Child host becomes unreachable in redundant group when parent is unreachable

[jjuanino]

Describe the bug

Dear community,
unless I am misunderstanding something, redundant groups does not work as expected.
Consider the following setup:

   poc_grand_parent 
             |
             |
             | (classic dependency)
             |
             | 
       poc_parent_0                                     poc_parent_1
        \                                                /
          \        (redundant dependency)              /   
            \                                        / 
              \                                    /
                 \                               /
                    \                          /
                        \                 /
                             poc_child

• poc_parent_0 has a classical dependency with poc_grand_parent.
• poc_child has a redundant dependency with poc_parent_0 and poc_parent_1

The issue is as follows: when poc_grand_parent becomes down, poc_parent_0 becomes unreachable (as usual), but poc_child also, which is unexpected.

To Reproduce

Consider the following setup:

object Host "poc_grand_parent" { check_command = "dummy"; vars.dummy_state = 2; }
object Host "poc_parent_0" { check_command = "dummy"; vars.dummy_state = 0; }
object Host "poc_parent_1" { check_command = "dummy"; vars.dummy_state = 0; }
object Host "poc_child" { check_command = "dummy"; vars.dummy_state = 0;}

object Dependency "parent_0_to_grandparent" {
    child_host_name = "poc_parent_0"
    parent_host_name = "poc_grand_parent"
}

for (i in range(2)) {
    object Dependency "dep-" + i use (i) {
        child_host_name = "poc_child"
        parent_host_name = "poc_parent_" + i
        redundancy_group = "broken_red_deps"
    }
}

Expected behavior

The expected behavior is that poc_child host remains reachable despite of the state of poc_grand_parent.

Screenshots

Your Environment

Include as many relevant details about the environment you experienced the problem in

• Version used (icinga2 --version):

$ /usr/local/icinga2/sbin/icinga2 --version
icinga2 - The Icinga 2 network monitoring daemon (version: r2.14.2-1)

Copyright (c) 2012-2024 Icinga GmbH (https://icinga.com/)
License GPLv2+: GNU GPL version 2 or later <https://gnu.org/licenses/gpl2.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

System information:
  Platform: Red Hat Enterprise Linux
  Platform version: 8.9 (Ootpa)
  Kernel: Linux
  Kernel version: 4.18.0-513.11.1.el8_9.x86_64
  Architecture: x86_64

Build information:
  Compiler: GNU 8.5.0
  Build host: ol8-template.localdomain
  OpenSSL version: OpenSSL 1.1.1k  FIPS 25 Mar 2021

Application information:

General paths:
  Config directory: /usr/local/icinga2/etc/icinga2
  Data directory: /usr/local/icinga2/var/lib/icinga2
  Log directory: /usr/local/icinga2/var/log/icinga2
  Cache directory: /usr/local/icinga2/var/cache/icinga2
  Spool directory: /usr/local/icinga2/var/spool/icinga2
  Run directory: /usr/local/icinga2/var/run/icinga2

Old paths (deprecated):
  Installation root: /usr/local/icinga2
  Sysconf directory: /usr/local/icinga2/etc
  Run directory (base): /usr/local/icinga2/var/run
  Local state directory: /usr/local/icinga2/var

Internal paths:
  Package data directory: /usr/local/icinga2/share/icinga2
  State path: /usr/local/icinga2/var/lib/icinga2/icinga2.state
  Modified attributes path: /usr/local/icinga2/var/lib/icinga2/modified-attributes.conf
  Objects path: /usr/local/icinga2/var/cache/icinga2/icinga2.debug
  Vars path: /usr/local/icinga2/var/cache/icinga2/icinga2.vars
  PID path: /usr/local/icinga2/var/run/icinga2/icinga2.pid

• Operating System and version:

$ cat /etc/os-release
NAME="Red Hat Enterprise Linux"
VERSION="8.9 (Ootpa)"
ID="rhel"
ID_LIKE="fedora"
VERSION_ID="8.9"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Red Hat Enterprise Linux 8.9 (Ootpa)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:redhat:enterprise_linux:8::baseos"
HOME_URL="https://www.redhat.com/"
DOCUMENTATION_URL="https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8"
BUG_REPORT_URL="https://bugzilla.redhat.com/"

REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 8"
REDHAT_BUGZILLA_PRODUCT_VERSION=8.9
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="8.9"

• Enabled features (icinga2 feature list):

# icinga2 feature list
Disabled features: command compatlog debuglog elasticsearch gelf graphite ido-mysql ido-pgsql influxdb2 livestatus opentsdb perfdata statusdata syslog
Enabled features: api checker icingadb influxdb mainlog notification

• Icinga Web 2 version and modules (System - About):
  

[Al2Klimov]

Hello Jose!

Does just Web mis-indicate the reachability or the Icinga 2 API, too?

Best,
A/K

[jjuanino]

Hi Alexander,

in the icinga2 console I get the following (output snipped):

<1> => get_host("poc_child")
{
	__name = "poc_child"
	check_attempt = 1.000000
	check_command = "dummy"
	check_interval = 300.000000
	last_check_result = {
		active = true
		command = "dummy"
		exit_status = 0.000000
		output = "Check was successful."
		previous_hard_state = 99.000000
		vars_after = {
			attempt = 1.000000
			reachable = false    ◄◄◄◄◄◄◄◄◄◄◄◄◄◄◄◄
			state = 0.000000
			state_type = 1.000000
		}
		vars_before = {
			attempt = 1.000000
			reachable = true
			state = 0.000000
			state_type = 1.000000
		}
	}
	last_reachable = false   ◄◄◄◄◄◄◄◄◄◄◄◄◄◄◄◄
}

Best regards