Uploaded image for project: 'Minecraft: Java Edition'
  1. Minecraft: Java Edition
  2. MC-135289

Water updates extremely slow (server lag)

    XMLWordPrintable

    Details

    • Type: Bug
    • Status: Open
    • Resolution: Unresolved
    • Affects Version/s: Minecraft 1.13, Minecraft 18w30b, Minecraft 18w31a, Minecraft 18w32a, Minecraft 18w33a, Minecraft 1.13.1-pre1, Minecraft 1.13.1-pre2, 1.15.1, 20w28a, 20w29a, 1.16.2 Pre-release 1, 1.16.2 Release Candidate 2, 1.16.2, 1.16.3
    • Fix Version/s: None
    • Confirmation Status:
      Confirmed
    • Category:
      Performance
    • Mojang Priority:
      Important

      Description

      The bug

      Server-side water updates seem to be roughly 10x slower than in 1.12.
      The comparison between 1.12 and 1.13 can be seen in this video by gnembon.

      Test to exhibit this behavior:

      1. Create a flat world.
      2. Execute /fill ~-100 ~ ~ ~100 ~ ~ water
      3. Wait for the water to flow completely.
      4. Execute /fill ~-100 ~ ~ ~100 ~ ~ air

      When the water is removed I recorded a peak at 81 mspt on 1.13 and a peak at (roughly) 8 mspt on 1.12.2.

      This makes flushing mob farms unusable: on my survival world, I get peaks > 150 mspt.

      The mspt measurment on 1.12 is a bit tricky as there is no way to measure it properly:
      I used /forge tps from Forge mod loader to measure it.

      Slow down summary

        1.12 1.13 18w33a 1.13.1-pre2 1.15.1 20w27a
      create water 4 34 20 14 19 10
      remove water 8 81 24 18 31 16

        Attachments

        1. 2018-07-30_23.13.45.png
          2018-07-30_23.13.45.png
          1.01 MB
        2. 2018-07-30_23.02.25.png
          2018-07-30_23.02.25.png
          733 kB
        3. 2018-08-15_22.07.50.png
          2018-08-15_22.07.50.png
          848 kB
        4. 2020-07-02_22.26.30.png
          2020-07-02_22.26.30.png
          795 kB
        5. water lag test.zip
          410 kB

          Issue Links

            Activity

              People

              Assignee:
              Unassigned Unassigned
              Reporter:
              csdt Florian
              Votes:
              72 Vote for this issue
              Watchers:
              36 Start watching this issue

                Dates

                Created:
                Updated:
                CHK: