As OpenNMS is enterprise-grade, the goal is to be able to monitor tens of thousands of devices. While I can’t speak for the community as a whole, at the OpenNMS Group we have a couple of clients in the 40,000 device range on a single server.
We are working with one of them in Geneva, and we ran into a problem. With 40K+ nodes and 29 categories, the Real Time Console (RTC) was taking almost 4 hours to start. David and Matt went to work on optimizing the code, and they were able to show some improvement:
Previous RTC code init time: 3 hours 47 minutes
Current RTC code init time: 1 minute 19 seconds
This is in HEAD now, but I am going to see about porting it back to stable.