Kamil Pigłowski

About debug reports - maybe this is because after 1.14.4 you have closed the most important ticket about performance and stated that 1.14.4 is final 1.14 release and there will be no more performance fixes and you now focus on releasing 1.15 in which you eventually might start working on performance again. So people just gave up.

There is hard to tell about a specific performance issues because the whole 1.14+ and still 1.14.4 is one big performance issue. There were tons of specific reports for example in https://bugs.mojang.com/browse/MC-138550 but the ticket has been closed. Besides, players who paid for the product are not your employees. Maybe hire your own quality control or beta testing team. Let this team just start a good-hardware server and make it for 10-20 people. Let that team play the game normally for a couple of days, explore, trade, breed, fly elytra, do some raids, just play the game normally and you will see how dramatically bad it is comparing to 1.13.2 (not even to 1.12.2). You will see for yourselves how many lag spikes freezing the game even for a couple of seconds there are, how many TPS drops below 10 there are, and how many general lags and shutters there are. Figure it out yourselves why is that, do reports on your own. When players are trying to help giving you most accurate info possible comming straight from their gameplay and attaching tons of reports like in https://bugs.mojang.com/browse/MC-138550 then the biggest ticket like this one is... closed...

Please make this issue top priority.
This really drops servers down to the point where only restart can help and it is very easy to reach this bug if couple of players are exploring on the server. The fastest way to reach it is also via Nether if boat highways with ice are used.
Most likely, this issue is not related to memory leak, because on my 1.14.3 server RAM usage is fine and not seem leaking while experiencing this problem.

On my server with pure 1.14 world with 2 people exploring the overworld and generating new chunks, one of them on horseback and second one with speed potion, server TPS dopped to as low as 10, creating huge lags and making the server unplayable (restart needed). Chunks generating in 1.14.3 seem to be better than in 1.14.2 but is still way too slow comparing to 1.13.2. Couple of players exploring or only one with elytra is still overkill, even to dedicated high-end server like mine (Xeon 4-cores and 16 GB RAM).

UPDATE: with 2 people exploring the overworld and generating new chunks, one of them on horseback and second one with speed potion, server TPS dopped to as low as 10, creating huge lags and making the server unplayable (restart needed). Chunks generating in 1.14.3 seem to be better than in 1.14.2 but is still way too slow comparing to 1.13.2. Couple of players exploring or only one with elytra is still overkill, even to dedicated high-end server like mine (Xeon 4-cores and 16 GB RAM).

I forgot to mention - this is with raids and elytra disabled at the moment.

Generally, after update to 1.14.3, first hour on my two servers seem to be fine and working better comparing to 1.14.2, especially chunks loading.
But we can really see about that after at least couple of days, to be sure if 1.14.3 is working better than 1.14.2.

@Johnibur
I'm on 1.14.2

@Justin
I can definately confirm this after my observations from today.
On my other server, with most of the world generated on 1.13.2 and then updated to 1.14.2 performance is quite ok. Not as good as 1.13.2 and there are stille some lags but it's a huge difference comparing to my server with pure 1.14 world. There are still some lags but not so big and the server runs pretty smooth. When I explored far away on this server and started to generate NEW chunks on 1.14 chunk loading and generating was of course much worse that in 1.13.2 but acceptable. TPS was still stable 20.
HOWEVER, when I discovered the first village generated in 1.14 server TPS started to drop drastically introducing huge lags with all symptoms in this thread and server eventually crashed...
Something is clearly wrong about villages and villagers behaving in 1.14. Villages and villagers in 1.14.2 are major gamebrakers and server killers, much worse issue than just chunk rendering itself.

Yes, it is well known that CPU usage is enormously high in 1.14 compared to 1.13.2.
I think this issue is related to: https://bugs.mojang.com/browse/MC-138550

You are probably experiencing very low TPS and huge lags, related to general problem here: https://bugs.mojang.com/browse/MC-138550

Something is wrong with some villagers pathfinding a bed during nights. Probably looping and causing tps drops.
We had big tps drops during nights and when we destroyed all beds close to villager farms TPS started to behave much better.

Currently, in our opinion (we run two powerful dedicated servers on 1.14.2) the biggest problem causing huge lags and enormous server tps drops are:

• far exploration, especially using elytra or boats (flying elytra by just 1 player can drop TPS below 10 very fast and make the server unplayable);

• meeting pillager patrols (something is wrong with their AI, sometimes making even single patrol to start dropping server TPS);

• initiating raids of pillagers (raids are sometimes causing huge TPS drops);

• creating villager farms (it seems their AI is bugged and some villagers can drop server TPS);

• going frequently through Nether and End portals (causing lag everytime going through portals).

And this is all with only 12 people on the server and render distance as low as 6.

In comparison - same server could easily handle 30 people and render distance 15 back to 1.13.2 without ANY lags and with constant 20 TPS.

I'm talking about 1.14.2 version server.
Not sure if it is any better at 1.14.3 pre-1.

@violine1101
Do you have any info is there a chance Mojang will fix dramatic server-side performance issues in final 1.14.3 release?
Do you have any info are the devs aware of this issue and at least working on it?
Your answer would be much appreciated.

@MetoolDaddy

This confirms my opinion also.

Recently after many days of observations I discovered - and now I'm 100% positive about it - that one of major impacts of server-side performance is broken new AI of mobs, especially pillagers and patrols. My server keeps stable 20 TPS but when I meet a patrol TPS starts to drop and after wiping out the patrol it is raising again back to 20. I think this is something very critical that devs should look into to make the game playable again.

Recently after many days of observations I discovered - and now I'm 100% positive about it - that one of major impacts of server-side performance is also AI of pillagers and patrols. My server keeps stable 20 TPS but when I meet a patrol TPS starts to drop and after wiping out the patrol it is raising again back to 20. I think this is something very critical that devs should look into.

My server is Xeon 4-cores, 16 GB RAM, SSD HDD. This is one of the most high-end hosting plans on the market.
Back to 1.13.2 I could handle 30+ players with 15 render distance with constant 20 TPS and zero lags. 16x16 = 256 chunks per player x 30 players = 7680 chunks active.
Currently on 1.14.2 same server can't keep up with 10+ players with 6 render distance and often drops TPS to as low as 11-12 with huge lags. Restarts are needed even every couple of hours.
Once again, with only 10 players and render distance as low as 6. 7x7 = 49 chunks per player x 10 players = 490 chunks active.
How is this possible that the same powerful server is running on 1.14.2 much worse, with 15 times lower chunk load than it was on 1.13.2?
We don't need any your new lighting engine or new AI of mobs or whatever else that makes the game 15x more demanding and simply unplayable.
If you can't optimize it or even test it before releasing to the market just please don't do it... don't ruin that great game you've made.
Please fix broken chunk loading algorithm or this terrible overloading AI of mobs or whatever else and make the game playable.
Or maybe rollback to the previous mechanics from 1.13.2 and just let current 1.14+ worlds work on them.

There are even no hosting plans so high-end on the market.
I currently run my 1.14.2 server on Xeon 4-cores, SSD HDD and 16 GB RAM with render distance as low as 6. And TPS with 12 players is terrible - only 11-12. The server seem to be playable only below 10 players...
Back to 1.13.2 I could easily handle 30+ players on 3-cores and 10 GB RAM with render distance 15 and TPS constant 20.
This is simply a kind of joke... Did they at least run this game even once on a real test server before releasing it? We have now 1.14.2 and it is still as bad as 1.14.

Try the latest Spigot build - I can confirm that 1.14.2 on latest Spigot from today became playable now and as "good" as 1.14.1 !

I got the same message in console as well as lag:
Unable to resolve BlockEntity for ItemStack: minecraft:air

Sure, already did.