Increased Step Contacts and updateNOUOwners (MicroProfile) causing extreme lag

Heyho everyone,

I am experiencing some strange behaviour. So yesterday we started to introduce a boat system to our game. Which we also tested internally and couldnt find any struggle with. As soon as we added it we could see our server frame rates drop down to almost 0 after certain time, we’ve spent the past few hours investigating and could already eliminate a few issues. The main one remains though, after a while the ContactsCount start climbing upto 200,000 which before the update was 0 or at least very close to 0 at all times.

We also ran a MicroProfile of one of the broken servers, you can clearly see that updateNOUOwners and Step Contacts are massively increased compared to normal servers. I have attached both the MicroProfile of a healthy server without boats and a broken server with boats below.

BrokenServerWithBoats.html (2.1 MB)
HealthyServerWithoutBoats.html (785.4 KB)

What I find really strange is that even after the boats are destroyed the server will continue to lag, the contactscount also wont decrease. I would be very excited if someone has an idea of what could be causing this or if someone’s better than me at reading these MicroProfiles.

I wanna note that we were not able to reconstruct this behaviour in testing at all, even when having multiple players play the test game. I am completely clueless on this topic unfortunately.

You can find a reduced version of our boat below:
------- DELETED ---------

Please note its a heavily modified version of this boat chassis, where we moved most calculations to the client (the code might not be the cleanest afterall)

The boats are using roblox terrain water for their collisions however due to Network Ownership I dont see how that would impact the server so heavily. Especially since it first does not seem to effect the server. Even in testing we could never have the boats effect the server’s performance.

King Regards
Dan

4 Likes

Quick Update: We just tested with a completely different system and could still experience these issues. Therefore its most likely not the actual boat. If anyone has an idea on where we can start looking based on the MicroProfiles I would be amazed.

Unfortunately it still only seems to happen when our players can interact with water in one way or the other.

We have identified an internal issue with a new collision group being inserted by that boat script. The bug is not longer occuring (hopefully …).