☩ Walking in Light with Christ – Faith, Computing, Diary

While we were building a new machine that will serve as a Haproxy server proxy frontend to tunnel some traffic to a number of backends, 
came across weird oddity. The call requests sent to the haproxy and redirected to backend servers, were being written in the log twice.

Since we have two backend Application servers hat are serving the request, my first guess was this is caused by the fact haproxy
tries to connect to both nodes on each sent request, or that the double logging is caused by the rsyslogd doing something strange on each
received query. The rsyslog configuration configured to send via local6 facility to rsyslog is like that:

$ModLoad imudp
$UDPServerAddress 127.0.0.1
$UDPServerRun 514
#2022/02/02: HAProxy logs to local6, save the messages
local6.*                                                /var/log/haproxy.log

The haproxy basic global and defaults and frontend section config is like that:
 

global
    log          127.0.0.1 local6 debug
    chroot       /var/lib/haproxy
    pidfile      /run/haproxy.pid
    stats socket /var/lib/haproxy/haproxy.sock mode 0600 level admin
    maxconn      4000
    user         haproxy
    group        haproxy
    daemon

 

defaults
    mode        tcp
    log         global
#    option      dontlognull
#    option      httpclose
#    option      httplog
#    option      forwardfor
    option      redispatch
    option      log-health-checks
    timeout connect 10000 # default 10 second time out if a backend is not found
    timeout client 300000
    timeout server 300000
    maxconn     60000
    retries     3
 

listen FRONTEND1
        bind 10.71.80.5:63750
        mode tcp
        option tcplog
        log global
        log-format [%t] %ci:%cp %bi:%bp %b/%s:%sp %Tw/%Tc/%Tt %B %ts %ac/%fc/%bc/%sc/%rc %sq/%bq
        balance roundrobin
        timeout client 350000
        timeout server 350000
        timeout connect 35000
        server backend-host1 10.80.50.1:13750 weight 1 check port 15000
        server backend-host2 10.80.50.2:13750 weight 2 check port 15000

After quick research online on why this odd double logging of request ends in /var/log/haproxy.log it turns out this is caused by the 

log global  defined double under the defaults section as well as in the frontend itself, hence to resolve simply had to comment out the log global in Frontend, so it looks like so:

listen FRONTEND1
        bind 10.71.80.5:63750
        mode tcp
        option tcplog
  #      log global
        log-format [%t] %ci:%cp %bi:%bp %b/%s:%sp %Tw/%Tc/%Tt %B %ts %ac/%fc/%bc/%sc/%rc %sq/%bq
        balance roundrobin
        timeout client 350000
        timeout server 350000
        timeout connect 35000
        server backend-host1 10.80.50.1:13750 weight 1 check port 15000
        server backend-host2 10.80.50.2:13750 weight 2 check port 15000

Next just reloaded haproxy and one request started leaving only one trail inside haproxy.log as expected 🙂
 

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Tags: cfg, check, client, due, haproxy, option, port, requests, tcp, var

This entry was posted on Tuesday, March 8th, 2022 at 12:13 pm and is filed under Haproxy. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.