When an incoming connection fails due to an SSL handshake or an invalid PROXY protocol header, haproxy will log the event using a shorter, fixed line format.
By default, logs are emitted at the LOG_INFO level, unless the option “log-separate-errors” is set in the backend, in which case the LOG_ERR level will be used. Connections on which no data are exchanged (eg: probes) are not logged if the “dontlognull” option is set.
The Error log format looks like this :
>>> Dec 3 18:27:14 localhost haproxy: 127.0.0.1:56059 [03/Dec/2012:17:35:10.380] frt/f1: Connection error during SSL handshake
|Field||Format||Extract from the example above|
|1||process_name '[' pid ']:'||haproxy:|
|2||client_ip ':' client_port||127.0.0.1:56059|
|3||'[' accept_date ']'||[03/Dec/2012:17:35:10.380]|
|4||frontend_name "/" bind_name ":"||frt/f1:|
|5||message||Connection error during SSL handshake|
These fields just provide minimal information to help debugging connection failures.