Hey, we plan create the same configuration in our environment. Do you have any more comments about this – maybe some pros and cons?

Ingus

We run this configuration on a number of boxes, which works fairly well providing the boxes do not become completely saturated.

A few tips:

* Avoid putting on “iface eth0” if you need to restart the interface its very easy to mess up ifdown eth0 && ifup eth0.
* We have since changed the skew to avoid our monitoring of ucarp tripping…

iface eth0 inet static
        ucarp-advskew 0
        ucarp-advbase 2 
        ....
iface eth0:ucarp inet static
iface eth0:1 inet static
        ucarp-advskew 0
        ucarp-advbase 3
        ....
iface eth0:1:ucarp inet static
iface eth0:2 inet static
        ucarp-advskew 0
        ucarp-advbase 3
        ....
iface eth0:2:ucarp inet static
iface eth0:3 inet static
        ucarp-advskew 0
        ucarp-advbase 3
        ....

We monitor the ucarp instances with mon.

#!/bin/bash

if [ $# -ne 2 ] ; then 
  echo "Invalid usage, should be `basename $0`  "; 
  exit 11; 
fi;

pgrep -f "/usr/sbin/ucarp -i ${1} .*${2} " > /dev/null;
if [ $? -ne 0 ] ; then
  echo "Missing ucarp process, VIP: $2, interface $1"; 
  exit 1;
fi;

exit 0;

And HA Proxy with

#!/bin/bash

logfile="/var/log/mon/haproxy.log"

killucarp() {
  sudo /etc/network/local/clean-vip.sh $1;
}

haproxy_status()
{
        # try for three times before raising an alarm
        retry=0;
        statusok=0;
        # PID file
        while [ $retry -lt 3 ]; do
          if [ -f $2 ] ; then
            statusok=1; 
            break; 
          fi; 
          echo "No PID file, retry $retry";
          let retry=$retry+1; 
          sleep 1;
        done;
       
        if [ $statusok -ne 1 ] ; then
          echo "HAProxy $2 not running (no PID file)"; 
          killucarp "$1" "$2";
          exit 3;
        fi; 

        retry=0; 
        statusok=0;
      
        while [ $retry -lt 3 ] ; do
          pid=$(cat $2); 
          if [ "$pid" -gt 0 2> /dev/null ] ; then 
            if ps --no-headers p $pid | grep haproxy | grep -q "$2"; then
               statusok=1;
               break;
            else 
               echo "Process $pid does not exist or doesnt match definition $2, retry $retry"; 
               echo "--- `date` --- Process $pid does not exist or doesnt match definition $2, retry $retry" >> $logfile;  
               ps axf >> $logfile;
            fi; 
          else 
             echo "PID file invalid, retry $retry"; 
          fi; 
          let retry=$retry+1; 
          sleep 1;
        done; 
  
        if [ $statusok -ne 1 ] ; then
          echo "HAProxy $2 not running (no PID file)"; 
          killucarp "$1" "$2";
          exit 3;
        fi; 
         
       # echo "HaProxy running";
       exit 0;
}


if [ $# -ne 2 ] ; then
  echo "Usage : $(basename $0) [ IP ] [ pid file ]";
  exit 1;
fi;

if ! ( ip addr show | grep "inet $1" -q ) ; then
  # no ip , nothing to worry about
  # echo "no ip";
  exit 0; 
fi;

haproxy_status $1 $2;