Changing trigger expression in template doesn't propagate?

[quackduck]

I've changed the trigger expression in a template, but it has no effect on the hosts.

[quackduck]

Only way to get them to update on a host is to unlink and clear the template and re-apply it, which is kind of nuts.

[PavelZ]

No, it works as you expect and naturally. Expressions are updated immediately.

Have you made sure that the trigger is actually still attached to the template and not separate?
What version of the program are you using? Have you looked at the bug tracker?

[quackduck]

Sorry, I need to correct myself. This is the case for discovered triggers. Seems like zabbix is making instantiations of discovered triggers, but changes doesn't propagate when altered - you need to make sure that the instantiations happens again e.g. by unlink/clearinging the template and starting over. It's an oversight and I'd gladly bug report it for free if the bug reportig would let me report it without going through som registration process and what not.

If anyone is going to bug report this, it's worth checking whether a re-instaniaion of a discovered trigger would also remove an active problem and trigger a new one. That should be considered a bug too IMO.

[PavelZ]

ok.
Now the next step in learning Zabbix: try to find out how the so-called Discovery Rules work and start them manually.
With filters in the UI you can even run rules for several hosts at once.

I agree, sometimes you want it to happen even faster, but then large installations will provide a heavy load.
Things turned out the way they did. We got used to it.

[Brambo]

quackduck also discovery triggers are updated. Only you need to understand that any update of discovery items/ discovery triggers are only updated/processed when the discovery rule is activated on the host.
So when the discovery rule has an interval of 2 hours it could take up to 2 hours to see changes.

I do a lot with discoery rules and it's basically the foundation of all my self created templates. And I know for certain it works. My discovery LLDs are almost always depending on a other source item. But to reduce server load I have made myself a so called LLD helper which has only the needed values in JSON format with a discard on change pre-processor. The time value there is a {$macro} which I then can set / easily change on template or host level.

With version 7.x: good to know is that LLD is done on the server, normal item pre-processing is done by on a proxy if you have them. To throttle the LLD my server load is greatly reduces.