Nicklas Ekstrand

Version: 1.16.4

I have attached a region file from our server that has been running for almost 6 years. In at least one region file there are observers and repeaters with totally incorrect time values and removing and replacing the blocks doesn't reset the time values.

The problem was also covered in a video: link Funny repeater bug

(Please note that the attached region file is slightly modified compared to the one in the video.)

NBTExplorer showing the problem when a broken observer is replaced by a repeater:

Hi. My world is 6GB and not that easy to upload. But I selected the .mca files that I considered to be relevant and uploaded the world to Google drive: https://drive.google.com/file/d/11GaefZl3kZcmT1KhsUYoi7W9T_u5NlmI/view?usp=sharing

From the logs it's possible to find:

[21:50:47] [Server thread/INFO]: NicklasE99[/192.168.1.5:60070] logged in with entity id 170 at (4639.194719865757, 151.0, 5722.499564972287)
[21:50:47] [Server thread/INFO]: NicklasE99 joined the game
[21:51:09] [Server thread/ERROR]: Failed to save chunk
java.lang.NullPointerException: null
        at gw.a(SourceFile:91) ~[minecraft_server.18w10a.jar:?]
        at bil.a(SourceFile:422) ~[minecraft_server.18w10a.jar:?]
        at bil.a(SourceFile:187) [minecraft_server.18w10a.jar:?]
        at sd.b(SourceFile:225) [minecraft_server.18w10a.jar:?]
        at sd.a(SourceFile:251) [minecraft_server.18w10a.jar:?]
        at se.a(SourceFile:845) [minecraft_server.18w10a.jar:?]
        at net.minecraft.server.MinecraftServer.a(SourceFile:446) [minecraft_server.18w10a.jar:?]
        at net.minecraft.server.MinecraftServer.v(SourceFile:645) [minecraft_server.18w10a.jar:?]
        at net.minecraft.server.MinecraftServer.run(SourceFile:532) [minecraft_server.18w10a.jar:?]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_151]

BR,

Nicklas

I also encountered this error. I use a copy of our server world running 1.12.2. When I start a copy of this world in 18w09a I get these printouts continuously, i.e., several of them every 45s.

The problem is easy to reproduce but in case you need a test world to show the problem, please let me know.

This is a really terrible performance issue. I really hope there will be a fix soon.

If I understand it correctly the main issue is when going from the nether to the overworld.
1) The caching of portal positions that are done uses the destination coordinates as key for the cache. But since the floating point values from the nether position is multiplied with 8, the resulting destination may be 8 different value in the overworld from each portal block in the nether. The cache values are deleted after 300-400 ticks if not reused. My suggestion: the cache key needs to be based on the portal block that is entered rather than the destination. Increase cache time by a factor of 2 or 3, or only update the cache when portals are created/destroyed.
2) When there is no cache hit, a full search is performed from -128 to +128 on both x and z axis and the full height of the world. That is a lot of blocks to scan for a portal. My suggestion is to improve the scanning by searching in order of distance to the center point. Once a portal block has been found, the search can be terminated and thus not all blocks needs to be scanned.

If you look into the code via MCP, the relevant class is net.minecraft.world.Teleporter and methods placeInExistingPortal() and removeStalePortalLocations().

We have the same problem on our server. After a few people have been online for a while and then log out, the server will still consume 100% CPU until the server is restarted. My initial testing points towards chunks not being properly unloaded. I'm setting up a clean world to verify this.

The bug is marked as "Fixed" but there is not yet a pre2 release. The game is crashing all the time. Is there a workaround while waiting for the next release? (I notice that not all players are affected by this crash)

Regarding Zombies: I did the same test with "difficulty peaceful" on our server (reported in MC-97860). The problem remains and the CPU is still at (or close to) 100%. Zombie AI may be an issue but it's not the only one. In one area where the problem arises we have a lot of the following: villagers, hoppers and free floating items (overfull guardian farm).

That duplication is not correct. MC-63590 is about the watchdog because a property could be set to 60s instead of something lower.

This issue is also watchdog. The reason for the watchdog must be determined. I cannot do this, I have not access to the source code. The problem was introduced int 15w50a. We had watchdog crashes on earlier snapshots as well but in 15w50a everything started lagging and we get a lot of crashes. The game is not playable as it is the 15w50a snapshot.

Executive summary: Something introduced in 15w50a is causing the game to lag badly.

I'm getting this issue on my server. I have not seen it before but it is very much present in 15w47c:

[19:06:17] [Server thread/ERROR]: Failed to save chunk
e: Saving entity NBT
at ro.e(SourceFile:1302) ~[minecraft_server.15w47c.jar:?]
at ro.d(SourceFile:1243) ~[minecraft_server.15w47c.jar:?]
at ask.a(SourceFile:216) ~[minecraft_server.15w47c.jar:?]
at ask.a(SourceFile:102) [minecraft_server.15w47c.jar:?]
at lo.b(SourceFile:147) [minecraft_server.15w47c.jar:?]
at lo.a(SourceFile:166) [minecraft_server.15w47c.jar:?]
at lp.a(SourceFile:885) [minecraft_server.15w47c.jar:?]
at net.minecraft.server.MinecraftServer.a(SourceFile:370) [minecraft_ser
ver.15w47c.jar:?]
at net.minecraft.server.MinecraftServer.C(SourceFile:570) [minecraft_ser
ver.15w47c.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:456) [minecraft_s
erver.15w47c.jar:?]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_65]
Caused by: java.lang.NullPointerException
at zr.b(SourceFile:429) ~[minecraft_server.15w47c.jar:?]
at aai.b(SourceFile:134) ~[minecraft_server.15w47c.jar:?]
at ro.e(SourceFile:1284) ~[minecraft_server.15w47c.jar:?]
... 10 more

I have the same crash on my server. Attached crash report.

I created a new server world in 15w33b and the problem is still there. Tested with flowers, cows and villagers. They all disappear after entering the portal. However, there is no error message in the console nor in the log file.

I also have this problem.

I also have this problem.

This issue was fixed in the final 1.8.2 release.

No, I haven't seen this problem in a while. We may close this issue.

Nope, MC-63590 has a different call stack and is also applicable for 14w30c. This crash doesn't happen on 14w30c (but almost immediately on 14w31a).

I don't think it's possible to properly tame the rabbits in multiplayer (on a server). I tested with a new singleplayer world and it worked. I started a new server and didn't work. The rabbit will always get hearts at the first attempt but will not be tame.

Were you able to get the server running at all?

No no, this has nothing to do with resource pack. I get the same problem when everything is vanilla. The scoreboard is just missing.

Confirmed. I can't play on any of my worlds. Crashes all the time.