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  1. Minecraft: Java Edition
  2. MC-17630

Zombie pathfinding to unreachable targets causes server lag



    • Icon: Bug Bug
    • Resolution: Fixed
    • Minecraft 16w15b
    • Snapshot 13w23b, Minecraft 1.6, Minecraft 1.6.1, Minecraft 1.6.2, Minecraft 1.6.4, Minecraft 13w38a, Minecraft 1.7.4, Minecraft 14w04b, Minecraft 14w05b, Minecraft 14w06a, Minecraft 14w06b, Minecraft 14w07a, Minecraft 14w08a, Minecraft 1.7.5, Minecraft 1.8.1-pre3, Minecraft 15w43b, Minecraft 16w06a, Minecraft 1.9, Minecraft 1.9.1 Pre-Release 3, Minecraft 1.9.1, Minecraft 1.9.2, Minecraft 16w14a
    • Confirmed


      As some new commenters do not bother to read older comments, a link back to the buried earlier comment with my analysis (in short, a possible reason is already known): Summed up in this comment.

      Workaround: Using Forge (files.minecraftforge.net) or the snapshot 13w39a+

      For clarity, let me rewrite this:


      This bug appears when a large number of zombies cannot successfully calculate a safe path to their target. Severe lag in either single or multiplayer results as well as time moving jumping forward/backward. The only work-around is to kill the zombies, create a path for them, or switch to peaceful mode. Avoiding the night by sleeping may also work. This is especially noticeable around villages due to the number of zombie that appear and their intended targets (villagers) not being reachable.


      While protecting a village (building walls and putting torches up) a zombie siege event occurs, very often, causing extreme lag.

      Could be conflicting code between zombie generation and villager reaction exacerbating each other. The more villagers, the more zombies, the more lag.

      ----------- From MC-18865 ----------------------------------------------------------------

      I am not sure if all these factors are actually relevant, but here we go:

      /gamerule mobGriefing false
      Hard difficulty
      Villagers inside a house
      Zombies trying to break in (difficulty is set to hard, so they would try to break the door, but /gamerule doesn't let them)

      These things MIGHT be related to the issue. I get really bad delay on picking items, killing mobs and even brewing.

      NOTE: this is on SINGLE PLAYER, clearly an internal server problem.
      NOTE2: when I kill all the zombies, the delay is gone. There is probably something wrong with the new zombie system as well.

      ---------------------------------------------------------------- ----------------------------------------------------------------
      Emphasized the analysis of Markku:

      As some new commenters do not bother to read older comments, a link back to the buried earlier comment with my analysis (in short, the reason is already known):


        1. 1.6.2zombielag.png
          584 kB
        2. 2013-09-25_20.55.59.png
          167 kB
        3. 4x4 unreachable causing lag.jpg
          4x4 unreachable causing lag.jpg
          162 kB
        4. crash-2013-06-15_12.54.14-client.txt
          8 kB
        5. day.png
          636 kB
        6. Minecraft Log.txt
          11 kB
        7. night.png
          318 kB
        8. Pathfinding lagtest.zip
          384 kB
        9. Ultra NormalCore.zip
          7.13 MB
        10. Zombie Platform.jpg
          Zombie Platform.jpg
          194 kB
        11. zombie-siege-lag-world.zip
          4.51 MB



            Unassigned Unassigned
            lorenmj Loren Johnson
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