EC2 Flashcards
You have deployed a database technology that has a synchronous replication mode to survive disasters in data centers. The database is therefore deployed on two EC2 instances in two Availability Zones. The database must be publicly available so you have deployed the EC2 instances in public subnets. The replication protocol currently uses the EC2 public IP addresses.
What can you do to decrease the replication cost?
Use the EC2 instances private IP for the replication. The source of the cost is that traffic between two EC2 instances is going over the public internet, thus incurring high costs. Here, the correct answer is to use Private IP, so that the network remains private, for a minimal cost.
Using Elastic IPs will not solve the problem as the traffic will still be going over the public internet.
What is a spot fleet?
A Spot Fleet is a set of Spot Instances and optionally On-Demand Instances that is launched to meet your target capacity
Spot instances are:
uses spare EC2 capacity
90% off on-demand instance
can be terminated with a 2-minute warning
What do spot blocks allow you to do?
request ec2 spot instances for 1 to 6 hours
True or False
Spot blocks are designed not to be interrupted and will run continuously for the duration you select (1 to 6 hours), independent of the Spot market price.
True
In this scenario, what is the best way to set permissions?
An application running on an EC2 instance needs to access a DynamoDB table in the same AWS account.
Set up an IAM service role with the appropriate permissions to allow access to the DynamoDB table.
Configure an instance profile to assign this IAM role to the EC2 instance
A Big Data analytics company is using a fleet of Amazon EC2 instances to ingest Internet-of-Things (IoT) data from various data sources. The data is in JSON format and ingestion rates can be as high as 1 MB/s. When an EC2 instance is restarted, the in-flight data is lost. The analytics team at the company wants to store as well as query the ingested data in near-real-time.
Why are Kinesis Data Stream and Kinesis Data Analytics by themselves not able to support his scenario?
They are not database themselves. Only transport tools.
The development team at a company manages a flexible nightly process which runs for 1 hour using Python. The process currently runs on the on-premises infrastructure and it needs to be migrated to AWS.
Which of the following options do you recommend as the MOST cost-effective solution?
Spot instance with spot block. not Lambda because job lasts longer than 15 minutes.
A development team has noticed that one of the EC2 instances has been incorrectly configured with the ‘DeleteOnTermination’ attribute set to True for its root EBS volume.
As a Solution’s Architect, can you suggest a way to disable this flag while the instance is still running?
Set the DeleteOnTermination value to False
Why would a cluster placement group work best for instances?
A company manages a High Performance Computing (HPC) application that needs to be deployed on EC2 instances. The application requires high levels of inter-node communications and high network traffic between the instances.
Cluster placement groups pack instances close together inside an Availability Zone. They are recommended when the majority of the network traffic is between the instances in the group. These are also recommended for applications that benefit from low network latency, high network throughput, or both.
A company is deploying a web application and it wants to ensure that only the web tier of the application is publicly accessible. To accomplish this, the engineering team has designed the VPC with a public subnet and a private subnet. The application will be hosted on several EC2 instances in an Auto Scaling group. The team also wants TLS termination to be offloaded from the EC2 instances.
In which subnet does the load balancer go in, and which subnet does the auto-scaling group go in?
load balancer - public subnet
auto scaling group - private subnet
What main features of Auto-Scaling Group?
1) instances that are treated as a logical grouping for the purposes of automatic scaling and management.
2) enables health check replacements and scaling policies
3) both maintaining the number of instances in an Auto Scaling group and automatic scaling
The systems administrator at a company wants to set up a highly available architecture for a bastion host solution.
Why won’t elastic IP address work?
Why not VPC endpoint?
Why network load balancer vs application load balancer?
elastic IP address won’t work because it can only be applied to a single instance at a time.
vpc endpoint does not offer high availability. it simply connects VPC to AWS services
network load balancer works on TCP (layer 4) whereas alb works on layer 7
A Big Data consulting company runs large distributed and replicated workloads on the on-premises data center. The company now wants to move these workloads to Amazon EC2 instances by using the placement groups feature and it wants to minimize correlated hardware failures.
Which placement group works best?
Multi-az
partition
spread
cluster
partition
A startup wants to create a highly available architecture for its multi-tier application. Currently, the startup manages a single EC2 instance along with a single RDS MySQL DB instance. The startup has hired you as an AWS Certified Solutions Architect Associate to build a solution that meets these requirements while minimizing the underlying infrastructure maintenance effort.
Why won’t one availability zone work in this scenario?
it doesn’t provide high availability. requires at least 2 AZs
