HAProxy Enterprise Documentation 2.5r1
Logging Comments on Failure
comment directive to define a message that will be reported in the logs if the rule that follows the directive fails.
Define a message indicating a ping test has failed:
option tcp-check tcp-check comment PING\ phase tcp-check send PING\r\n
You can also include the
comment definition in
Define a message indicating a matching HTTP string was not received:
tcp-check expect rstring HTTP/1\..\ (2..|3..) comment check\ HTTP\ response
For complete details, see http-check comment.