Server Performance Guide?

[ck1521]

Hello I've been hosting a dedicated server on a ECS with windows OS.
We are a group of about 7-9 players get together and play every night.
Recently we've been experiencing more or less frequent server rabberbanding.
It got seriously out of control when we were in T2 city stations, also fighting thalamus shipwrecks.

We're on a modded sub consist of 700-800 objects, no crazy sensors or logic operators, and I have applied "Performance fix" mod on server (also server-side lua patch), also tried tune up/down the server ticks, but the issue still exists. Server resource monitor shows about 50% CPU load overall (dual core, one of them is 60-100% depending on situations), memory looks OK. Sometime I can see error message like "event count very high", sometime the rubberbanding happens without any particular message in console or server log.

So I'm wondering if there is any performance guide for hosting a dedicated server?
Things I want to know:
1. Is there any mod/server setting I should try first?
2. What in-game objects could be related, so we could avoid or remove it with high priority (e.g. NPC, sensor, logic operators, specific enemy etc.)
3. In case of a performance issue, what info I could provide to help diagnose the problem?
(I turned off server logs since it's mostly player actions, just in case it's related to disk I/O)

[Zothen]

Thats some age-old issues with Barotrauma. Had to struggle with it countless times over the years.

First and foremost: object count. BT hates syncing tons of objects. So the more general stuff there is on a sub the more severe the issues get.
A while ago even stuff in cabinets added to the strain on simulation and network sync. Not sure if there was improvements made on this - you could do a search for that. Extra punch comes from everything thats not stored or bolted down, because physicsa are applied, too.

Then player count - the more players, the more input data to sync.

Then the sub - the more complextiy, size, wireing, objects, lights etc, etc the more strain.
In summary - this stuff adds up. Thats why the issues become more severe the deeper youre into a campaign. If you want a guide - take the vanilla subs as comparision. Everything above adds extra strain.

The bad? This stuff synergizes nicely together.

Solution? Tough call. Strict downsizing. Only use/store what you really need. Get rid of everything else. Avoid overengineering subs. Less is more.
Long term solution: Get your experience heard by the devs. They know, but we shouldnt slack to ask for further optimizations.

Some of the stuff above might be outdated. Do a search, go on Discord, ask the experienced, non-toxic server hosts. (unstable channel is often a good choice to find experienced hosts)

[ck1521]

Originally posted by Zothen:

Thats some age-old issues with Barotrauma. Had to struggle with it countless times over the years.

Thank you for all these information! Looks like there's hell of a lot stuff to work on.
I'll try work on stuff with more things to consider (i.e object with AI, object with physics) and narrow down to static objects and see how it works.
If eventually it can't be helped, I'll see if I can get some extra help, thanks again.

btw, where does all that stress apply to? Is it networking like bandwith, or CPU constrains? Maybe I should check out server resource as well...

[Zothen]

Well, you already said that your core is peaking at 100% and BT is has no multi-core support, so....
Not sure about the networking but generally networking easily take up 20-30% of the process. Cant recall values. Its been a while since Ive checked on those