I have been battling the issue of my 198 BACnet/IP points (from one single BACnet/IP device) not updating in a timely manner or not at all after a period of time when configured to COV. The COV subscription period is set to 60 minutes in Mango.
The symptom is that the COV works for a couple of days or less, then nearly all of them stopped updating with new values. However, when a 'force read' was executed, a new value (which is above COV change threshhold) was successfully obtained. At the same time, from another device (not Mango) that is subscribed to the same data source , the points are updating normally. I can discovery/read all points under the device browser tab within the data source UI.
So as an alternative, I proceed to disable all COV on all points and only rely on periodic update of 3 minutes interval and logging set to 'All'. The moment i did that, the poll duration of the data source went up from milliseconds to value like 48100 milliseconds. See below:
One thing that i have noticed is that the 'successful Poll%' always at 100% even while these online/offline issues happening. The events are shown in the second picture.
In order to narrow down the issue, i decided to put all the points back to COV enabled then proceeded to disable the COV setting on a number of them at a time and see when crazy poll duration happened.
Out of the 198 points, i finally reduced the number of points with COV enabled to '25'. The moment I disabled one more out of these 25, the poll duration suffered as shown. I then re-enabled one point with COV, the poll duration went back to normal values. From the screenshot, you can see the changes happen.
In trying to determine if i have misconfigured any settings, i have gone through and manipulated the following settings:
1- Thread pools: 'High priority pool size' (from 0 to 300); High priority maximum pool size' (from 100 to 1000);'Medium priority pool size' (from 1 to 300); 'Low priority pool size' (from 1 to 100). see below:
I have done a couple of thread dumps and am happy to provide them for your review.
By the way, the free JVM memory never went below 2900MB if this helps.
Please let me know if you need more info.