topic Re: host availability state not changing in Alerting

Alert on Host availability - host state isn't changing

Troy — Thu, 18 Dec 2025 13:42:58 GMT

Hello,

Im trying to create an alert based on a hosts availability.state not being "up".
the issue is when i turn off oneagent - it doesnt always set the state to "unmonitored_agent_stopped" it will just leave gaps as shown. so my alert does not always work.

We want to be able to alert on agent being turned off / host being offline and customize the alert which is why we are not using the OOTB option.

DQL I tried using David Anomaly Detection:

timeseries availability = sum(dt.host.availability), nonempty:true, filter:{availability.state != "up" }, by:{dt.entity.host, availability.state}

Re: host availability state not changing

p_devulapalli — Wed, 23 Jul 2025 00:33:16 GMT

@Troy If your intention is to trigger an alert whenever the availability state != up, you can use the timeseries command with the nonempty parameter to calculate host availability. This parameter ensures that you get a result even when no data match the filter, such as when no hosts are up

https://docs.dynatrace.com/docs/discover-dynatrace/references/dynatrace-query-language/commands/metr...

Here is an example you can refer

https://docs.dynatrace.com/docs/shortlink/metrics-on-grail-examples#example-10-monitoring-host-availability

timeseries Availability = sum(dt.host.availability, default:0), nonempty:true, by:{dt.entity.host}, filter:{availability.state == "up"} //| filter dt.entity.host == "HOST-XXXX"

You need to use a threshold to alert if less than 1 and that should do the trick

Re: host availability state not changing

Troy — Wed, 23 Jul 2025 12:30:50 GMT

Ah! I was close - thank you this seems to be working.

Re: host availability state not changing

Troy — Wed, 23 Jul 2025 15:11:41 GMT

@p_devulapalli So this works to a degree - im seeing the alert come in but it will close the problem after some time even though the value is still 0 / agent is still down. any idea how i can fix this?

Re: host availability state not changing

p_devulapalli — Thu, 24 Jul 2025 10:09:25 GMT

@Troy That should not be happening , the problem should not be closing unless there is a change in threshold . Do you still see this happening ?

Re: host availability state not changing

Troy — Thu, 24 Jul 2025 14:57:30 GMT

Hello - Yes I see this happening, the problem gets created and stays open for a few minutes and closes on its own, the alerting is set to 3 ,5, 5 which is the default values. the problem closes even though the agent is still down and value is 0 for availability.

Re: host availability state not changing

p_devulapalli — Fri, 25 Jul 2025 04:41:50 GMT

@Troy That's bit odd , did you add any dimensions that change over time to the anomaly detector event name or description?

Re: host availability state not changing

Troy — Fri, 25 Jul 2025 15:37:00 GMT

Nope - My detector is essentially the same as yours except it is filtering for on Os instead of a single machine. may open a case with Dynatrace if this behaviour is not expected.