Question about the performance limits of OpenHAB

What are the performance limits of OpenHAB ? (As the maximum number of rules, things or items.)

What do you plan to equip, some kind of skyscraper ?
I doubt someone knows the exact limits, but I have not seen anyone hit them.

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The OP’s question is akin to asking how long a piece of string is. You have to qualify such a question according to some (hardware, perhaps?) constraints to get a meaningful answer.

For example, a configuration that makes a RPi1 buckle under the load may run perfectly well on a RPi2 or RPi3.

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Since OpenHAB can run on almost anything, being that it’s java based.

Your limit comes from Hardware or any specific hard limits of the technology you’re integrating. Some protocols/technologies/brands have limits of 30 devices others 255.

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I believe my question was not clear enough. I do aim to develop a smart campus with many distant buildings so I actually though of having distributed OH servers and coordinate their roles. My question about the limits popped up to ensure a fast performance considering the response time. So, I believe I should have asked if there is any way to change the OH architecture or the rule execution algorithm to guarantee such performance requirements with the same HW configurations ?
Thank you,

Yes your question was totally unclear, and it still somewhat is. You cannot guarantee performance. Neither OH nor Java nor Linux are realtime systems, and performance does not really depend on the OH architecture.
Of course there’s multiple ways to interconnect multiple servers to each run OH, and how you design the data transfer process will impact performance of the system as a whole. But strictly speaking, that’s no OH thing then.
OH software is multithreaded, and since you can use a server that’s as fast as you need it to be, response times rather depend on the transmission network(s) you use. Well, and on your rules, of course.
The recommended setup is to have a single OH server only, plus MQTT satellites if required - if that was your question.

Sounds like a solution, Thank you.
But let me ask clearly about the algorithmic limitations of OH itself (undelying algorithms) without considering the other factors like the NW transmission as you said?

I don’t understand. There’s no such thing as “algorithmic limitations”.