mojira.dev
MC-227202

Slow world loading after 1.17-pre3

After upgrading one of my dedicated servers to 1.17-pre3 the world took significantly longer to load on server start up. The preparing spawn area phase counted all the way up to one hundred and threw an exception which was not the behavior on 1.17-pre2 and below. Before the console would output zero percent a few times and jump to something like 7 percent before stating that the world was done loading and displayed the time it took. In 1.17-pre2 the server took 2.644 seconds to load and in pre3 and pre4 it took 8.98 seconds and threw the following exception between 1% and 2% of the preparing spawn phase.

[Server thread/ERROR]: No key size in MapLike[{extra_size:2,min_size:1,type:"minecraft:column_placer"}]
[Server thread/ERROR]: Exception loading structure piece with id minecraft:jigsaw
java.lang.IllegalStateException: Invalid pool element found
	at dbf.k(SourceFile:54) ~[server.jar:?]
	at java.util.Optional.orElseThrow(Optional.java:403) ~[?:?]
	at dbf.<init>(SourceFile:54) ~[server.jar:?]
	at cuc.a(SourceFile:151) ~[server.jar:?]
	at cni.a(SourceFile:415) ~[server.jar:?]
	at cni.a(SourceFile:175) ~[server.jar:?]
	at abe.l(SourceFile:511) ~[server.jar:?]
	at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1764) ~[?:?]
	at aqu.c(SourceFile:151) ~[server.jar:?]
	at abp$a.c(SourceFile:527) ~[server.jar:?]
	at aqu.z(SourceFile:125) ~[server.jar:?]
	at abp$a.z(SourceFile:536) ~[server.jar:?]
	at abp.d(SourceFile:279) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.bg(SourceFile:771) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.z(SourceFile:759) ~[server.jar:?]
	at aqu.c(SourceFile:134) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.y(SourceFile:744) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.b(SourceFile:525) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.e_(SourceFile:357) ~[server.jar:?]
	at aas.e(SourceFile:183) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.x(SourceFile:665) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.a(SourceFile:274) ~[server.jar:?]
	at java.lang.Thread.run(Thread.java:831) [?:?]
[Server thread/ERROR]: No key size in MapLike[{extra_size:2,min_size:1,type:"minecraft:column_placer"}]
[Server thread/ERROR]: Exception loading structure piece with id minecraft:jigsaw
java.lang.IllegalStateException: Invalid pool element found
	at dbf.k(SourceFile:54) ~[server.jar:?]
	at java.util.Optional.orElseThrow(Optional.java:403) ~[?:?]
	at dbf.<init>(SourceFile:54) ~[server.jar:?]
	at cuc.a(SourceFile:151) ~[server.jar:?]
	at cni.a(SourceFile:415) ~[server.jar:?]
	at cni.a(SourceFile:175) ~[server.jar:?]
	at abe.l(SourceFile:511) ~[server.jar:?]
	at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1764) ~[?:?]
	at aqu.c(SourceFile:151) ~[server.jar:?]
	at abp$a.c(SourceFile:527) ~[server.jar:?]
	at aqu.z(SourceFile:125) ~[server.jar:?]
	at abp$a.z(SourceFile:536) ~[server.jar:?]
	at abp.d(SourceFile:279) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.bg(SourceFile:771) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.z(SourceFile:759) ~[server.jar:?]
	at aqu.c(SourceFile:134) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.y(SourceFile:744) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.b(SourceFile:525) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.e_(SourceFile:357) ~[server.jar:?]
	at aas.e(SourceFile:183) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.x(SourceFile:665) ~[server.jar:?]
	at net.minecraft.server.MinecraftServer.a(SourceFile:274) ~[server.jar:?]
	at java.lang.Thread.run(Thread.java:831) [?:?]

Linked issues

Comments 21

Just to confirm, the same thing still happens in 1.17-pre4?

Yes it still occurs in pre4 and pre5, but the issue is no longer present if I downgrade the server to pre2 or below.

Do you have any world generation datapacks enabled?

No, I have left the world to generate with what the default generation for the snapshots. I also skipped updating to the snapshots with the noise caves and world height changes so I haven’t touched anything with the world nbt or used the 1.18 terrain on this server.

was testing 1.18 gen datapacks also lagging

11 more comments

Can confirm in 21w42a.

Can confirm in 21w43a, and it has gotten significantly worse with the introduction of the chunk blending algorithm.

World loading time is something like 5x the time it took pre 1.17

(your results may vary....mine have been garbage)

Can confirm in 1.18 Pre-release 1.

Can confirm in 1.18 Pre-release 3.

EcoBuilder13

(Unassigned)

Confirmed

Platform

Normal

Datafixer, Performance

1.17 Pre-release 4, 1.17 Pre-release 5, 1.17 Release Candidate 1, 1.17 Release Candidate 2, 1.17, ..., 1.19.1 Pre-release 1, 1.19.1 Release Candidate 1, 1.19.1 Pre-release 4, 1.19.1, 1.19.2

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