I’m not an expert of openHab (yet), so someone should correct me or make it more specific, but I don’t think that there is a limit on these files/items. The more file you have the little slower it might get during booting, because it has to parse each file individually, but it won’t affect the performace later, since it’s parsed - ie.: loaded.
The number of items/rules, I haven’t heard anyone complaining about this. There are a couple of users who run OH on RPi and has more than 1000 items for example.
However you should do what you can to apply DRY (Don’t Repeat Yourself) and avoid writing too many Rules that run at the same time as well as Rules that take a long time to Run.
The more lines of Rules files you have the longer boot times and loading and parsing of edits.
Finally, decoupled is good but don’t go out of your way to add decoupling for decoupling sake. There is already a huge amount of decoupling built into OH itself. You should focus on making your Items best represent the model of your home automation in a way that makes sense to you and others. If your model is so decoupled that it doesn’t make sense without grokking the gestalt, no one will be able to help you with problems.
Gestalt is a German word that has entered English, at least in America, through psychology and it means in a context like this “the sum total” with an implied meaning that the total is more than the sum of its parts. If you think of the phrase “Can’t see the forest for the trees”, the forest would be the gestalt.
It’s been awhile since I’ve slipped up with such an obscure idiom on this forum. I think the last one I had to explain was “red herring.” Ain’t English grand!
10 simultaneously running Rules. When you have a sleep in a Rule you are keeping that Rule running but not doing anything, using up one of the threads. By default there are only 5 for Rules (unless this changed in 2.4).
Yes. By default only two Timers or cron triggered Rules can run at the same time (unless this changed in 2.4).
Item naming requirements are documented here. There is no arbitrary limit to the number of Items. A given computer will eventually run out of memory but that would be tens of thousands of Items.
There are always limits because everything at a minimum takes up some resources on a machine. But the there are so many variables involved to calculate what those would be is so high as to not be worth calculating. For example, if you have 1,000 Rules you may only be able to have 10,000 Items but if you have 10 Rules you can have up to 100,000 Items. Everything interacts. It usually isn’t worth trying to figure out unless you have a real problem.
I think this is not correct, or maybe I misinterpret this.
Since OH2.1 I use 8 timers in parallel for a random close/open of my rollershutter. They do not trigger at the same moment but they are running at the same time.
I want to use more timers to controll if a light is switched on for to long. This means I need maybe 10 or more timers run in parallel. (yes, I can use expire-binding for that, but I want to configure timer maximum run time by a number item)