Allow configuration of the GC log file via an environment variable

Enabling GC logging works now by setting the environment variable ES_GC_LOG_FILE
to the full path to the GC log file. Missing directories will be created as needed.

The ES_USE_GC_LOGGING environment variable is no longer used.

Closes #8471
Closes #8479

bin/elasticsearch

@@ -96,7 +96,7 @@ if [ "x$ES_INCLUDE" = "x" ]; then
                    /usr/local/share/elasticsearch/elasticsearch.in.sh \
                    /opt/elasticsearch/elasticsearch.in.sh \
                    ~/.elasticsearch.in.sh \
-                   $ES_HOME/bin/elasticsearch.in.sh \
+                   "$ES_HOME/bin/elasticsearch.in.sh" \
                    "`dirname "$0"`"/elasticsearch.in.sh; do
         if [ -r "$include" ]; then
             . "$include"
@@ -151,13 +151,13 @@ launch_service()
     # The es-foreground option will tell Elasticsearch not to close stdout/stderr, but it's up to us not to daemonize.
     if [ "x$daemonized" = "x" ]; then
         es_parms="$es_parms -Des.foreground=yes"
-        exec "$JAVA" $JAVA_OPTS $ES_JAVA_OPTS $es_parms -Des.path.home="$ES_HOME" -cp "$ES_CLASSPATH" $props \
+        eval exec "$JAVA" $JAVA_OPTS $ES_JAVA_OPTS $es_parms "\"-Des.path.home=$ES_HOME\"" -cp "\"$ES_CLASSPATH\"" $props \
                 org.elasticsearch.bootstrap.Elasticsearch
         # exec without running it in the background, makes it replace this shell, we'll never get here...
         # no need to return something
     else
         # Startup Elasticsearch, background it, and write the pid.
-        exec "$JAVA" $JAVA_OPTS $ES_JAVA_OPTS $es_parms -Des.path.home="$ES_HOME" -cp "$ES_CLASSPATH" $props \
+        eval exec "$JAVA" $JAVA_OPTS $ES_JAVA_OPTS $es_parms "\"-Des.path.home=$ES_HOME\"" -cp "\"$ES_CLASSPATH\"" $props \
                     org.elasticsearch.bootstrap.Elasticsearch <&- &
         return $?
     fi
@@ -207,7 +207,7 @@ eval set -- "$args"
 while true; do
     case $1 in
         -v)
-            "$JAVA" $JAVA_OPTS $ES_JAVA_OPTS $es_parms -Des.path.home="$ES_HOME" -cp "$ES_CLASSPATH" $props \
+            eval "$JAVA" $JAVA_OPTS $ES_JAVA_OPTS $es_parms "\"-Des.path.home=$ES_HOME\"" -cp "\"$ES_CLASSPATH\"" $props \
                     org.elasticsearch.Version
             exit 0
         ;;

bin/elasticsearch.in.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-ES_CLASSPATH=$ES_CLASSPATH:$ES_HOME/lib/${project.build.finalName}.jar:$ES_HOME/lib/*:$ES_HOME/lib/sigar/*
+ES_CLASSPATH="$ES_CLASSPATH:$ES_HOME/lib/${project.build.finalName}.jar:$ES_HOME/lib/*:$ES_HOME/lib/sigar/*"
 
 if [ "x$ES_MIN_MEM" = "x" ]; then
     ES_MIN_MEM=256m
@@ -45,13 +45,16 @@ JAVA_OPTS="$JAVA_OPTS -XX:CMSInitiatingOccupancyFraction=75"
 JAVA_OPTS="$JAVA_OPTS -XX:+UseCMSInitiatingOccupancyOnly"
 
 # GC logging options
-if [ "x$ES_USE_GC_LOGGING" != "x" ]; then
+if [ -n "$ES_GC_LOG_FILE" ]; then
   JAVA_OPTS="$JAVA_OPTS -XX:+PrintGCDetails"
   JAVA_OPTS="$JAVA_OPTS -XX:+PrintGCTimeStamps"
   JAVA_OPTS="$JAVA_OPTS -XX:+PrintClassHistogram"
   JAVA_OPTS="$JAVA_OPTS -XX:+PrintTenuringDistribution"
   JAVA_OPTS="$JAVA_OPTS -XX:+PrintGCApplicationStoppedTime"
-  JAVA_OPTS="$JAVA_OPTS -Xloggc:/var/log/elasticsearch/gc.log"
+  JAVA_OPTS="$JAVA_OPTS \"-Xloggc:$ES_GC_LOG_FILE\""
+
+  # Ensure that the directory for the log file exists: the JVM will not create it.
+  mkdir -p "`dirname \"$ES_GC_LOG_FILE\"`"
 fi
 
 # Causes the JVM to dump its heap on OutOfMemory.

docs/reference/setup/as-a-service.asciidoc

@@ -26,6 +26,7 @@ Each package features a configuration file, which allows you to set the followin
 `CONF_FILE`::             Path to configuration file, defaults to `/etc/elasticsearch/elasticsearch.yml`
 `ES_JAVA_OPTS`::          Any additional java options you may want to apply. This may be useful, if you need to set the `node.name` property, but do not want to change the `elasticsearch.yml` configuration file, because it is distributed via a provisioning system like puppet or chef. Example: `ES_JAVA_OPTS="-Des.node.name=search-01"`
 `RESTART_ON_UPGRADE`::    Configure restart on package upgrade, defaults to `false`. This means you will have to restart your elasticsearch instance after installing a package manually. The reason for this is to ensure, that upgrades in a cluster do not result in a continuous shard reallocation resulting in high network traffic and reducing the response times of your cluster.
+`ES_GC_LOG_FILE` ::       The absolute log file path for creating a garbage collection logfile, which is done by the JVM. Note that this logfile can grow pretty quick and thus is disabled by default.
 
 [float]
 ==== Debian/Ubuntu

src/deb/default/elasticsearch

@@ -42,3 +42,6 @@
 
 # Configure restart on package upgrade (true, every other setting will lead to not restarting)
 #RESTART_ON_UPGRADE=true
+
+# Path to the GC log file
+#ES_GC_LOG_FILE=/var/log/elasticsearch/gc.log

src/deb/init.d/elasticsearch

@@ -94,6 +94,9 @@ CONF_FILE=$CONF_DIR/elasticsearch.yml
 # Maximum number of VMA (Virtual Memory Areas) a process can own
 MAX_MAP_COUNT=262144
 
+# Path to the GC log file
+#ES_GC_LOG_FILE=/var/log/elasticsearch/gc.log
+
 # End of variables that can be overwritten in $DEFAULT
 
 # overwrite settings from default file
@@ -110,6 +113,7 @@ export ES_HEAP_SIZE
 export ES_HEAP_NEWSIZE
 export ES_DIRECT_SIZE
 export ES_JAVA_OPTS
+export ES_GC_LOG_FILE
 
 # Check DAEMON exists
 test -x $DAEMON || exit 0

src/rpm/init.d/elasticsearch

@@ -41,6 +41,7 @@ export ES_HEAP_SIZE
 export ES_HEAP_NEWSIZE
 export ES_DIRECT_SIZE
 export ES_JAVA_OPTS
+export ES_GC_LOG_FILE
 export JAVA_HOME
 
 lockfile=/var/lock/subsys/$prog
@@ -84,6 +85,8 @@ start() {
         mkdir -p "$WORK_DIR"
         chown "$ES_USER":"$ES_GROUP" "$WORK_DIR"
     fi
+    export ES_GC_LOG_FILE
+
     echo -n $"Starting $prog: "
     # if not running, start it up here, usually something like "daemon $exec"
     daemon --user $ES_USER --pidfile $pidfile $exec -p $pidfile -d -Des.default.path.home=$ES_HOME -Des.default.path.logs=$LOG_DIR -Des.default.path.data=$DATA_DIR -Des.default.path.work=$WORK_DIR -Des.default.path.conf=$CONF_DIR

src/rpm/sysconfig/elasticsearch

@@ -44,3 +44,6 @@ ES_USER=elasticsearch
 
 # Configure restart on package upgrade (true, every other setting will lead to not restarting)
 #RESTART_ON_UPGRADE=true
+
+# Path to the GC log file
+#ES_GC_LOG_FILE=/var/log/elasticsearch/gc.log