HAProxy ALOHA Documentation 15.5


When load balancing UDP-based services via the LB Layer4 tab, you can health check your servers by pinging them with the Internet Control Message Protocol (ICMP) to see if they're up. An ICMP ping sends an echo request packet to the server and then waits for a reply.

Enable ICMP ping

When you set up ICMP health checks, HAProxy ALOHA regularly tries to send the server a ping request. If the server does not return a response, the health check fails.

Check the availability of two Syslog servers.

director syslog_servers UDP
  balance roundrobin                      # load balancing algorithm
  mode gateway                            # forwarding mode

  option icmpcheck
  check interval 5s timeout 1s            # advanced check parameters
  server syslog1 check
  server syslog2 check
  1. Select the LB Layer4 tab.

  2. Add a check parameter to each server line for which you would like to enable health checking.

  3. Add option icmpcheck in the same section. It take no arguments.

  4. Add the line check to the section to configure other options. It uses the following syntax:

    check { [timeout <seconds>] [interval <seconds>] [source <ip>] [port <port>]
            [rise <count>] [fall <count>] [inhibit] }

    timeout <seconds>

    Period after which an attempt without a response from the server is considered as failed (default: half of interval)

    interval <seconds>

    Interval between two checks, in seconds (default: 10 seconds)

    source <ip>

    Source IP to use when performing the check

    port <port>

    Forces the destination port (default: real server port, if it exists)

    rise <count>

    A server will be considered as operational after <count> consecutive successful health checks. The default is 1.

    fall <count

    A server will be considered as dead after <count> consecutive unsuccessful health checks. The default is 1.


    If a server is down, its weight is passed to 0 but not deleted. Established connection are not broken but new connections are dispatched on the other servers.

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