Apache Load Balancer in front of Apigee Nginx routers

[#1]

After setting up Apache LB in front of nginx routers, we get the following error upon accessing api:

 {"fault":{"faultstring":"Unable to identify proxy for host: default and url: \/oauth2\/access_token","detail":{"errorcode":"messaging.adaptors.http.flow.ApplicationNotFound"}}} 

[#2]

This indicates that Apache LB is not forwarding the expected host header. Edge router compares the Host header of the incoming request to the list of available host aliases as part of determining the API proxy that handles the request. To resolve this issue, you could set the host alias of the virtual host to be the same as that of the DNS name used in your apache configuration. For example: If your clients access api using the DNS name: "test.api.com" then configure the same as the host alias in Apigee virtualhost configuration. In Apache virtualhost configuration, please set the property : "ProxyPreserveHost On". This will ensure that Apache forwards the expected host header.

[#3]

Refer to Edge Install Guide for details: http://docs.apigee.com/private-cloud/latest/setting-virtual-host