[MC-100692] Collisions cause extreme lag

Since 1.9, massive entities in one spot (+400 for me, depends on your computer/server) cause extreme lag. To fix this, just make a 3x3 spot (or more) where will be your entities instead of a 1x1. Or kill them.

How to reproduce:
https://www.youtube.com/watch?v=Vty2f53Ocfc&feature=youtu.be

Linked issues

is duplicated by 1

MC-100696 Since 1.9 entity cause extreme lag Resolved

relates to 1

MC-94438 Server: Mob pathfinding induced massive lag in any versions 15w49a and later Resolved

Attachments

crash-2016-04-05_18.00.53-server.txt

crash-2016-04-06_18.38.27-server.txt

Minecraft Server Lag.txt

Comments 5

user-f2760 2016-04-08T13:43:59Z

then don't do that, the server tries to calculate pathfinding for every single one of those mobs, basically you're just asking for the server to overload

SebTheThing 2016-04-08T13:48:52Z

Do the server has to calculate Boats and Item Frames pathfinding?

François B 2016-04-08T13:49:48Z

Then tell us why it worked perfectly with no lags at all in 1.8, and it's awful in 1.9.

user-f2760 2016-04-08T14:23:36Z

because 1.9 has other memory issues already reported, like MC-94438
as for boats and item frames it's the rendering of them, I will reopen it, but with so many entities as one spot, you are still kinda asking for it

SebTheThing 2016-04-08T15:00:07Z

Collision is the real cause. I tried to place 400 chickens in a 1x1 spot, and in a 7x7 spot and the difference is clearly here.