[2020] Persistence - How & Why

Originally posted by Doyler92

Doesn't this just mean "no because we don't have time"?

Originally posted by zombietopm

You're not able to reproduce it in house because you need people actually playing the game. These are player caused crashes. I've got a dev server and a prod server. Both identical right now. My dev box I forgot to shut down yesterday and has been up running for 18 hrs. The tent I placed yesterday to test forced terminations is still where I left it, obviously because the server never crashed in the 18 hours.

My prod server that actually has players on it, has crashed like 3 times in those 18 hrs. At some point my buddies barrel disappeared. But just one. His other one that was right next to it is was still there.

Also before I modded my servers, I had placed 3 tents and went to loot more. Crash happened. Worked my way back to the tents and 1 had vanished. Day or so later, they were all gone.

Also just last week I spawned in a bunch of stuff to build a few towers and a big compound. It last like 3 days. Then vanished.

Originally posted by The_Eastman

So just to be clear we are talking about the same thing here. Having the server write to a temp file first instead of directly, is something that would take months to optimize?

Originally posted by zombietopm

I placed a tent yesterday on my prod server around 2pm cst. Some time between then and now, there were a hand full of crashes. During that same time, my dev server was up and crashed 0 times. Tent on prod is gone. Tent on dev is still there. I've got my crash log if you wanna look at it.

Originally posted by ZomboWTF

hey eugene, have you guys considered using an sqlite file based db to gradually save change to the world? in this way you wouldnt have to rewrite a whole file everytime a server kicks the bucket

sqlite has a few limitations though

Originally posted by Doyler92

It's sad that after years of waiting you guys decide that you can't work for a few more months to make it actually work right. This decision to just rush it out to a final release sucks.

Originally posted by Naut1c

hi eugene, probably you know this already, but i think maybe your current way of dealing with persistence is not optimal. even server restarts that break writes, should not cause a wipe of any sort.

instead it should be some kind of eventsourced system, where every change is written incrementally, without affecting a 'big state file'. only the loading of these incremental changes would then evaluate the current and complete state.

so this means, even if the server is killed within a write, only one change file would be broken. and when it is, you just leave it out when loading the state, as if it never happened.

this system would not only make youre persistence much more stable, it would also make it easier to reproduce and tackle bugs within persistence.

of course it is a challenge to get it right and performing well. but i believe this is the way to go.

Originally posted by ItsMyOnlyOption

/u/eugenharton

Just reinstalled the two instances we are running, this time 2 seperte installations, 2 different directory's.

Same behavior. One instance gets shutdown properly, and for the other one we can see the console closes, but the server executable keeps running.

Is it possible we get a #save option? so we can force a safe prior to an ungracefull shutdown?