if number of shards/tenants increases , cpu usage also increases even in idle and very less number of objects in each shards. As far as tracked profile using go profiler it seems CycleManager package plays a significant role in consuming cpu .
I understand your concern about the CPU usage seem odd for small shards count.
You’re currently on version 1.28.11. There have been several performance optimizations and bug fixes. Before dive deeper into this, I’d upgrade to the latest version (1.31.0) first then test. This will help to see if this is something need to be looked at or addressed.
Could you test on 1.31.0 and let me know if you see the same behavior?
Also, here’s our resource planning documentation which have helpful information:
Best regards, Mohamed Shahin
Weaviate Support Engineer (Ireland, UTC±00:00/+01:00)