Active Agent hosts not showing in Host Availability widget

[PYarra]

Hi folks, I'm fairly new to Zabbix, so any pointers would be much appreciated.

I'm using Zabbix 6.2. I have 3 hosts defined. All 3 show up in the hosts list, however only 1 (localhost) in the Host Availability widget. I'm pretty sure this is because the other 2 are defined using only Active Agent checks - they aren't reachable from the Zabbix server, so they can't be polled by ping or passive agent checks.

Is there a way to get these Active Agent hosts to show up in the Host Availability widget?

[Hamardaban]

https://www.zabbix.com/documentation/current/en/manual/web_interface/frontend_sections/data_collection/hosts#reading-host-availability

Active check availability
Since Zabbix 6.2 active checks also affect host availability, if there is at least one enabled active check on the host. To determine active check availability heartbeat messages are sent in the agent active check thread. The frequency of the heartbeat messages is set by the HeartbeatFrequency parameter in Zabbix agent and agent 2 configurations (60 seconds by default, 0-3600 range). Active checks are considered unavailable when the active check heartbeat is older than 2 x HeartbeatFrequency seconds.
Note that if Zabbix agents older than 6.2.x are used, they are not sending any active check heartbeats, so the availability of their hosts will remain unknown.
Active agent availability is counted towards the total Zabbix agent availability in the same way as a passive interface is (for example, if a passive interface is available, while the active checks are unknown, the total agent availability is set to gray(unknown)).

[PYarra]

Thanks for the response, Hamardaban.

Note that while these agents with Active checks are showing as available in the host list (see first screenshot) they are not showing up in the Host Availability widget. So there's no issue with them being counted as available... but they don't show up (not even as unavailable) in the Host Availability widget (see second screenshot). That's the crux of my question.

Any ideas why this might be the case?

[Hamardaban]

Look at the widget settings - which host groups are shown? Which interfaces are shown?

[PYarra]

No host groups are selected, so I assume this means all hosts are displayed (no filtering) but only 1 host shows in the Host Availability widget. If I select the host group to which the 2 servers that aren't showing up belong to, it shows 0 hosts.

[Hamardaban]

In the picture with the list of hosts, I do not see interfaces for "problematic" hosts. Show the settings of one of them.

[PYarra]

There are no interfaces to add, because they're not reachable to be polled - they're only doing active checks.

[cyber]

That may be the issue... no interface, no numbers... Might aswell be bug in widget, as having an interface is not mandatory any more...

[PYarra]

That may be the issue... no interface, no numbers... Might aswell be bug in widget, as having an interface is not mandatory any more...

Yeah, that's my suspicion too. Everything I've read indicates that a host is considered available if the active agent heartbeat keeps coming in. They just don't seem to show up in this widget (which is a pity because it's the first thing new users see in the dashboard)

[cyber]

Well, widget works based on "selected interfaces"... If no interface, then you cannot select it and it wont show up.. So, you can say, works as intended. But in reality, needs update to reflect currently possible options. You can submit bugreport to https://support.zabbix.com/projects/ZBX/issues

[Arctica]

Hi,
I am also completely new to Zabbix but I am 100% impressed with what the solution can do and will implement it where I am responsible for a quite large network.
I start with setting up Zabbix at my home network to learn more before I deploy it at work. I have installed V6.4.1 and I have added some Windows 2022 Servers, they are on the same local subnet, I do not have the firewall turned on and have installed the active agent on the servers.
ZBX is green for the hosts and I get all the collections of data for the template. But just as other reports in this thread they are not even shown in the "Host availability" widget. My beginners question is simple: How do I make the Windows servers with active agent visible? I understand what cyber says in the post here above, that the widget works by adding an interface, but what interface should I add? I tried adding "Agent" and the IP of the Windows Server and port 10050 but the only result by doing this is that ZBX goes grey and the interface says "unknown". Am I missing something obvious?

[Arctica]

I understand that the opinion is that this is "intended behaviour" and that machines that have the "Active Zabbix Agent" can't be added to the host availability widget.
But let me re-phrase my question then: If I have a Windows server, how can I add it to the widget so I can see if it is available or not? Should I use SNMP or IPMI as well as the active agent for these servers? Should I not use the active agent but rather the passive agent? If someone has solved it in an alternative way I would love to know how.