CLOUD COMPUTING
AUTOSCALING
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
The ELB instance has stopped working.
|
|
|
The URL for the app has passed its expiration date.
|
|
|
The application running on the EC2 instance is giving the 504 error because it has exceeded its response time limit.
|
|
|
The application is unresponsive, so the ELB instance displays the 504 error.
|
Detailed explanation-1: -HTTP 504: Gateway timeout Description: Indicates that the load balancer closed a connection because a request did not complete within the idle timeout period. Cause 1: The application takes longer to respond than the configured idle timeout. Solution 1: Monitor the HTTPCode ELB 5XX and Latency metrics.
Detailed explanation-2: -When the backend instance closes a TCP connection to the load balancer before it reaches its idle timeout value, an HTTP 504 error might display. To resolve this, activate keep-alive settings on your backend instances, and then set the keep-alive timeout to a value greater than the load balancer’s idle timeout.
Detailed explanation-3: -If an instance fails these health checks, it is marked unhealthy and is terminated while Amazon EC2 Auto Scaling launches a new replacement instance.
Detailed explanation-4: -The 504 (Gateway Timeout) status code indicates that the server, while acting as a gateway or proxy, did not receive a timely response from an upstream server it needed to access in order to complete the request. The error may be a temporary occurrence due to too much traffic toward the server or site.