Merge pull request #1 from jiriks74/devel

Add Aikar's flags, better comments, etc

README.md

@@ -31,21 +31,13 @@ version="1.12.2"
 
 5. Select how much memory you want your server to use ***(in megabytes)***:
   ```bash
-initMem="1500M" #1.5G
-maxMem="8000M" # 12G
+mem="8000M"
 ```
 
-6. Modify server parameters to your liking:
-  ```bash
-mc_launchoptions="-nogui"
-```
+6. Allow executing ov the script with `chmod +x start.sh`
+7. Run the script with `./start.sh`
 
-7. Add some jvm (java) parameters to your liking ***(memory is set above, do not add it here)***:
-  ```bash
- java_launchoptions=""
- ```
- > **Note**
- >
- > If you use quite old versions of minecraft you should change the defaults under the line above
- 
-8. Run the script with `./start.sh`
+## Default JVM flags used
+
+By default this script uses [Aikar's Flags](https://docs.papermc.io/paper/aikars-flags). It's set up so that it automatically modifies them if over
+12GB of memory is set for the server so you shouldn't need to change them unless you want to swap them out for something else.

start.sh

@@ -4,6 +4,7 @@
 #                                              by jiriks74                                                  #
 #                             https://github.com/jiriks74/start_papermc.sh                                  #
 #  This script is under GPLv3, if you want to distribute changes you have to do so under the same license   #
+#                            and acknowledge the original script and author.                                #
 #############################################################################################################
 
 ############
@@ -16,32 +17,50 @@
 # and change the version below.                                    #
 # I am not responsible for any loss of data                        #
 # !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! #
-# If enough people request it (or someone creates a PR) I'll add this functionality
+# If enough people request it (or someone creates a PR) I'll add the functionality to migrate versions
 version="1.19.3"
-# Leave blank to use the latest build
+# Leave blank to use the latest build (auto updates on every run)
 select_build=""
 
+#
 # Memory settings
-initMem="2000M" # Minimum memory used
-maxMem="6000M" # Maximum memory allowed to be used
+#
+# !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! #
+# Do not allocate all of your available memory on a shared host! #
+# Minecraft (and Java) needs to have more memory than the Xmx    #
+# parameter (maxMem below). You should set it at least 1500M     #
+# lower than your available memory if you're running just the    #
+# minecraft server.                                              #
+# !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! #
+mem="2000M"
+
+
+
+# ------------------------------------------------
+# You shouldn't need to change anything below this
+# ------------------------------------------------
 
 # Options for the server
 mc_launchoptions="-nogui"
 
-# G1GC settings - leave the defaults if you're unsure
-g1HeapMem="32M" # Memory used by G1
-g1NewSize="20" # In %
-g1Reserve"20" # In %
-umaxGCpause="50" # In millis
+if [[ "${mem%M}" -gt 12000 ]]; then
+  G1NewSize=40
+  G1MaxNewSize=50
+  G1HeapRegionSize=16M
+  G1Reserve=15
+  InitiatingHeapOccupancy=20
+else
+  G1NewSize=30
+  G1MaxNewSize=40
+  G1HeapRegionSize=8M
+  G1Reserve=20
+  InitiatingHeapOccupancy=15
+fi
 
-# Aditional options for the java runtime
-java_launchoptions=""
+# Aikar's flags are used by default
+# See https://docs.papermc.io/paper/aikars-flags
+java_launchoptions="-Xms$mem -Xmx$mem -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1NewSizePercent=$G1NewSize -XX:G1MaxNewSizePercent=$G1MaxNewSize -XX:G1HeapRegionSize=$G1HeapRegionSize -XX:G1ReservePercent=$G1Reserve -XX:G1HeapWastePercent=5 -XX:G1MixedGCCountTarget=4 -XX:InitiatingHeapOccupancyPercent=$InitiatingHeapOccupancy -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=5 -XX:SurvivorRatio=32 -XX:+PerfDisableSharedMem -XX:MaxTenuringThreshold=1 -Dusing.aikars.flags=https://mcflags.emc.gs -Daikars.new.flags=true"
 
-# Change the defaults if you use older version of minecraft or just want to use something else
-java_launchoptions="-Xms$initMem -Xmx$maxMem -XX:G1HeapRegionSize=$g1HeapMem -XX:+UseG1GC -XX:G1NewSizePercent=$g1NewSize -XX:G1ReservePercent=$g1Reserve -XX:MaxGCPauseMillis=$maxGCpause  $java_launchoptions"
-
-# You shouldn't need to change anything below this line
-# -----------------------------------------------------
 
 # Api url
 url="https://api.papermc.io/v2/projects/paper/versions/$version/builds"