MC-141484Entities stay on the global list even when the chunk unloaded
The bug
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23×23 area around them are unloaded. Though that might only be the case when the player leaves the chunks. By changing the render distance I was also able to get entities staying on the list which were over 30 chunks from the next loaded chunk.
How to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0
- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]} - Run the following commands
/execute at @e[tag=MC141484] as @e[tag=MC141484,distance=..1] run say @s /say @e[tag=MC141484]
→ Both should output the entity
- Teleport about 10 chunks away.
/tp ~160 ~ ~
- Run the commands again
/execute at @e[tag=MC141484] as @e[tag=MC141484,distance=..1] run say @s /say @e[tag=MC141484]
→ Only the latter will output the entity now
Interpretation
/say @e[tag=MC141484]
This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
/execute at @e[tag=MC141484] as @e[tag=MC141484,distance=..1] run say @s
This command will first find the entity using the global list but then use the local chunk list to find the entity again. Only if the entity can be found on both lists it will produce an output.
The bug is, that the entity is not removed from the global entity list.
If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23×23 area around it are unloaded.
Linked Issues
MCPE-77266
![[Mojang] Panda](../../../data/avatars/users/41658.png){kind=small}
Created Issue:
Entities only get removed from the global list if a 23x23 chunk area around them is unloaded
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Steps to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0
- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Steps to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0
- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Steps to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}- Run the following commands
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Both should output the entity.
- Teleport about 10 chunks away.
/tp ~160 ~ ~- Run the commands again
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Only the latter will output the entity now.
Interpretation:
/say @e[tag=MC141484]This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
/execute as @e[tag=MC141484] at @s run say @e[distance=..1]This command will first find the entity using the global list but then use the local chunk list to find the entity again, and this time it is not found. This is likely because the chunk is unloaded and therefor has no local entity list.
The bug is, that the entity is not removed from the global entity list.If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23x23 area around it are unloaded.
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Steps to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}- Run the following commands
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Both should output the entity.
- Teleport about 10 chunks away.
/tp ~160 ~ ~- Run the commands again
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Only the latter will output the entity now.
Interpretation:
/say @e[tag=MC141484]This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
/execute as @e[tag=MC141484] at @s run say @e[distance=..1]This command will first find the entity using the global list but then use the local chunk list to find the entity again, and this time it is not found. This is likely because the chunk is unloaded and therefor has no local entity list.
The bug is, that the entity is not removed from the global entity list.If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23x23 area around it are unloaded.
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Steps to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}- Run the following commands
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Both should output the entity.
- Teleport about 10 chunks away.
/tp ~160 ~ ~- Run the commands again
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Only the latter will output the entity now.
Interpretation
/say @e[tag=MC141484]This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
/execute as @e[tag=MC141484] at @s run say @e[distance=..1]This command will first find the entity using the global list but then use the local chunk list to find the entity again, and this time it is not found. This is likely because the chunk is unloaded and therefor has no local entity list.
The bug is, that the entity is not removed from the global entity list.If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23x23 area around it are unloaded.
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Steps to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}- Run the following commands
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Both should output the entity.
- Teleport about 10 chunks away.
/tp ~160 ~ ~- Run the commands again
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Only the latter will output the entity now.
Interpretation
/say @e[tag=MC141484]This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
/execute as @e[tag=MC141484] at @s run say @e[distance=..1]This command will first find the entity using the global list but then use the local chunk list to find the entity again, and this time it is not found. This is likely because the chunk is unloaded and therefor has no local entity list.
The bug is, that the entity is not removed from the global entity list.If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23x23 area around it are unloaded.
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Steps to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}- Run the following commands
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Both should output the entity.
- Teleport about 10 chunks away.
/tp ~160 ~ ~- Run the commands again
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Only the latter will output the entity now.
Interpretation
/say @e[tag=MC141484]This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
./execute as @e[tag=MC141484] at @s run say @e[distance=..1]This command will first find the entity using the global list but then use the local chunk list to find the entity again, and this time it is not found. This is likely because the chunk is unloaded and therefor has no local entity list.
The bug is, that the entity is not removed from the global entity list.
If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23x23 area around it are unloaded.
Entitiesonly get removed from the global list if a 23x23 chunk area around them isunloadedEntities stay on the global list even when the chunk unloaded
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Steps to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}- Run the following commands
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Both should output the entity.
- Teleport about 10 chunks away.
/tp ~160 ~ ~- Run the commands again
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Only the latter will output the entity now.
Interpretation
/say @e[tag=MC141484]This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
./execute as @e[tag=MC141484] at @s run say @e[distance=..1]This command will first find the entity using the global list but then use the local chunk list to find the entity again, and this time it is not found. This is likely because the chunk is unloaded and therefor has no local entity list.
The bug is, that the entity is not removed from the global entity list.
If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23x23 area around it are unloaded.
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Though that might only be the case when the player leaves the chunks. By changing the render distance I was also able to get entities staying on the list which were over 30 chunks from the next loaded chunk.
Steps to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}- Run the following commands
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Both should output the entity.
- Teleport about 10 chunks away.
/tp ~160 ~ ~- Run the commands again
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Only the latter will output the entity now.
Interpretation
/say @e[tag=MC141484]This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
./execute as @e[tag=MC141484] at @s run say @e[distance=..1]This command will first find the entity using the global list but then use the local chunk list to find the entity again, and this time it is not found. This is likely because the chunk is unloaded and therefor has no local entity list.
The bug is, that the entity is not removed from the global entity list.
If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23x23 area around it are unloaded.
![[Mod] Michael Wobst](../../../data/avatars/users/37868.png){kind=small}
relates to
![[Mod] Neko](../../../data/avatars/users/92901.png){kind=small}
relates to
relates to
relates to
![[Mod] violine1101](../../../data/avatars/users/92858.png){kind=small}
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Though that might only be the case when the player leaves the chunks. By changing the render distance I was also able to get entities staying on the list which were over 30 chunks from the next loaded chunk.
Steps to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}- Run the following commands
/execute as @e[tag=MC141484] at @s run say @e[distance=..1] /say @e[tag=MC141484]Both should output the entity.
- Teleport about 10 chunks away.
/tp ~160 ~ ~- Run the commands again
s@e[tag=MC141484] at @s run say@e[distance=..1] /say @e[tag=MC141484]Only the latter will output the entity now.
Interpretation
/say @e[tag=MC141484]This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
./execute as @e[tag=MC141484] at @s run say @e[distance=..1]This command will first find the entity using the global list but then use the local chunk list to find the entity again, and this time it is not found. This is likely because the chunk is unloaded and therefor has no local entity list.
The bug is, that the entity is not removed from the global entity list.
If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23x23 area around it are unloaded.
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Though that might only be the case when the player leaves the chunks. By changing the render distance I was also able to get entities staying on the list which were over 30 chunks from the next loaded chunk.
Steps to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0
- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}
- Run the following commands
/execute at @e[tag=MC141484] as @e[distance=..1] run say @s /say @e[tag=MC141484]Both should output the entity.
- Teleport about 10 chunks away.
/tp ~160 ~ ~
- Run the commands again
/execute at @e[tag=MC141484] as @e[distance=..1] run say @s /say @e[tag=MC141484]Only the latter will output the entity now.
Interpretation
/say @e[tag=MC141484]This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
./execute as @e[tag=MC141484] at @s run say @e[distance=..1]This command will first find the entity using the global list but then use the local chunk list to find the entity again, and this time it is not found. This is likely because the chunk is unloaded and therefor has no local entity list.
The bug is, that the entity is not removed from the global entity list.
If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23x23 area around it are unloaded.
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Though that might only be the case when the player leaves the chunks. By changing the render distance I was also able to get entities staying on the list which were over 30 chunks from the next loaded chunk.
Steps to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0
- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}
- Run the following commands
/execute at @e[tag=MC141484] as @e[distance=..1] run say @s /say @e[tag=MC141484]Both should output the entity.
- Teleport about 10 chunks away.
/tp ~160 ~ ~
- Run the commands again
/execute at @e[tag=MC141484] as @e[distance=..1] run say @s /say @e[tag=MC141484]Only the latter will output the entity now.
Interpretation
/say @e[tag=MC141484]This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
./execute as@e[tag=MC141484] at @s run say @e[distance=..1]This command will first find the entity using the global list but then use the local chunk list to find the entity again, and this time it is not found. This is likely because the chunk is unloaded and therefor has no local entity list.
The bug is, that the entity is not removed from the global entity list.
If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23x23 area around it are unloaded.
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Though that might only be the case when the player leaves the chunks. By changing the render distance I was also able to get entities staying on the list which were over 30 chunks from the next loaded chunk.
Steps to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0
- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}
- Run the following commands
/execute at @e[tag=MC141484] as @e[tag=MC141484,distance=..1] run say @s /say @e[tag=MC141484]Both should output the entity.
- Teleport about 10 chunks away.
/tp ~160 ~ ~
- Run the commands again
/execute at @e[tag=MC141484] as @e[tag=MC141484,distance=..1] run say @s /say @e[tag=MC141484]Only the latter will output the entity now.
Interpretation
/say @e[tag=MC141484]This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
./execute at @e[tag=MC141484] as @e[tag=MC141484,distance=..1] run say @sThis command will first find the entity using the global list but then use the local chunk list to find the entity again.
Only if the entity can be found on both lists it will produce an output.The bug is, that the entity is not removed from the global entity list.
If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23x23 area around it are unloaded.
![[Mojang] Bartosz Bok](../../../data/avatars/users/10122.svg){kind=small}
[Mojang] Bartosz BokEntities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23x23 area around them are unloaded.
Though that might only be the case when the player leaves the chunks. By changing the render distance I was also able to get entities staying on the list which were over 30 chunks from the next loaded chunk.
Stepsto reproduceSetup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0
- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}
- Run the following commands
/execute at @e[tag=MC141484] as @e[tag=MC141484,distance=..1] run say @s /say @e[tag=MC141484]Both should output the entity.
- Teleport about 10 chunks away.
/tp ~160 ~ ~
- Run the commands again
/execute at @e[tag=MC141484] as @e[tag=MC141484,distance=..1] run say @s /say @e[tag=MC141484]Only the latter will output the entity now
.Interpretation
/say @e[tag=MC141484]This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
./execute at @e[tag=MC141484] as @e[tag=MC141484,distance=..1] run say @sThis command will first find the entity using the global list but then use the local chunk list to find the entity again.
Only if the entity can be found on both lists it will produce an output.The bug is, that the entity is not removed from the global entity list.
If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23
x23 area around it are unloaded.The bug
Entities keep being accessible via the global entity list, even after the chunk they belong to appears to be unloaded (blocks can't be accessed with commands).
It appears that the entities only get removed from the global list once all chunks in a 23×23 area around them are unloaded. Though that might only be the case when the player leaves the chunks. By changing the render distance I was also able to get entities staying on the list which were over 30 chunks from the next loaded chunk.How to reproduce
Setup: Superflat world, render distance 8.
- Teleport away from the spawn
/tp 10000 100 0- Summon a tagged armor stand
/summon minecraft:armor_stand ~ ~ ~ {Tags:[MC141484]}- Run the following commands
/execute at @e[tag=MC141484] as @e[tag=MC141484,distance=..1] run say @s /say @e[tag=MC141484]→ Both should output the entity
- Teleport about 10 chunks away.
/tp ~160 ~ ~- Run the commands again
/execute at @e[tag=MC141484] as @e[tag=MC141484,distance=..1] run say @s /say @e[tag=MC141484]→ Only the latter will output the entity now
Interpretation
/say @e[tag=MC141484]This command will find entities using the global entity list, so it will be able to find the entity when it is on there.
/execute at @e[tag=MC141484] as @e[tag=MC141484,distance=..1] run say @sThis command will first find the entity using the global list but then use the local chunk list to find the entity again. Only if the entity can be found on both lists it will produce an output.
The bug is, that the entity is not removed from the global entity list.
If you keep moving further way and keep checking with the global entity list command, you will find that the entity will get removed from the global list once all chunks in a 23×23 area around it are unloaded.
![[Mojang] Nathan Adams](../../../data/assets/gravatar/dinnerbone.png){kind=small}
![[Mod] GoldenHelmet](../../../data/avatars/users/18951.svg){kind=small}
relates to
This might also be related to MC-141484.
Can the clones be found with a global entity selector?
What I mean by that, is a selector which does not contain a distance. Because when you use the distance in a selector, the game will usually use the chunks entity list, rather then the global one.
I had the same thing happen in 18w50a after teleporting around a bit. Wasn't able to find a good way to reproduce it though.
It seems that under certain conditions entity end up not being updated correctly on all lists.
When entering [distance=..n] in an entity selector, it will likely use the chunk-wise entity list.
Player selectors may prefer the global player list in most cases though.
So if the player entity is missing on the chunk-wise list it won't be found by the entity selector, but would still be found by the player selector.
Maybe try @e[type=player] without a distance and see if that is able to find the player. That would further confirm that it is caused by the lookup on the local list.
Oh yeah and MC-141484 might be related.
[Helper] Johnibur Thank your for confirming 
So yeah MC-141484 is related, MC-142022 as well.
They all describe situations where entities are only on the global list and issues that likely result from this.
![[Helper] Johnibur](../../../data/avatars/users/28381.png){kind=small}
In order to reproduce it, you have to relog outside of any permanently loaded chunks (outside of spawn chunks for instance), in any dimension. Only if, it will duplicate the mobs around you upon reloading. They can sometimes be invisible, or be inside each others, but the logs will complain about entities with same uuid.
This issue relates to how entities are being tracked upon loading chunks, especially duped entities only appear on the global entity list MC-141484.
This issue is the same as MC-138871, MC-138919, and causes the spawning "keeping entities with same uuid." in the logs MC-95649.
A workaround for this issue is to /forceload the chunks where you reload or go to/from the Nether or the End.
Spawning rate is working fine. I'm using the scoreboard to count the number of hostile mobs currently loaded and at anytime it's close to the actual mob cap (which is 70 per 289 unique chunks loaded). Still sometimes I can see barely no mobs around. So what's happening? I investigated and by teleportation to random mobs I found out they are standing far away where no player is, not even the chunks are loaded. Still they register against the mob cap. I think it's related to the snapshot entities tracking capabilities which are very problematic at the moment, causing mobs duplication, or entities still tracked even after the chunks have been unloaded. MC-141484
This is still an issue, described in MC-138919. Actually I think it's not related to traveling between dimensions, but more to chunks loading, as it can happen everywhere outside of spawn chunks upon reloading. MC-138871
When happening, this produces a "keeping entity with same uuid" warning in the logs MC-95649. It's a major issue with how the entities are tracked. The duped entities can be tracked on the global entity list, but they don't register against the local one. The difference between global and local is that in order to access the local one, you need to specify a distance parameter in your selector. MC-141484
I've done extensive testing with the same setup I used in 19w09a. Then I easily got the "Keeping entity with UUID" message in game output and a lot of both invisible and visible duplications to the point where the game barely was able to load because of all the entities created through deaths, relogs, teleportation and moving between dimensions. In 19w12b I was unable to recreate the bug at all even though I really stress tested with many more entities causing much more lag towards the end of the session. I think MC-141484 being fixed might have solved this one.
The resolution for MC-141484 may be what your issue is.
Relates to
MC-142022andMC-138871.Confirmed for 19w09a.
Confirmed for 19w11b.
It seems that in latest snapshot either both commands give output or none of them does. Actual distance to teleport or walk before chunk unloads is bit higher than described though (>300 for chunk radius 8).
It still happens the same in 19w11b.
I think I described it badly, as one needs ignore the name in front in the outputs.
It will output the armor stand as long as it is on the global list, but only also have a second "Armor Stand" behind it if it is also on the local list.
When running the command:
The output before teleporting is:
The output after teleporting is:
That the name in front shows that is was found on the global list (aka @e[tag=MC141484]), while the name in the back shows that it is on the local list (aka at @s say @e[distance=..1]). Sorry for the confusion.
Thank you for looking into this!
@edit I replaced the commands in the post to only have an output if it is on the list. So now there is really no output for the command when the entity isn't on both lists.
@boq This ticket shows that entities can now be accessed under certain distance conditions, even if they are located in a chunk which is currently unloaded. For instance, you can access the entity, but not the block it is standing in, because the chunk is not loaded. Is that intended?
It is marked as confirmed and has a dev comment, so I would assume it's not intended. It's also inconsistent, you can do some things with those entities, but not many others.
Just for clarity, chunk with armor stand was not unloaded (it's border one), but function to query for all entities was missing check if containing chunk was ticking.
Hmm.. Isn't the non-ticked border supposed to be two chunks wide?
Also when I tried accessing the blocks (e.g. setblock) in the chunk where the armorstand was I would get a message saying "That position is not loaded" while the armorstand was still found via the global list.
You guys changed a lot about chunkloading recently so maybe my understanding of what's a border chunk is a bit off. Is there a new way of non-ticked chunks that are also not accessible?
Either way for 19w12b I can confirm this issue fixed, thank you
That required bit more explanation, so I made some graphs (using debug method obfuscated in 19w12b as 'void uq.a(String)', which dumps information about loaded chunks to file). Note that it is implementation detail and subject to change.
Every loaded chunk has few values associated with them:
When requesting chunk with given status, appropriate ticket level is required - for example, accessing chunk with status 'full' requires ticket level 33 or lower (if loading or generation is allowed, game will add 'unknown' ticket and provide neighboring chunks with lower status/higher ticket levels). Querying chunk for entities or blocks requires full chunks, so that explains why search failed (after teleporting, chunk with armor stand has ticket level 36, even though it already has 'full' chunk status - it's one way relationship).
On loading level values look like this:
That yellow "archipelago" to left is due to chunk being saved as full on disk. That does not mean chunk is queryable or that it's "full chunk", since that still depends on ticket level (which is not stored). You can also see that general ticking structure remains unchanged from previous versions.
Now, after teleporting to armor stand and back, loaded chunks look like this:
Now there is rather big purple area on third plot. Dump categorizes this as "border chunk" - they were loaded before, so they are stored in-memory as full chunks (algorithm never downgrades full chunks to non-full ones) and "border" is lowest full chunk status. So entities from that are still kept in global list (and in internal chunk list), but they are not accessible due to ticket level.
So simplest solution was to filter entities based on ticket level of chunk they are in. Though it seems I made mistake and required entity ticking level (31) instead of just border chunk (33), so chunks loaded with forceload (ticket level 32) are not accessible right now (partially
MC-146470).Note: chunk are dropped from list on ticket level 44. That's also when entities are removed from lists.
[Mojang] Bartosz Bok Thank you very much for taking the time to explain it!
We are currently trying to wrap our head around it and currently conduct a few tests to get a clearer picture
In any case, have a nice weekend and thank you again for your effort!
[Mojang] Bartosz Bok Awesome! This explanation helps so much to get a better idea of how it works.
Not that I fully understand it yet, but many things we observed in the snapshots make more sense now.
I had situations where a 5x5 of chunks kept being accessible after moving back and forth over a chunk border with server lag. Probably the ticket level of 31 of the player was not reset for a chunk at the border of the area the players ticket value is applied to.
The command block tool to visualize the accessibility of chunks broke two snapshots ago for reasons I have yet to figure out, so I didn't test this in the latest snapshots yet.
Rephrased from my current understanding:
One thing I don't get about the graphics you posted is with the full chunk status. The red border (I assume that is the full chunk status "ticking") is only one chunk thick. But in game I still observe a two chunk thick border where entities don't get ticked but scheduled ticks are processed.
During testing I also did observe that I'm not able to access entities in the chunks without entity processing around the player loaded chunks. That's probably also because of what you described about the required ticking level for the entity list filter being off by a bit.
There is a lot more details I can't completely get my head around yet. It will surely take a while to become familiar with this new system.
Again thank you for taking the time to explain it here in such detail, that helps a lot!
Bit more explanation on ticket levels.
They are now core of chunk loading - they determine which chunks are loaded, how far in generation they should be and what full chunk (i.e. ticking) status they have.
Ticket level is determined based on level of neighboring chunks. Every chunk can also have tickets attached that set upper limit to ticket level of chunk (there can be multiple ones per chunk, but usually we only care about ticket with lowest level).
In other words: every loaded chunk has ticket level and zero or more tickets. Tickets are "sources" of ticket values, which spread to neighboring chunks.
Few key values:
Here is list of ticket level to chunk and full chunk statuses:
levels.txt
So now for examples:
Freshly loaded flat world:
grass.txt
One spawn ticket, few player tickets from view radius 8 and few 'unknowns' from random ticks (they are not permanent and will be removed on next tick). Note that even though chunk may have player ticket with level 31, actual ticket level might be lower if there are lower tickets nearby.
Freshly loaded flat world with sandstone on top:
sand.txt
Interesting thing happens around levels 35-38 - there are fully generated chunks, but still in protochunk form (no ticking status). During worldgen game tries to find proper spawn position. Since all surface blocks are sandstone, algorithm probes every chunk in square with radius of 16. Testing for blocks requires fully generated chunks, but after reload ticket level is not enough to promote to full chunk. So ticket level determines generation status, but not the other way.
Forced chunk
force.txt
Single ticket of level 32 + neighboring generation.
Now, couple other things:
Things start to get more clear. Especially levels.txt
helps a lot 
Paraphrasing again to avoid misunderstandings:
So some actions can place tickets on chunks to force them to load, generate (different levels) or load the surroundings.
You named a few things that can place tickets and what ticket level they have, like players and spawn chunks. I assume random ticks and block updates probably both cause (temporary) ticket level 33, judging by the level of the "unknown"s?
And then there is actions that only run if there is a certain ticket level in the chunk.
What I currently got from testing:
In a few weeks I will have time to test these things in more detail.
To the couple of other things
MC-141483)About the 2 wide ticking border
After reading this second part of the explanation, I'm pretty sure what I described is due to ticket level 33 (border) is being handled differently than ticket level 34 (border).
This means
MC-141482is the same behaviour as the 2 wide border I described for the chunks around player placed tickets.It's about /forceload "loading" more chunks than specified. Forceloading a chunk currently makes it's neighbours accessible as well.
Also the list of required levels above pretty much describes the observed already. Most things require <=33 (so a level classified as "border") rather than <=32 (which would be "ticking").
To test this behaviour:
1. Forceload a chunk
2. Take note of coordinates of any block in a chunk next to the forceloaded chunk.
3. Get far enough away for it to not be affected by the players ticket level
4. Run this command on the coordinates you took note of:
/execute unless block <x> <y> <z> air{N:O} run say chunk is loadedThe command only has an output if the blocks in the chunk can be accessed.
It will produce an output for chunks next to a forceloaded chunk.
Obviously it will also produce an output for chunks next to the "ticking" chunks caused by a players tickets.
Alternatively you can place a repeating command block with a say command in the chunk. That only runs if scheduled ticks get processed, so if you still get outputs that indicates that ticket level 33 still runs scheduled ticks. (and it does)
I you are looking at chunk loading logic and entity lists these two issues might also interest you:
MC-141485(change in size of spawn chunks because of the recent chunk loading changes, may be WAI)MC-108469(age old issue about chunk wise entity lists not getting updated correctly, reproduction is partially broken in 19w12b due toMC-146470, see latest comment)It seems that double BORDER layer may not be correct and caused by "magic value" at one point was changed from 32 to 33 - some places might not be updated. Anyway, values posted here are probably not final.
Also, right now only requirement for block entity ticking is level 33, so yes, inner layer of border chunks will tick. This is also probably a bug. Though it seems that random tick and other things work only on level 34.
I'm not sure if `/execute unless block` is proper test for ticking chunk, command block method seems like better way of checking for it.
And yes, unknown tickets are from random ticks, or more specifically, any access to chunk (players also create one when checking for blocks around, but only lowest ticket is shown in dump).
Fair point, the `/execute unless block` only detects if commands got the proper clearance for the chunk, which may or may not be the same as ticking.
I mentioned the command first, because this is what I used to query and display the status of chunks in game (which is how I noticed it in the first place). The command block method doesn't work well for that, as the block already needs to be in the chunk.
A `/getticketlevel <x> <z>` would be really useful for debugging *hint**hint*
A /getticketlevel or similar would be awesome!
That'd be so extremely helpful.
Thank you to both of you for additions/explanations
For anyone interested in internals of chunk loading, `/debug report` in 1.14.4-pre produces tables similar to ones attached here.