unique-id-header logged twice ?

[Jakov Sosic]

Hi guys,

I have following setings in my haproxy:
defaults
    # populate X-Unique-ID header
    unique-id-format %{+X}o\ %ci:%cp_%fi:%fp_%Ts_%rt:%pid
    unique-id-header X-Unique-ID



Later I log it in Apache in custom log format:

LogFormat "%a %l %u [%{%d/%b/%Y:%T}t,%{msec_frac}t %{%z}t] \"%r\" %>s %b 
\"%{Referer}i\" \"%{User-Agent}i\" \"%{X-Unique-ID}i\"" combined_uniqueid


But, lately I've notice - very rarely but still happened, a request 
which logged two unique ids.

After verfying ips and ports, I conclude that first request has:

SRC: 192.168.50.200 [client_ip]
DST: 192.168.50.99  [haproxy_ip]

second one though, has:

SRC: 192.168.50.99  [haproxy_ip]
DST: 192.168.50.99  [haproxy_ip]


An example:

[Fri Aug 19 12:20:13.468461 2016] [-:error] [pid 9390] [client 
192.168.1.99:53393] [request_id: 
C0A801C8:DE3E_C0A80163:0050_573D9359_39BE5:6408, 
C0A80163:CBB9_C0A80163:0050_573D935C_39BE8:6408] .....


Any ideas what could have happened over here?