Minecraft
=========

Follow: esxi/vm_template (for mc.lustfield.net)

- /opt -> 20G

1. Create: /usr/local/sbin/msm
2. Create: /etc/init.d/{msm,bungee}
3. update-rc.d {bungee,msm} defaults

.. code-block:: sh

   apt install git default-jre
   apt purge dbus

   git clone https://github.com/msmhq/msm.git /opt/msm-repo

crontab -e::

    # msm-backup
    0 5 * * * /usr/local/sbin/msm all worlds backup >/dev/null
    # msm-logroll
    0 3 * * * /usr/local/sbin/msm all logroll >/dev/null
    # msm-backup-cleanup
    0 5 * * * find /opt/msm/archives -type f -mtime +2 -name '*.zip' -o -name '*.gz' -delete

.. code-block:: sh

   groupadd -g 1011 msm
   useradd -s /bin/dash -u 1011 -g 1011 -d /opt/msm msm


IRC Conversation:

.. code-block:: text

   09:24 <+nbastin> once you get to around 12gb you can really tweak the GC
   09:24 <+Bumbu> I could, but it hasn't come close to approaching it's limit
   09:24 <+nbastin> well mostly the trick is just to tweak the GC to keep everything collected out of old generation
   09:24 <+nbastin> but 8gb is usually not enough to make that work
   09:25 <+nbastin> I'm only using 12g right now, maybe should bump up - 10G is enough for good gc though
   09:25 <+nbastin> something like:
   09:25 <+nbastin> java -Xms12G -Xmx12G -XX\:+UseG1GC -XX\:+UnlockExperimentalVMOptions -XX\:MaxGCPauseMillis=50 -XX\:+DisableExplicitGC -XX\:TargetSurvivorRatio=90 -XX\:G1NewSizePercent=50 -XX\:G1MaxNewSizePercent=80
                    -XX\:InitiatingHeapOccupancyPercent=10 -XX\:G1MixedGCLiveThresholdPercent=50 -XX\:+AggressiveOpts -XX\:+AlwaysPreTouch -XX\:+UseLargePagesInMetaspace -jar paperclip-209.jar nogui
   09:26 <+nbastin> 12G is probably not enough for us, 10G is probably fine for most
   09:27 <+nbastin> if you go too low then your mix of GC params needs to change, because you can starve out your live pools
   09:27 < MiniDigger> if you want a somewhat understandable explanation of these flags (instead of just copy pasting something) read this post https://aikar.co/2018/07/02/tuning-the-jvm-g1gc-garbage-collector-flags-for-minecraft/


   09:57 < MiniDigger> for porting, bungee brings some simple commands, but ideally you want to have a portal plugin
   09:57 < MiniDigger> https://docs.velocitypowered.com/en/latest/users/getting-started.html
   09:57 <+nbastin> oh there we go, it's behind how to install


   10:08 < MiniDigger> for bungee and stuff its important to get some settings right about forwarding UUIDs and IPs to backend servers and securing your backend servers
   10:08 < MiniDigger> https://www.spigotmc.org/wiki/bungeecord-installation/#post-installation


   03:07 <+nbastin> most of them don't change performance that much, but there are a few important ones
   03:08 <+nbastin> max-auto-save-chunks-per-tick, for sure
   03:09 <+nbastin> also there are some you can mess with that have pretty significant impact but change (if only subtly) the behaviour
   03:09 <+nbastin> like grass-spread-tick-rate
   03:09 <+nbastin> max-entity-collisions is good if you have chicken cookers and similar packed areas
   03:11 <+nbastin> if you are not using plugins that hook into hoppers, you really really want to set hopper.disable-move-event to true
   03:11 <+nbastin> that is a big one, esp. as you get more hoppers
   03:12 <+nbastin> also use-faster-eigencraft-redstone, we are using this and it works fine, and is much faster