Maybe you are running out of JVM memory. There is a memory leak in 3.9.2/3.9.3 (actually it is in 3.9.1 also, but not so big) https://community.igniterealtime.org/thread/52516 So maybe your server is reaching the limit and users start to pop out of the server. Does the server restart helps with the issue for some time?
The highest it’s been is 35mb. A server restart this morning did not really change that number and it did not fix/alter the problem of users dissappearing.
I wasn’t sure to split up my post but yeah. I’ve kept my eye on the memory usage and it keeps jumping consistently all day. If I do a ‘top’ at the Linux console java is using about 11% of the total memory, about 2116m VIRT, 211m RES and 13m SHR. So it’s not using too much but the java VM still oscillates (memory leak) and needs to be debugged.
I defintely have the same issue here, we upgraded and everyone in the enterprise here has noticed the issue. We run ours on a windows machine. I think this is a bug that is pretty widespread it seems.