Revert removal of default GC configuration

Author: malliaridis

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 -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"

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' \

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 ^

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"`

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
 

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"`

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
 

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",

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.

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!