Currently my only workaround is to deactivate global override and individually set to 7d and master items to 0.

Hello Markus,
Your statement is fully correct. But this is more a feature request rather a bug, so moved it here.

Additionally - I would say that this becomes a problem not only with Timescale support, but also without it since Zabbix is more and more about pre-processing and dependent items. Quite often users have a master item that gathers big amount of data which is being extracted by dependent items, and general Idea is to drop that huge data chunk in preprocessing stage without storing to database.

In a large environments quite often Override housekeeper is used, and that again will negatively affect such master items.

There is an alternative to global overrides — user macros.

@Glebs - that is my current workaround. I define an global macro {$DEFAULT_HISTORYPERIOD} = 7d and use use that in the items. Actually it's one of the first things I change in all my installations and on all Templates/Items. TBT I often have thought to bring that in for a change request.

But i still see how it is better to provide the global override - it just should honour the 0 setting!

@Dmitrijs - I thought it would fit better as a bug as I really thought it worked in previous versions. But I'm happy you see that as a problem too.

Official templates don't always follow the best practices of template building. As far as I recall discussions during ZBXNEXT-1675 implementation, it was decided not to use macros in update intervals and history/trend storage settings in official templates in order to keep them "humane" and easier to understand for Zabbix beginners. But you can still try to convince Zabbix to do this by filing a feature request and gathering few votes. Sometimes people do change their minds.

I think that Zabbix must not overwrite history storage period for items configured to have no history (i.e. item history period set to 0).

Another option could be to override only if the item period is larger. eg change the terminology there to "Maximum history period" or similar. This might be useful in some use cases, where no partitioning is used, but user would still wants smaller history period for some items.
Example:
Override max history to 30 days, but user has some items, that update really often, but do not require that much history. For such items, 1 day might be enough history and the setting might be honored in this case.

Fixed in:

• 4.0.11rc1 f2770b316ef
• 4.2.5rc1 c9fc882527c
• 4.4.0alpha1 (master) 5f0957e8233, 97259c1bda8

Documentation changes:

• Item configuration: 4.0, 4.2, 4.4
• What's new: 4.0.11, 4.2.5