From 0fca30fcf466630214d2198b524658622900a95a Mon Sep 17 00:00:00 2001
From: Christos Malliaridis <c.malliaridis@gmail.com>
Date: Tue, 29 Oct 2024 13:49:48 +0100
Subject: [PATCH 1/3] Use new unified GC options and remove -XX:+UseG1GC

Starting from JDK 9, G1 is the default GC.

This commit fixes the issue of unrecognized VM options.
---
 solr/benchmark/jmh.sh                         |  2 +-
 solr/bin/solr                                 | 24 +++----------------
 solr/bin/solr.cmd                             | 10 ++------
 solr/bin/solr.in.cmd                          |  5 ++--
 solr/bin/solr.in.sh                           | 10 ++------
 solr/cross-dc-manager/bin/cross-dc-manager    |  7 ------
 .../cross-dc-manager/bin/cross-dc-manager.cmd |  1 -
 solr/prometheus-exporter/bin/solr-exporter    |  7 ------
 .../prometheus-exporter/bin/solr-exporter.cmd |  1 -
 .../pages/system-info-handler.adoc            |  2 --
 ...onitoring-with-prometheus-and-grafana.adoc |  2 +-
 .../pages/taking-solr-to-production.adoc      |  2 +-
 12 files changed, 12 insertions(+), 61 deletions(-)

diff --git a/solr/benchmark/jmh.sh b/solr/benchmark/jmh.sh
index 18f9875da19..2027fd712a4 100755
--- a/solr/benchmark/jmh.sh
+++ b/solr/benchmark/jmh.sh
@@ -52,7 +52,7 @@ echo "running JMH with args: $@"
 #                                                            MRM: I've also seen 15 claimed as a sweet spot.
 
 jvmArgs="-jvmArgs -Djmh.shutdownTimeout=5 -jvmArgs -Djmh.shutdownTimeout.step=3 -jvmArgs -Djava.security.egd=file:/dev/./urandom -jvmArgs -XX:+UnlockDiagnosticVMOptions -jvmArgs -XX:+DebugNonSafepoints -jvmArgs --add-opens=java.base/java.lang.reflect=ALL-UNNAMED"
-gcArgs="-jvmArgs -XX:+UseG1GC -jvmArgs -XX:+ParallelRefProcEnabled"
+gcArgs="-jvmArgs -XX:+ParallelRefProcEnabled"
 
 # -jvmArgs -Dlog4j2.debug 
 loggingArgs="-jvmArgs -Dlog4jConfigurationFile=./log4j2-bench.xml -jvmArgs -Dlog4j2.is.webapp=false -jvmArgs -Dlog4j2.garbagefreeThreadContextMap=true -jvmArgs -Dlog4j2.enableDirectEncoders=true -jvmArgs -Dlog4j2.enable.threadlocals=true"
diff --git a/solr/bin/solr b/solr/bin/solr
index 812972bf6af..edf28bf81b6 100755
--- a/solr/bin/solr
+++ b/solr/bin/solr
@@ -1052,26 +1052,9 @@ if [[ -n ${SOLR_DATA_HOME:-} ]] && [ ! -e "$SOLR_DATA_HOME" ]; then
   exit 1
 fi
 
-# Establish default GC logging opts if no env var set (otherwise init to sensible default)
+# Establish default GC logging opts if no env var set
 if [ -z "${GC_LOG_OPTS}" ]; then
-  GC_LOG_OPTS=('-Xlog:gc*')
-fi
-
-# if verbose gc logging enabled, setup the location of the log file and rotation
-if [ "${#GC_LOG_OPTS[@]}" -gt 0 ]; then
-  if [ "$JAVA_VENDOR" == "OpenJ9" ]; then
-    GC_LOG_OPTS+=("-Xverbosegclog:$SOLR_LOGS_DIR/solr_gc.log" '-XX:+UseGCLogFileRotation' '-XX:NumberOfGCLogFiles=9' '-XX:GCLogFileSize=20M')
-  else
-    # https://openjdk.java.net/jeps/158
-    for i in "${!GC_LOG_OPTS[@]}";
-    do
-      # for simplicity, we only look at the prefix '-Xlog:gc'
-      # (if 'all' or multiple tags are used starting with anything other then 'gc' the user is on their own)
-      # if a single additional ':' exists in param, then there is already an explicit output specifier
-      # shellcheck disable=SC2001
-      GC_LOG_OPTS[$i]=$(echo "${GC_LOG_OPTS[$i]}" | sed "s|^\(-Xlog:gc[^:]*$\)|\1:file=$SOLR_LOGS_DIR/solr_gc.log:time,uptime:filecount=9,filesize=20M|")
-    done
-  fi
+  GC_LOG_OPTS=("-Xlog:gc*:file=$SOLR_LOGS_DIR\solr_gc.log:time,level,tags:filecount=9,filesize=20M")
 fi
 
 if [ "${SOLR_MODE:-}" == 'solrcloud' ]; then
@@ -1202,8 +1185,7 @@ function start_solr() {
 
   # define default GC_TUNE
   if [ -z "${GC_TUNE}" ]; then
-      GC_TUNE_ARR=('-XX:+UseG1GC' \
-        '-XX:+PerfDisableSharedMem' \
+      GC_TUNE_ARR=('-XX:+PerfDisableSharedMem' \
         '-XX:+ParallelRefProcEnabled' \
         '-XX:MaxGCPauseMillis=250' \
         '-XX:+UseLargePages' \
diff --git a/solr/bin/solr.cmd b/solr/bin/solr.cmd
index d6ff9e62492..7167b1e3e9c 100755
--- a/solr/bin/solr.cmd
+++ b/solr/bin/solr.cmd
@@ -996,8 +996,7 @@ set SCRIPT_SOLR_OPTS=%SOLR_JAVA_STACK_SIZE% %SCRIPT_SOLR_OPTS%
 IF "%SOLR_TIMEZONE%"=="" set SOLR_TIMEZONE=UTC
 
 IF "%GC_TUNE%"=="" (
-  set GC_TUNE=-XX:+UseG1GC ^
-    -XX:+PerfDisableSharedMem ^
+  set GC_TUNE=-XX:+PerfDisableSharedMem ^
     -XX:+ParallelRefProcEnabled ^
     -XX:MaxGCPauseMillis=250 ^
     -XX:+UseLargePages ^
@@ -1009,12 +1008,7 @@ REM Add vector optimizations module
 set SCRIPT_SOLR_OPTS=%SCRIPT_SOLR_OPTS% --add-modules jdk.incubator.vector
 
 IF "%GC_LOG_OPTS%"=="" (
-  set GC_LOG_OPTS="-Xlog:gc*"
-)
-if "%JAVA_VENDOR%" == "OpenJ9" (
-  set GC_LOG_OPTS=!GC_LOG_OPTS! "-Xverbosegclog:!SOLR_LOGS_DIR!\solr_gc.log" -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=9 -XX:GCLogFileSize=20M
-) else (
-  set GC_LOG_OPTS=!GC_LOG_OPTS! "-Xloggc:!SOLR_LOGS_DIR!\solr_gc.log" -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=9 -XX:GCLogFileSize=20M
+  set GC_LOG_OPTS="-Xlog:gc*:file=!SOLR_LOGS_DIR!\solr_gc.log:time,level,tags:filecount=9,filesize=20M"
 )
 
 IF "%verbose%"=="1" (
diff --git a/solr/bin/solr.in.cmd b/solr/bin/solr.in.cmd
index 9c2d9822eb2..0e48ca4834d 100755
--- a/solr/bin/solr.in.cmd
+++ b/solr/bin/solr.in.cmd
@@ -39,9 +39,8 @@ REM Increase Java Min/Max Heap as needed to support your indexing / query needs
 REM set SOLR_JAVA_MEM=-Xms512m -Xmx512m
 
 REM Configure verbose GC logging:
-REM For Java 8: if this is set, additional params will be added to specify the log file & rotation
-REM For Java 9 or higher: GC_LOG_OPTS is currently not supported unless you are using OpenJ9. Otherwise if you set it, the startup script will exit with failure.
-REM set GC_LOG_OPTS=-verbose:gc -XX:+PrintHeapAtGC -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime
+REM Settings this value overrides the default configuration.
+REM set GC_LOG_OPTS=-Xlog:gc*:time,level,tags,heap,tenuring,stop:filecount=9,filesize=20M
 
 REM Various GC settings have shown to work well for a number of common Solr workloads.
 REM See solr.cmd GC_TUNE for the default list.
diff --git a/solr/bin/solr.in.sh b/solr/bin/solr.in.sh
index 9d83a48c1c2..1834f29668c 100644
--- a/solr/bin/solr.in.sh
+++ b/solr/bin/solr.in.sh
@@ -39,15 +39,9 @@
 #SOLR_JAVA_MEM="-Xms512m -Xmx512m"
 
 # Enable verbose GC logging...
-#  * If this is unset, various default options will be selected depending on which JVM version is in use
-#  * For Java 8: if this is set, additional params will be added to specify the log file & rotation
-#  * For Java 9 or higher: each included opt param that starts with '-Xlog:gc', but does not include an
-#    output specifier, will have a 'file' output specifier (as well as formatting & rollover options)
-#    appended, using the effective value of the SOLR_LOGS_DIR.
+# If this is unset, various default options will be selected depending on which JVM version is in use
 #
-#GC_LOG_OPTS='-Xlog:gc*'  # (Java 9+)
-#GC_LOG_OPTS="-verbose:gc -XX:+PrintHeapAtGC -XX:+PrintGCDetails \
-#  -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime"
+#GC_LOG_OPTS='-Xlog:gc*:time,level,tags,heap,tenuring,stop:filecount=9,filesize=20M'
 
 # These GC settings have shown to work well for a number of common Solr workloads
 #GC_TUNE=" \
diff --git a/solr/cross-dc-manager/bin/cross-dc-manager b/solr/cross-dc-manager/bin/cross-dc-manager
index 82eea73b554..1dc4969af8d 100755
--- a/solr/cross-dc-manager/bin/cross-dc-manager
+++ b/solr/cross-dc-manager/bin/cross-dc-manager
@@ -84,13 +84,6 @@ else
   JAVA_MEM_OPTS="-Xms$JAVA_HEAP -Xmx$JAVA_HEAP"
 fi
 
-# define default GC_TUNE
-if [ -z ${GC_TUNE+x} ]; then
-    GC_TUNE='-XX:+UseG1GC'
-else
-    GC_TUNE="$GC_TUNE"
-fi
-
 # For Cygwin, switch paths to Windows format before running java
 if $cygwin; then
   [ -n "$CLASSPATH" ] && CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
diff --git a/solr/cross-dc-manager/bin/cross-dc-manager.cmd b/solr/cross-dc-manager/bin/cross-dc-manager.cmd
index 5be7731d133..3506ef2a024 100644
--- a/solr/cross-dc-manager/bin/cross-dc-manager.cmd
+++ b/solr/cross-dc-manager/bin/cross-dc-manager.cmd
@@ -65,7 +65,6 @@ set BASEDIR=%~dp0..
 
 IF NOT "%JAVA_HEAP%"=="" set JAVA_MEM=-Xms%JAVA_HEAP% -Xmx%JAVA_HEAP%
 IF "%JAVA_MEM%"=="" set JAVA_MEM=-Xms512m -Xmx512m
-IF "%GC_TUNE%"=="" set GC_TUNE=-XX:+UseG1GC
 
 if "%JAVACMD%"=="" set JAVACMD=java
 
diff --git a/solr/prometheus-exporter/bin/solr-exporter b/solr/prometheus-exporter/bin/solr-exporter
index 452e597ab55..61144d20cf5 100755
--- a/solr/prometheus-exporter/bin/solr-exporter
+++ b/solr/prometheus-exporter/bin/solr-exporter
@@ -84,13 +84,6 @@ else
   JAVA_MEM_OPTS="-Xms$JAVA_HEAP -Xmx$JAVA_HEAP"
 fi
 
-# define default GC_TUNE
-if [ -z ${GC_TUNE+x} ]; then
-    GC_TUNE='-XX:+UseG1GC'
-else
-    GC_TUNE="$GC_TUNE"
-fi
-
 # For Cygwin, switch paths to Windows format before running java
 if $cygwin; then
   [ -n "$CLASSPATH" ] && CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
diff --git a/solr/prometheus-exporter/bin/solr-exporter.cmd b/solr/prometheus-exporter/bin/solr-exporter.cmd
index 7e9dd2a91f2..5216403d019 100644
--- a/solr/prometheus-exporter/bin/solr-exporter.cmd
+++ b/solr/prometheus-exporter/bin/solr-exporter.cmd
@@ -65,7 +65,6 @@ set BASEDIR=%~dp0..
 
 IF NOT "%JAVA_HEAP%"=="" set JAVA_MEM=-Xms%JAVA_HEAP% -Xmx%JAVA_HEAP%
 IF "%JAVA_MEM%"=="" set JAVA_MEM=-Xms512m -Xmx512m
-IF "%GC_TUNE%"=="" set GC_TUNE=-XX:+UseG1GC
 
 if "%JAVACMD%"=="" set JAVACMD=java
 
diff --git a/solr/solr-ref-guide/modules/configuration-guide/pages/system-info-handler.adoc b/solr/solr-ref-guide/modules/configuration-guide/pages/system-info-handler.adoc
index afd8680858d..745cb296741 100644
--- a/solr/solr-ref-guide/modules/configuration-guide/pages/system-info-handler.adoc
+++ b/solr/solr-ref-guide/modules/configuration-guide/pages/system-info-handler.adoc
@@ -173,7 +173,6 @@ curl http://localhost:8983/solr/admin/info/system
       "classpath":"start.jar",
       "commandLineArgs":["-Xms512m",
         "-Xmx512m",
-        "-XX:+UseG1GC",
         "-XX:+PerfDisableSharedMem",
         "-XX:+ParallelRefProcEnabled",
         "-XX:MaxGCPauseMillis=250",
@@ -284,7 +283,6 @@ curl http://localhost:8983/solr/gettingstarted/admin/system
       "classpath":"start.jar",
       "commandLineArgs":["-Xms512m",
         "-Xmx512m",
-        "-XX:+UseG1GC",
         "-XX:+PerfDisableSharedMem",
         "-XX:+ParallelRefProcEnabled",
         "-XX:MaxGCPauseMillis=250",
diff --git a/solr/solr-ref-guide/modules/deployment-guide/pages/monitoring-with-prometheus-and-grafana.adoc b/solr/solr-ref-guide/modules/deployment-guide/pages/monitoring-with-prometheus-and-grafana.adoc
index 898be24b339..13d029eb8b5 100644
--- a/solr/solr-ref-guide/modules/deployment-guide/pages/monitoring-with-prometheus-and-grafana.adoc
+++ b/solr/solr-ref-guide/modules/deployment-guide/pages/monitoring-with-prometheus-and-grafana.adoc
@@ -228,7 +228,7 @@ This is ignored if `JAVA_HEAP` is provided.
 +
 [%autowidth,frame=none]
 |===
-|Optional |Default: `-XX:+UseG1GC`
+|Optional |Default: none
 |===
 +
 Custom Java garbage collection settings.
diff --git a/solr/solr-ref-guide/modules/deployment-guide/pages/taking-solr-to-production.adoc b/solr/solr-ref-guide/modules/deployment-guide/pages/taking-solr-to-production.adoc
index 4adb5fd6b57..b006fcd5b0e 100644
--- a/solr/solr-ref-guide/modules/deployment-guide/pages/taking-solr-to-production.adoc
+++ b/solr/solr-ref-guide/modules/deployment-guide/pages/taking-solr-to-production.adoc
@@ -193,7 +193,7 @@ The status command should give some basic information about the running Solr nod
     Tasks: 41 (limit: 25056)
    Memory: 517.1M
    CGroup: /system.slice/solr.service
-           └─3708 java -server -Xms256M -Xmx512M -XX:+UseG1GC -XX:+PerfDisableSharedMem -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=250 -XX:+UseLargePages -XX:+AlwaysPreTouch -Xlog:gc*:file=/var/solr/logs/solr_gc.log:time,...
+           └─3708 java -server -Xms256M -Xmx512M -XX:+PerfDisableSharedMem -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=250 -XX:+UseLargePages -XX:+AlwaysPreTouch -Xlog:gc*:file=/var/solr/logs/solr_gc.log:time,...
 Apr 16 20:41:47 localhost.localdomain systemd[1]: Starting Apache Solr...
 Apr 16 20:42:01 localhost.localdomain solr[3661]: [326B blob data]
 Apr 16 20:42:01 localhost.localdomain solr[3661]: Started Solr server on port 8983 (pid=3708). Happy searching!

From e46d13e296d831a9731c04a04d9006e80d02875a Mon Sep 17 00:00:00 2001
From: Christos Malliaridis <c.malliaridis@gmail.com>
Date: Sun, 1 Dec 2024 04:23:23 +0100
Subject: [PATCH 2/3] Revert removal of default GC configuration

---
 solr/benchmark/jmh.sh                                      | 2 +-
 solr/bin/solr                                              | 3 ++-
 solr/bin/solr.cmd                                          | 3 ++-
 solr/cross-dc-manager/bin/cross-dc-manager                 | 7 +++++++
 solr/cross-dc-manager/bin/cross-dc-manager.cmd             | 1 +
 solr/prometheus-exporter/bin/solr-exporter                 | 7 +++++++
 solr/prometheus-exporter/bin/solr-exporter.cmd             | 1 +
 .../configuration-guide/pages/system-info-handler.adoc     | 2 ++
 .../pages/monitoring-with-prometheus-and-grafana.adoc      | 2 +-
 .../deployment-guide/pages/taking-solr-to-production.adoc  | 2 +-
 10 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/solr/benchmark/jmh.sh b/solr/benchmark/jmh.sh
index 2027fd712a4..18f9875da19 100755
--- a/solr/benchmark/jmh.sh
+++ b/solr/benchmark/jmh.sh
@@ -52,7 +52,7 @@ echo "running JMH with args: $@"
 #                                                            MRM: I've also seen 15 claimed as a sweet spot.
 
 jvmArgs="-jvmArgs -Djmh.shutdownTimeout=5 -jvmArgs -Djmh.shutdownTimeout.step=3 -jvmArgs -Djava.security.egd=file:/dev/./urandom -jvmArgs -XX:+UnlockDiagnosticVMOptions -jvmArgs -XX:+DebugNonSafepoints -jvmArgs --add-opens=java.base/java.lang.reflect=ALL-UNNAMED"
-gcArgs="-jvmArgs -XX:+ParallelRefProcEnabled"
+gcArgs="-jvmArgs -XX:+UseG1GC -jvmArgs -XX:+ParallelRefProcEnabled"
 
 # -jvmArgs -Dlog4j2.debug 
 loggingArgs="-jvmArgs -Dlog4jConfigurationFile=./log4j2-bench.xml -jvmArgs -Dlog4j2.is.webapp=false -jvmArgs -Dlog4j2.garbagefreeThreadContextMap=true -jvmArgs -Dlog4j2.enableDirectEncoders=true -jvmArgs -Dlog4j2.enable.threadlocals=true"
diff --git a/solr/bin/solr b/solr/bin/solr
index f4b7e2c7060..38d7ed10d82 100755
--- a/solr/bin/solr
+++ b/solr/bin/solr
@@ -1187,7 +1187,8 @@ function start_solr() {
 
   # define default GC_TUNE
   if [ -z "${GC_TUNE}" ]; then
-      GC_TUNE_ARR=('-XX:+PerfDisableSharedMem' \
+      GC_TUNE_ARR=('-XX:+UseG1GC' \
+        '-XX:+PerfDisableSharedMem' \
         '-XX:+ParallelRefProcEnabled' \
         '-XX:MaxGCPauseMillis=250' \
         '-XX:+UseLargePages' \
diff --git a/solr/bin/solr.cmd b/solr/bin/solr.cmd
index 0df856c2ac0..baa3ba47957 100755
--- a/solr/bin/solr.cmd
+++ b/solr/bin/solr.cmd
@@ -973,7 +973,8 @@ set SCRIPT_SOLR_OPTS=%SOLR_JAVA_STACK_SIZE% %SCRIPT_SOLR_OPTS%
 IF "%SOLR_TIMEZONE%"=="" set SOLR_TIMEZONE=UTC
 
 IF "%GC_TUNE%"=="" (
-  set GC_TUNE=-XX:+PerfDisableSharedMem ^
+  set GC_TUNE=-XX:+UseG1GC ^
+    -XX:+PerfDisableSharedMem ^
     -XX:+ParallelRefProcEnabled ^
     -XX:MaxGCPauseMillis=250 ^
     -XX:+UseLargePages ^
diff --git a/solr/cross-dc-manager/bin/cross-dc-manager b/solr/cross-dc-manager/bin/cross-dc-manager
index 1dc4969af8d..82eea73b554 100755
--- a/solr/cross-dc-manager/bin/cross-dc-manager
+++ b/solr/cross-dc-manager/bin/cross-dc-manager
@@ -84,6 +84,13 @@ else
   JAVA_MEM_OPTS="-Xms$JAVA_HEAP -Xmx$JAVA_HEAP"
 fi
 
+# define default GC_TUNE
+if [ -z ${GC_TUNE+x} ]; then
+    GC_TUNE='-XX:+UseG1GC'
+else
+    GC_TUNE="$GC_TUNE"
+fi
+
 # For Cygwin, switch paths to Windows format before running java
 if $cygwin; then
   [ -n "$CLASSPATH" ] && CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
diff --git a/solr/cross-dc-manager/bin/cross-dc-manager.cmd b/solr/cross-dc-manager/bin/cross-dc-manager.cmd
index 3506ef2a024..5be7731d133 100644
--- a/solr/cross-dc-manager/bin/cross-dc-manager.cmd
+++ b/solr/cross-dc-manager/bin/cross-dc-manager.cmd
@@ -65,6 +65,7 @@ set BASEDIR=%~dp0..
 
 IF NOT "%JAVA_HEAP%"=="" set JAVA_MEM=-Xms%JAVA_HEAP% -Xmx%JAVA_HEAP%
 IF "%JAVA_MEM%"=="" set JAVA_MEM=-Xms512m -Xmx512m
+IF "%GC_TUNE%"=="" set GC_TUNE=-XX:+UseG1GC
 
 if "%JAVACMD%"=="" set JAVACMD=java
 
diff --git a/solr/prometheus-exporter/bin/solr-exporter b/solr/prometheus-exporter/bin/solr-exporter
index 49b03c99492..20377c4b171 100755
--- a/solr/prometheus-exporter/bin/solr-exporter
+++ b/solr/prometheus-exporter/bin/solr-exporter
@@ -84,6 +84,13 @@ else
   JAVA_MEM_OPTS="-Xms$JAVA_HEAP -Xmx$JAVA_HEAP"
 fi
 
+# define default GC_TUNE
+if [ -z ${GC_TUNE+x} ]; then
+    GC_TUNE='-XX:+UseG1GC'
+else
+    GC_TUNE="$GC_TUNE"
+fi
+
 # For Cygwin, switch paths to Windows format before running java
 if $cygwin; then
   [ -n "$CLASSPATH" ] && CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
diff --git a/solr/prometheus-exporter/bin/solr-exporter.cmd b/solr/prometheus-exporter/bin/solr-exporter.cmd
index 26c20873882..c55133db616 100644
--- a/solr/prometheus-exporter/bin/solr-exporter.cmd
+++ b/solr/prometheus-exporter/bin/solr-exporter.cmd
@@ -65,6 +65,7 @@ set BASEDIR=%~dp0..
 
 IF NOT "%JAVA_HEAP%"=="" set JAVA_MEM=-Xms%JAVA_HEAP% -Xmx%JAVA_HEAP%
 IF "%JAVA_MEM%"=="" set JAVA_MEM=-Xms512m -Xmx512m
+IF "%GC_TUNE%"=="" set GC_TUNE=-XX:+UseG1GC
 
 if "%JAVACMD%"=="" set JAVACMD=java
 
diff --git a/solr/solr-ref-guide/modules/configuration-guide/pages/system-info-handler.adoc b/solr/solr-ref-guide/modules/configuration-guide/pages/system-info-handler.adoc
index 745cb296741..afd8680858d 100644
--- a/solr/solr-ref-guide/modules/configuration-guide/pages/system-info-handler.adoc
+++ b/solr/solr-ref-guide/modules/configuration-guide/pages/system-info-handler.adoc
@@ -173,6 +173,7 @@ curl http://localhost:8983/solr/admin/info/system
       "classpath":"start.jar",
       "commandLineArgs":["-Xms512m",
         "-Xmx512m",
+        "-XX:+UseG1GC",
         "-XX:+PerfDisableSharedMem",
         "-XX:+ParallelRefProcEnabled",
         "-XX:MaxGCPauseMillis=250",
@@ -283,6 +284,7 @@ curl http://localhost:8983/solr/gettingstarted/admin/system
       "classpath":"start.jar",
       "commandLineArgs":["-Xms512m",
         "-Xmx512m",
+        "-XX:+UseG1GC",
         "-XX:+PerfDisableSharedMem",
         "-XX:+ParallelRefProcEnabled",
         "-XX:MaxGCPauseMillis=250",
diff --git a/solr/solr-ref-guide/modules/deployment-guide/pages/monitoring-with-prometheus-and-grafana.adoc b/solr/solr-ref-guide/modules/deployment-guide/pages/monitoring-with-prometheus-and-grafana.adoc
index 8be95297d75..006888ede88 100644
--- a/solr/solr-ref-guide/modules/deployment-guide/pages/monitoring-with-prometheus-and-grafana.adoc
+++ b/solr/solr-ref-guide/modules/deployment-guide/pages/monitoring-with-prometheus-and-grafana.adoc
@@ -228,7 +228,7 @@ This is ignored if `JAVA_HEAP` is provided.
 +
 [%autowidth,frame=none]
 |===
-|Optional |Default: none
+|Optional |Default: `-XX:+UseG1GC`
 |===
 +
 Custom Java garbage collection settings.
diff --git a/solr/solr-ref-guide/modules/deployment-guide/pages/taking-solr-to-production.adoc b/solr/solr-ref-guide/modules/deployment-guide/pages/taking-solr-to-production.adoc
index b006fcd5b0e..4adb5fd6b57 100644
--- a/solr/solr-ref-guide/modules/deployment-guide/pages/taking-solr-to-production.adoc
+++ b/solr/solr-ref-guide/modules/deployment-guide/pages/taking-solr-to-production.adoc
@@ -193,7 +193,7 @@ The status command should give some basic information about the running Solr nod
     Tasks: 41 (limit: 25056)
    Memory: 517.1M
    CGroup: /system.slice/solr.service
-           └─3708 java -server -Xms256M -Xmx512M -XX:+PerfDisableSharedMem -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=250 -XX:+UseLargePages -XX:+AlwaysPreTouch -Xlog:gc*:file=/var/solr/logs/solr_gc.log:time,...
+           └─3708 java -server -Xms256M -Xmx512M -XX:+UseG1GC -XX:+PerfDisableSharedMem -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=250 -XX:+UseLargePages -XX:+AlwaysPreTouch -Xlog:gc*:file=/var/solr/logs/solr_gc.log:time,...
 Apr 16 20:41:47 localhost.localdomain systemd[1]: Starting Apache Solr...
 Apr 16 20:42:01 localhost.localdomain solr[3661]: [326B blob data]
 Apr 16 20:42:01 localhost.localdomain solr[3661]: Started Solr server on port 8983 (pid=3708). Happy searching!

From 3e719866b06512270fcd249287c4defe0fd48992 Mon Sep 17 00:00:00 2001
From: Christos Malliaridis <c.malliaridis@gmail.com>
Date: Mon, 23 Dec 2024 19:29:42 +0100
Subject: [PATCH 3/3] Fix wrong path separator in bin/solr

---
 solr/bin/solr | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/solr/bin/solr b/solr/bin/solr
index 73b5b516338..6df002eaf22 100755
--- a/solr/bin/solr
+++ b/solr/bin/solr
@@ -1053,7 +1053,7 @@ fi
 
 # Establish default GC logging opts if no env var set
 if [ -z "${GC_LOG_OPTS}" ]; then
-  GC_LOG_OPTS=("-Xlog:gc*:file=$SOLR_LOGS_DIR\solr_gc.log:time,level,tags:filecount=9,filesize=20M")
+  GC_LOG_OPTS=("-Xlog:gc*:file=$SOLR_LOGS_DIR/solr_gc.log:time,level,tags:filecount=9,filesize=20M")
 fi
 
 if [ "${SOLR_MODE:-}" == 'solrcloud' ]; then