CloudWatch Metrics for Troubleshooting ELB Instances
Question
A user has configured an ELB to distribute the traffic among multiple instances.
The user instances are facing some issues due to the back-end servers.
Which of the below mentioned CloudWatch metrics helps the user understand the issue with the instances?
Answers
Explanations
Click on the arrows to vote for the correct answer
A. B. C. D.Answer - D.
The Either HTTPCode_Backend_5XXfor the load balancer is caused by issues in the backend servers.
The different sort of errors are given below.
· HTTP 502: Bad Gateway.
· HTTP 503: Service Unavailable.
· HTTP 504: Gateway Timeout.
For more information on ELB errors visit the link:
http://docs.aws.amazon.com/elasticloadbalancing/latest/classic/ts-elb-http-errors.htmlThe correct answer is D. HTTPCode_Backend_5XX.
Explanation:
An Elastic Load Balancer (ELB) distributes incoming traffic across multiple instances, providing high availability and scalability for applications running in AWS. When an application running on an instance behind an ELB starts experiencing issues, it can impact the traffic flow, leading to errors and lower performance. CloudWatch is a monitoring service provided by AWS that collects and stores metrics for various AWS resources, including ELB.
CloudWatch provides several metrics related to the ELB, including HTTPCode_Backend_2XX, HTTPCode_Backend_3XX, HTTPCode_Backend_4XX, and HTTPCode_Backend_5XX. These metrics track the HTTP response codes generated by the back-end instances. HTTPCode_Backend_2XX tracks the number of HTTP response codes in the 2xx range (200-299) generated by the back-end instances, while HTTPCode_Backend_3XX tracks the number of codes in the 3xx range (300-399), HTTPCode_Backend_4XX tracks the number of codes in the 4xx range (400-499), and HTTPCode_Backend_5XX tracks the number of codes in the 5xx range (500-599).
In this scenario, the user is facing issues with the back-end servers, which means that the instances behind the ELB are not functioning correctly. The HTTP response codes generated by the instances can provide valuable insights into the nature of the issue. HTTPCode_Backend_5XX tracks the number of server error responses generated by the instances, indicating that the instances are experiencing internal errors. Therefore, monitoring this metric can help the user understand the issues with the instances and take corrective actions to resolve them.
In summary, CloudWatch metric HTTPCode_Backend_5XX helps the user understand the issues with the instances when they face issues due to back-end servers.
