SOA-C02 Premium Exam Questions

Evictions in Amazon ElastiCache for Memcached occur when the cache runs out of available memory and needs to remove existing data to store new data. To reduce evictions, you can either add more nodes to the cluster or increase the size of the individual nodes.

Add an Additional Node:

Open the Amazon ElastiCache console at Amazon ElastiCache Console.

Select your Memcached cluster and choose Modify.

Increase the number of nodes in the cluster to add more memory capacity.

Apply the changes to scale out the cluster.

Increase the Individual Node Size:

Open the Amazon ElastiCache console and select your Memcached cluster.

Choose Modify and change the node type to a larger instance size with more memory.

Apply the changes to scale up the cluster.

Both actions will provide additional memory capacity, reducing the likelihood of evictions due to insufficient memory.

References:

Scaling ElastiCache for Memcached

Amazon ElastiCache for Memcached User Guide

To design a high-traffic static website that is highly available and provides low latency globally, you can use Amazon S3, CloudFront, and Route 53. This solution leverages the global edge locations of CloudFront to deliver content with low latency.

Create an Amazon S3 Bucket:

Open the S3 console at Amazon S3 Console.

Create a new bucket and upload your website content.

Configure S3 for Static Website Hosting:

Go to the Properties tab of your bucket.

Enable Static website hosting and set the index document (e.g., index.html).

Create a CloudFront Distribution:

Open the CloudFront console at Amazon CloudFront Console.

Create a new distribution and set the S3 bucket as the origin.

Configure distribution settings, including caching behaviors and SSL/TLS settings.

Create Route 53 Alias Record:

Open the Route 53 console at Amazon Route 53 Console.

Select the hosted zone for your domain.

Create a new record set, choose ALIAS as the record type, and point it to the CloudFront distribution.

References:

Amazon S3 Static Website Hosting

Creating a CloudFront Distribution

Routing Traffic to a CloudFront Distribution

For a Lambda function in Account A to access an S3 bucket in Account B, the correct IAM roles setup includes:

A: In Account A, create a Lambda execution role that has permissions to assume another role in Account B. In Account B, create a role with permissions to access the S3 bucket and trust the Lambda execution role from Account A to assume it. This configuration allows the Lambda function to assume the cross-account role and access the S3 bucket as needed, maintaining security and proper access control. AWS documentation provides more details on setting up cross-account roles for Lambda access AWS Lambda Permissions.

To reduce latency in data transfer among EC2 instances, especially in high-performance computing (HPC) applications or applications requiring low network latency, using a placement group is the best approach:

Understanding Placement Groups:

A placement group in Amazon EC2 is a logical grouping of instances within a single Availability Zone. Using placement groups, you can achieve low-latency network performance necessary for tightly coupled node-to-node communication.

Types of Placement Groups:

Cluster Placement Group: Instances are physically located close together in the same Availability Zone to provide low-latency network performance.

Partition Placement Group: Instances are divided into logical segments called partitions, reducing the likelihood of simultaneous failures.

Spread Placement Group: Instances are placed on distinct underlying hardware to reduce correlated failures.

Creating and Using a Placement Group:

You can create a placement group using the AWS Management Console, AWS CLI, or AWS SDKs.

When launching instances, specify the placement group to ensure they are launched within the same group.

aws ec2 create-placement-group --group-name my-placement-group --strategy cluster

aws ec2 run-instances --image-id ami-12345678 --count 4 --instance-type c5.large --placement GroupName=my-placement-group

Relocating Existing Instances:

Stop the instances, modify the placement group settings, and then restart them. Note that not all instance types are supported within placement groups, so check the documentation for compatibility.

References:

Placement Groups

Cluster Instances for Low-Latency