Zabbix Agent ping not working

[monitor-it443]

I use zabbix Server 6.4.11 on a linux docker environment and I want to monitor if a windows Host is online ( agent.ping )

I wrote the following trigger:

nodata(/myHostname/agent.ping,1)=1

with a Severity of "average"

Now I stop the zabbix agent on my win 10 Host with zabbix_agentd Win64 (service) (Zabbix) 6.4.6
And I get the trigger

But when I start the agent again I get periodically agent not running The Error is always like 1 or 2 minutes and then closes itself for like 1 minute and starts again.

The zabbix host has almost not CPU and RAM usage.

And If I check the item agent.ping manually it always responds immediately

[BigSmooth]

I think it check for agent port reachability, isn't it?

[quackduck]

Who knows. It's not documented in any shape or form. The doc just calls it "The agent availability check."

"Return value: Nothing - unavailable; 1 - available"

It might as well represent the number of sad ducks divided by the number of happy ducks in Loch Ness for all we know. *shrugs*.

[ISiroshtan]

What is your agent.ping collection interval?
With expression you shown you asking Zabbix to fire alert if there is no data for 1 second. Given that trigger for no data is rechecked every 30 seconds, if you have collection interval of 30 second also, in theory, it should not fire. The main point if in theory. Zabbix not necessary going to line up the trigger check task with data collection task. On top of that, if there will be a delay in collection data (worker queue, server high load, network instability, etc) you have good change to get a false-positive alert.

I would advise to set no_data time to at least double the collection interval of agent_ping. So if you collecting value every 30 seconds - set no data to 1m. If you collect value every 1 minute - set no_data to 2m. At least. Default Zabbix templates are setting collection to 1 minute and no_data to 5 minute

[cyber]

as nodata is recalculated in 30s then there is no point whatsoever to set that number below 30s... As already said, increase the calculation time..