Paper: Multiple ender dragons in the end when playing survival

[nikhiljha]

What behaviour is expected:

1 Ender Dragon

What behaviour is observed:

4 Ender Dragons

Steps/models to reproduce:

1. Open a new Paper 1.14.3 world.
2. Go to the end.

Plugin list:

None

Paper build number:

131

Anything else:

This has also been reproduced by LoXR and barty on Discord.

[JoelDeadMach]

Same

[robertoccu]

Same in our server. Only one boss bar but multiple dragons. When killed, more appeared, but no one spawned the egg or open the portal.

We unload the world (Multiverse). Some hours later loaded it and only was one dragon. Killed it and it opened the portal, end gateway and spawned the egg.

Spawned one with Ender Crystals and killed it. All normal and other end gateway.

Some minutes later without doing anything, other Dragon spawned, without boss bar. When killed, no portal was opened.

Build 131

[JOO200]

I had this issue with 1.12.2. one problem could be that the enderdragon moves into an unloaded chunk. The vanilla part from the server detects the missing ender dragon (unloaded chunk -> enderdragon dead?) And causes the respawn of a new dragon.

[Aurelien30000]

I can confirm this issue in 1.12.2.

[clrxbl]

Can confirm this issue on Paper 1.14.2.

[robertoccu]

Today two more spawned. One at the morning and another some hours (and one server reset) after.

Later I check the logs. This appears, but I don't know if at the exact moment. I will check next time:
Build 134

[BillyGalbreath]

I'd like some more details. Could you please attach a timings report so I can see all your server config settings? I have a feeling this is caused by view distance being too low, or keep spawn loaded is disabled, etc

[robertoccu]

Timings: https://timings.aikar.co/?id=2a1f0accca1a4a6a9ff138212122ac0c (yes, that timings are a mess. We think that is ChunkAsync using all of our CPU)
A difference compared to yesterday: I reduced view-distance from 8 to 6 and added ViaVersion.

Today no dragons spawned, but tps were higher than yesterday. Maybe is something related between end loading, dragon alive check and low tps.

[Spzatak]

confirming this issue on 1.14.4

[electronicboy]

Any idea if this is replicable in spigot/vanilla? You can also disable the legacy ender dragon check

[hanss314]

Can confirm on 1.14.4

[ispeaknousa]

Multiple appeared, I found the one attached to the health bar, saw it disappear while on the bedrock block, then slowly the others started to also disappear.

When there was only one left, although the health bar stayed the same while hitting it, I got the following:

No egg, no portal, then the others reappeared.

1.14.4

[s1h4d0w]

1.14.4 here, same issue. New server running for about a week now.

PaperMC-176 on Ubuntu Server 18.04.3
Timings: https://timings.aikar.co/?id=bb2293d2b5a44f51b34d8d02c3bfdea1

Plugins: AntiCurse, ArmoredElytra, AuthMe, AutoMessager, BetterRTP, ChatReaction, ChopTree2, ClearLag, CoreProtect, CrazyEnchantments, DeathCoordinates, DynamicShop, Essentials, EssentialsChat, EssentialsSpawn, FastAsyncWorldEdit, GriefPrevention, HolographicDisplays, InfernalMobs, Item2Chat, Jobs, JoinMessagePlus, JukeBox, LuckPerms, Matrix, MineableSpawners, Multiverse-Core, MyCommand, NoteBlockAPI, OnTime, PhantomSMP, ProtocolLib, QuickShop, ServerListPlus*, SkinsRestorer, SuperbVote, UltraCosmetics, Vault, Votifier, WorldBorder, WorldEdit, WorldEditSelectionVisualizer, WorldGuard, WorldGuardExtraFlags

I teleported to the end once as OPed player, then left immediately as I realized I was literally the first one to go there before normal players. Then eventually a player made it to the End and there were maybe 10-20 dragons flying around.

I don't have the exact console output but it said something like this:

[Server thread/INFO]: Scanning for legacy world dragon fight...
[Server thread/INFO]: Found that the dragon has not been killed in this world.
[Server thread/INFO]: Found that there's a dragon still alive (coordinates and stuff).
[Server thread/INFO]: But we didn't have a portal, let's remove it.

Then the player started messaging me in a panic saying there were dozens of dragons. I used killall to remove them, but the boss bar stayed up. I then just spawned a new dragon using spawnmob and that fixed the whole thing.

But reading these replies it seems like more can still spawn.

[PachiMc]

same to me

[Remski01]

https://github.com/PaperMC/Paper/issues/2320#issuecomment-516665981

[NullCase]

Confirmed in Paper-225 (MC: 1.14.4)

• I'd update to latest but for that recent issue about vanishing chunks. Just gonna wait on that one. Idk, paper devs are legit and maybe it's solved already.

[dmodoomsirius]

confirmed with paper-236.

Plugins: AdvancedWarn, ArmorStandEditor, Autorank, BannerMaker, BetterRTP, BlockLocker, BuyRegion, CoreProtect, CS-CoreLib, DeathMessagesPrime, dynmap, Essentials, EssentialsAntiBuild, EssentialsChat, EssentialsGeoIP, EssentialsProtect, EssentialsSpawn, EXPGRadioPlugin, FastLeafDecay, InventoryRollback, MeltDown, MineableSpawners, MobCapture, Multiverse-Core, Multiverse-Inventories, Multiverse-Portals, MysqlEconomyBank, PermissionsEx, PlayerReport, PlotSquared, PluginLibrary, ProtocolLib, Shop, SmoothSleep, StaffPlus, SuperVanish, Vault, WG-GUI, WorldEdit, WorldGuard

Config option in paper.yml scan-for-legacy-ender-dragon at the recommendation of electroniccat was set to false and still have the same issue with them spawning.

steps to reproduce

1. warp to the end
2. kill all the ender dragon's using the killall hostile command
3. warp out of the end.
4. warp back in using essentials commands.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale[bot]]

This issue has been automatically closed because it has not had activity in a long time. If the issue still applies to the most recent supported version, please open a new issue referencing this original issue.