This section describes the procedure to generate a custom error page with application-specific content.

Currently, NSX Advanced Load Balancer can generate custom responses from policy, DataScript, or a POOL_DOWN action. Other than this, there are cases where we cannot communicate with a back-end server (for instance, in case of a 502 error), where we respond to the client with a hard-coded page (non-custom). Customers occasionally prefer to generate their custom error page so that it doesn’t have NSX Advanced Load Balancer on the page but rather some application-specific message.

How it Works

NSX Advanced Load Balancer supports a new DataScript event named RESP_FAILED that triggers when any error/timeout happens till a valid response header is received from the server and forwarded to the client.

For instance:

  • TCP/SSL connect/handshake to server fails

  • Request proxy/send to server times out

  • No response or partial response headers or bad response headers from the server

  • The server resets connection while the NSX Advanced Load Balancer SE is waiting for the server to respond

A DataScript attached to the RESP_FAILED event is executed. Example functions exposed to the script are avi.http.response(), avi.http.redirect(), and (the newly created) avi.http.internal_status(). The user can use these to customize responses for the different types of failures, log the reason in NSX Advanced Load Balancer logs, etc. For more information, see

See also,