Lost tags on Zabbix upgrade from 7.2.14 to 7.4.5

[luca.cavana]

Hello,

I recently updated my Zabbix infrastructure from 7.2.14 to 7.4.5; subsequently I also updated the templates from Zabbix repositories.
Everything went good, except that the following night while running the backups I got flooded by e-mails because all the tags I have defined for the selective maintenance of different triggers have disappeared from the hosts they were defined to.
The hosts that lost the tags had the attached template "Windows by Zabbix agent active" upgraded from 7.2-x to 7.4-2

Did I miss something while updating the server infrastructure or the templates?

Thank you,
Luca

[cyber]

Did you look closely what changes were done, when you upgraded that template? I would assume your additional tags were just removed.. But that is by "design"... Unfortunately, there is no "consolidate" option...

[luca.cavana]

Did you look closely what changes were done, when you upgraded that template?

I always watch quite closely for changes when importing templates.
If necessary, I modify the new template's YAML before importing it.

But these tags where defined directly on few selected hosts, not on a template level.
What do you think happened here? Oversight from my part or the new template changed the item definition and with that, new items were created and old one deleted and with them the tags on the hosts?

[cyber]

Ok, host level tags... Template should not touch those... as long as I understand it...
But you also mention items, so that might be only logical option, if you aded some tags to items directly on host, then this item gets updated (maybe) and tags gets lost as you say... But I think it needs to be verified, I rarely add tags to items outside of template, so never had such issue...

[luca.cavana]

Ok, host level tags... Template should not touch those... as long as I understand it...
But you also mention items, so that might be only logical option, if you aded some tags to items directly on host, then this item gets updated (maybe) and tags gets lost as you say... But I think it needs to be verified, I rarely add tags to items outside of template, so never had such issue...

That is also my understanding. I'll let you know at the next upgrade as this was my first Zabbix upgrade.