Amazon Web Services Updated SOA-C02 Exam Questions and Answers by ayyub

To route traffic based on the URL path during a transition period where both an EC2-based legacy application and a new AWS Lambda function are in use:

Use of Application Load Balancer (ALB): ALBs support advanced request routing based on the URL path, among other criteria. This capability allows the ALB to evaluate the URL path of incoming requests and route them appropriately to either the legacy EC2 instances or the Lambda function.

Path-Based Routing Rules: Configure the ALB with rules that specify which URL paths should be directed to the EC2 instances and which should be routed to the Lambda function. For example, requests to /legacy/* might go to the EC2 instances, while /new/* could be directed to the Lambda function.

Integration with Lambda: ALBs can directly invoke Lambda functions in response to HTTP requests, making them ideal for scenarios where both server-based and serverless components are used in tandem.

This setup not only facilitates a smooth transition by enabling simultaneous operation of both components but also leverages the native capabilities of ALBs to manage traffic based on application requirements effectively.

Increasing DB Instance Size:

Increasing the instance size provides more CPU and memory resources, which can help handle higher loads.

Steps:

Go to the AWS Management Console.

Navigate to RDS and select the DB instance.

Modify the instance to increase its size.

Apply the changes during the next maintenance window or immediately if it is a critical issue.

Monitoring Performance:

After resizing, monitor the instance during the next report run to ensure that it handles the load effectively.

Modifying an Amazon RDS DB Instance

To efficiently find out how often the AWS Lambda function has failed in the last 7 days, use Amazon CloudWatch Logs Insights.

Access CloudWatch Logs Insights:

Navigate to the CloudWatch console.

Select "Logs Insights" from the navigation pane.

In AWS, there are default limits (also known as quotas) for the number of various resources that can be created in an account. One of these limits is the number of Virtual Private Clouds (VPCs) that can be created in a single AWS account within a Region. The default limit for the number of VPCs per account per Region is typically 5.

If an organization is running multiple applications, each requiring a new VPC, it is possible to reach this limit, causing subsequent CloudFormation stack deployments that attempt to create additional VPCs to fail.

Check VPC Limits:

To verify the current limit and usage of VPCs in your account, you can use the AWS Service Quotas console.

Open the Service Quotas console at Service Quotas Console.

Navigate to AWS services and select Amazon VPC.

Check the VPCs per Region quota to see the limit and how many VPCs are currently in use.

Requesting a Quota Increase:

If the default limit is reached, you can request a quota increase.

In the Service Quotas console, select the quota and choose Request quota increase.

Fill in the required information and submit the request. AWS typically reviews and approves these requests, but it may take some time.

CloudFormation Stack Failure:

When a CloudFormation stack fails due to reaching the VPC limit, the error message will indicate the issue related to the quota being exceeded.

You can view the specific error in the CloudFormation console under the Events tab of the stack.

Preventative Measures:

To avoid this issue, monitor resource usage and limits regularly.

Consolidate applications within fewer VPCs if possible, using subnets and security groups to isolate resources.

Amazon VPC Quotas

Service Quotas for VPC

Requesting a Quota Increase