unconstrained in terms of the number of items or the number of bytes.

AWS Auto Scaling helps customers safeguard that they have the correct number of Amazon EC2 instances available to handle the load for their applications.

• True

• False

Answer explanation

An Auto Scaling group starts by launching enough instances to meet its desired capacity. It maintains this number of instances by performing periodic health checks on the instances in the group. The Auto Scaling group continues to maintain a fixed number of instances even if an instance becomes unhealthy. If an instance becomes unhealthy, the group terminates the unhealthy instance and launches another instance to replace it. For more information, see Health checks for Auto Scaling instances.

A customer has an application composed of individual services. They must route a request to a service based on the content of the request. Which type of load balancer should they use?

• Network Load Balancer

• Application Load Balancer

• Traffic Load Balancer

Answer explanation

Elastic Load Balancing automatically distributes your incoming traffic across multiple targets, such as EC2 instances, containers, and IP addresses, in one or more Availability Zones. It monitors the health of its registered targets, and routes traffic only to the healthy targets. Elastic Load Balancing scales your load balancer as your incoming traffic changes over time. It can automatically scale to the vast majority of workloads.

Which AWS service serves as a best practice and recommendation engine?