From b8ace17b7c76ffdfa7814a23ba4e40b2a1cc5ac1 Mon Sep 17 00:00:00 2001
From: Geoff Bourne <itzgeoff@gmail.com>
Date: Fri, 10 Apr 2020 15:33:16 -0500
Subject: [PATCH 1/2] ci: ignore non-amd64 branches

---
 .circleci/config.yml | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 42b4466d..1c98efc9 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -14,4 +14,9 @@ workflows:
   version: 2
   build:
     jobs:
-      - minecraft_server
+      - minecraft_server:
+          filters:
+            branches:
+              ignore:
+                - armv7
+                - multiarch

From 791000508679db8c3e46935bbd08b7c5ed96a56f Mon Sep 17 00:00:00 2001
From: Geoff Bourne <itzgeoff@gmail.com>
Date: Sat, 11 Apr 2020 08:43:17 -0500
Subject: [PATCH 2/2] Added option to use Aikar's flags

---
 README.md                 |  6 ++++++
 start-minecraftFinalSetup | 29 +++++++++++++++++++++++++++--
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index afe1a095..25459e12 100644
--- a/README.md
+++ b/README.md
@@ -1040,6 +1040,12 @@ To enable remote JMX, such as for profiling with VisualVM or JMC, add the enviro
 
     -e ENABLE_JMX=true -p 7091:7091
 
+### Enable Aikar's Flags
+
+[Aikar has does some research](https://aikar.co/2018/07/02/tuning-the-jvm-g1gc-garbage-collector-flags-for-minecraft/) into finding the optimal JVM flags for GC tuning, which becomes more important as more users are connected concurrently. The set of flags documented there can be added using
+
+    -e USE_AIKAR_FLAGS=true
+
 ### HTTP Proxy
 
 You may configure the use of an HTTP/HTTPS proxy by passing the proxy's URL via the `PROXY`
diff --git a/start-minecraftFinalSetup b/start-minecraftFinalSetup
index a0ee38dd..be80eeee 100644
--- a/start-minecraftFinalSetup
+++ b/start-minecraftFinalSetup
@@ -43,7 +43,7 @@ fi
 log "Checking for JSON files."
 JSON_FILES=$(find . -maxdepth 1 -name '*.json')
 for j in $JSON_FILES; do
-  if [[ $(cat $j | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//') == "" ]]; then
+  if [[ $(cat "$j" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//') == "" ]]; then
     log "Fixing JSON $j"
     echo '[]' > $j
   fi
@@ -61,7 +61,7 @@ fi
 for c in /config/*
 do
   if [ -f "$c" ]; then
-    log Copying configuration `basename "$c"`
+    log Copying configuration $(basename "$c")
     cp -rf "$c" /data/config
   fi
 done
@@ -115,6 +115,31 @@ if isTrue ${ENABLE_JMX}; then
   log "JMX is enabled. Make sure you have port forwarding for ${JMX_PORT}"
 fi
 
+if isTrue ${USE_AIKAR_FLAGS}; then
+  # From https://aikar.co/2018/07/02/tuning-the-jvm-g1gc-garbage-collector-flags-for-minecraft/
+  JVM_OPTS="${JVM_XX_OPTS}
+  -XX:+UseG1GC -XX:+ParallelRefProcEnabled
+  -XX:MaxGCPauseMillis=200
+  -XX:+UnlockExperimentalVMOptions
+  -XX:+DisableExplicitGC
+  -XX:-OmitStackTraceInFastThrow
+  -XX:+AlwaysPreTouch
+  -XX:G1NewSizePercent=30
+  -XX:G1MaxNewSizePercent=40
+  -XX:G1HeapRegionSize=8M
+  -XX:G1ReservePercent=20
+  -XX:G1HeapWastePercent=5
+  -XX:G1MixedGCCountTarget=8
+  -XX:InitiatingHeapOccupancyPercent=15
+  -XX:G1MixedGCLiveThresholdPercent=90
+  -XX:G1RSetUpdatingPauseTimePercent=5
+  -XX:SurvivorRatio=32
+  -XX:MaxTenuringThreshold=1
+  -Dusing.aikars.flags=true
+  -Daikars.new.flags=true
+  "
+fi
+
 mcServerRunnerArgs="--stop-duration 60s"
 
 if [[ ${TYPE} == "FEED-THE-BEAST" ]]; then