Answer - A and C.
You need to have the daemon service running on the EC2 Instance.
And a role needs to be attached to the EC2 Instance.
Running the X-Ray Daemon on Amazon EC2
You can run the X-Ray daemon on the following operating systems on Amazon EC2.
Amazon Linux.
Ubuntu.
Windows Server (2012 R2 and newer)
Use an instance profile to grant the daemon permission to upload trace data to X-Ray.
For more information, see Giving the Daemon Permission to Send Data to X-Ray.
Option B is incorrect since the agent can be installed on different types of instances.
Option D is incorrect since the traces need to be sent to the X-Ray service.
For more information on the X-Ray daemon service, please refer to the below URL-
https://docs.aws.amazon.com/xray/latest/devguide/xray-daemon-ec2.html
The X-Ray service is an AWS service that helps developers analyze and debug distributed applications, such as those that use EC2 instances and DynamoDB. The service provides an end-to-end view of requests as they travel through an application and enables developers to identify performance bottlenecks and errors.
In this scenario, the application deployed on an EC2 instance is experiencing performance issues, and the developer has decided to use the X-Ray service to debug these issues. However, they are unable to see the trails in the X-Ray service, which indicates that there may be an underlying issue preventing the service from functioning properly.
Let's review the given options to understand what could be causing the problem:
A. The X-Ray daemon is not installed on the EC2 Instance.
The X-Ray daemon is a software component that runs on EC2 instances and collects data about requests that pass through the application. If the X-Ray daemon is not installed on the EC2 instance running the application, then the X-Ray service will not receive any data about the application's performance. This could be a possible reason why the trails are not visible in the X-Ray service.
B. The right AMI is not chosen for the EC2 Instance.
An Amazon Machine Image (AMI) is a pre-configured virtual machine image that is used to create EC2 instances. If the AMI used to create the EC2 instance does not support the X-Ray daemon, then it will not be possible to collect performance data and send it to the X-Ray service. This could be another possible reason why the trails are not visible in the X-Ray service.
C. Ensure that the IAM Role attached to the Instance has permission to upload data onto X-Ray.
The IAM Role attached to the EC2 instance determines what permissions the instance has to access AWS resources, including the X-Ray service. If the IAM Role does not have permission to upload data onto the X-Ray service, then it will not be possible to send performance data to the service. This could be another possible reason why the trails are not visible in the X-Ray service.
D. Ensure that the IAM Role attached to the Instance has permission to upload data onto Cloudwatch.
Cloudwatch is another AWS service that is often used to monitor and debug applications. However, it is not directly related to the X-Ray service. If the IAM Role attached to the EC2 instance does not have permission to upload data onto Cloudwatch, then it will not be possible to send performance data to Cloudwatch, but this will not directly impact the ability to see trails in the X-Ray service.
In conclusion, options A and C could be the underlying issues that are preventing the trails from being visible in the X-Ray service. It is important to ensure that the X-Ray daemon is installed on the EC2 instance, and that the IAM Role attached to the instance has permission to upload data onto the X-Ray service.
