Shortly after activating an agent or relay, the following error appears:
An error occurred in the Deep Security Manager to Deep Security Agent/Appliance protocol: NoHttpResponseException: The server [Load Balancer IP] failed to respond.
In Amazon Web Service (AWS), the load balancer's default idle timeout setting is 60 seconds. This default value needs to be increased. Increase the idle timeout (e.g. 600 seconds) to avoid getting the error.
For the complete procedure on how to increase the timeout value, refer to this Amazon Document: Configure the Idle Connection Timeout for Your Classic Load Balancer.