Check_mk service monitoring returns (null)

[webhelp (Alejandro Delgado)]

Hello,

We upgraded our RAW check_mk installations today to version 2.1 from 2.0.
Since then we have been receiving (null) in the summery of the Check_MK service on some of the hosts, the ones that don’t have the agent installed.
Those hosts are configured with “No API integrations, no CheckMk agent”, or with “API integrations if configured, else Checkmk agent”

Has anyone else encountered this?

How could solve this issue?

Thanks.

Best Regards,

[MarkP (Mark)]

Same here, after upgrade to 2.1 we see CheckMK service on status null.
Hopefully someone knows a solution. It seems to happen on hosts using snmp connection.

[mana (Manfred)]

Same for me, I recently upgraded to 2.1.0p20 and also have this behavior. In my case with SNMP-printers, that have a rule for “Always assume host to be up”. And additionally with some Linux systems where I can’t install an agent on, ping would be enough for me.
Has this already been confirmed a bug or are we doing some misconfiguration?

[lars.getwan (Lars)]

Usually, the service “Check_MK” shouldn’t appear at all if you have “No API Integration/No CheckMK Agent” and “No SNMP” selected. In that case, and if there are no other active checks, either, the “PING” service is shown, solely.
@mana: Can you please share a “cmk -D ” output? Carefully check if the output contains any sensitive data before pasting.

[mana (Manfred)]

Hello Lars,
thanks for your answer. I tested again with one of the linux systems:
I noticed, that in the GUI (WATO) I have configured:
“No API integrations, no CheckMK agent” and “No SNMP”.
When I run “cmk -D” on the CLI, I get the following output:

bitdefender-sva-srlsrv
Addresses:              172.16.0.xxx
Tags:                   [Container:container_no], [address_family:ip-v4-only], [agent:no-agent], [criticality:prod], [database:db_no], [ip-v4:ip-v4], [location:LG], [mail:mail_no], [networking:lan], [os:lnx], [piggyback:auto-piggyback], [ping:ping], [site:sitename], [snmp_ds:no-snmp], [tcp:tcp], [ts:ts_no], [vm:vm_no], [web:web_no]
Labels:                 [cmk/site:sitename]
Host groups:            LG, linux
Contact groups:         check-mk-notify, admins
Agent mode:             Normal Checkmk agent, or special agent if configured
Type of agent:
  TCP: 172.16.0.xxx:6556
  Process piggyback data from /omd/sites/sitename/tmp/check_mk/piggyback/bitdefender-sva-srlsrv
Services:
  checktype item params description groups
  --------- ---- ------ ----------- ------

I tried to delete the host in WATO. Afterwards, I got this CLI output:

~$ cmk -D bitdefender-sva-srlsrv

bitdefender-sva-srlsrv
Addresses:              172.16.0.xxx
Tags:                   [address_family:ip-v4-only], [agent:cmk-agent], [criticality:prod], [networking:lan], [piggyback:auto-piggyback], [site:sitename], [snmp_ds:no-snmp]
Labels:                 [cmk/site:sitename]
Host groups:            check_mk
Contact groups:         check-mk-notify
Agent mode:             No agent
Type of agent:
  Process piggyback data from /omd/sites/sitename/tmp/check_mk/piggyback/bitdefender-sva-srlsrv
  PING only
Services:
  checktype item params description groups
  --------- ---- ------ ----------- ------

So somehow the host seems to still exist with its IP address, although I had deleted it.

Do you have any ideas on that?

[lars.getwan (Lars)]

Hi @mana,

From the first cmk -D call, I can see that the “Ping only” was somehow not true for thus host. Maybe, there were leftovers in the ~/var/check_mk/autochecks/ bitdefender-sva-srlsrv.mk file?
After deleting the host, the cmk -D shows the typical behavior: If the name of the host is DNS resolvable, the correct IP is shown (try “cmk -D forum.checkmk.com”), and “no agent”, “no-snmp” and “PING only” are shown. This is typical for hosts that don’t exist in the CMK site.
If you – again – create this host with “no agent” & “no-snmp”, what will the “cmk -D” show afterwards?

Best regards
Lars

[mana (Manfred)]

Hi @lars.getwan ,
thanks for the hint, I found my problem. I had set a tag “OS linux” for those systems, and that tag had included the CheckMK-service… I removed that tag → working as expected, PING
Thanks so much for your help!
Mana