Need help is checking a function in Zabbix

[Vieypul56]

Hi, We are monitoring hundreds of thousands of nodes and parameters through Zabbix 4.2.4. Recently we came across an issue whereby we need to add 1 trigger/function whenever the value changes from Integer to String Error. Is there a way that can be done using trigger function or something? I am really looking forward to implement it without cloning or adding new parameters which will add performance issue to the system. Thanks in adv.

[Hamardaban]

You can use preprocessing and the ability to handle error by Custom on fail option.
If you describe your situation in more detail, it is possible to offer a more specific solution.

[Vieypul56]

Sure Hamardaban.

We are polling node parameter based on SNMP OIDs every 5 mins for almost 200+ parameters and 2200 nodes in a server. The values are float and hence we took datatype as "Numeric(float)".
But at certain times the value comes as text as an error "Connection error/device off" and we are not able to capture it. After 2-3 hrs when the device again responds float values it works fine.
But we are concerned to capture the alert and make a trigger whenever we face such error situation which comes in string which will help us to identify and inform concerned team for troubleshooting.

Requirement:

To have a trigger whenever the node parameter value changes from "float" to "Numeric".

[Hamardaban]

Using the Custom on fail option, in case of an error (a string came, not a number), you can assign the item a value that is not found in the work - for example 987654321. And create another trigger that responds to such a value.

[Vieypul56]

Hamardaban - Above solution worked but got me in another situation. I have 40 such parameters, out of only 10 per device are Active but they are random. Now, how can I exclude the unsupported ones else 30 false alarms would be generated.

[Vieypul56]

Thanks Hamardaban for your response but I don't see custom in the functions. They are all predefined.

[Hamardaban]

I didn't write about functions, but about preprocessing.

[Vieypul56]

Absolutely, it was my mis-interpretation.

[Vieypul56]

Hamardaban : Thanks for all your support. I managed to perform the requisite task by using combination of functions in triggers. Thanks !

[Hamardaban]

There is a processing of such a situation "Validation -> Check for not supported value". https://www.zabbix.com/documentation.../preprocessing
I don't remember exactly what version it appeared in. But 4.2 is not supported for a long time - you need to update!

[Vieypul56]

Thanks Hamardaban, I will look into it. Thnx

[Hamardaban]

I have 40 such parameters, out of only 10 per device are Active but they are random. Now, how can I exclude the unsupported ones else 30 false alarms would be generated.

Inactive item's are disabled? Then there are no problems - triggers for such elements do not work. Or in the "not supported" state and there are a lot of them? Then you may have problems with the performance of the entire system. And you need to review all the metrics system.

[Vieypul56]

They are not in disabled state. They vary from device to device and randomly changes every 2-3 days. They all are under common template.
Is there a way we can exclude the "not supported" status ones from this custom trigger by any means.?

[cyber]

Item most probably turns to "not supported" state in this case...you could also create an internal action to catch those events, when item turns to "not supported"