SOLR-9534: You can now set Solr's log level through environment variable SOLR_LOG_LEVEL and -q and -v options to bin/solr

solr/CHANGES.txt

@@ -92,6 +92,9 @@ New Features
 
 * SOLR-8487: Adds CommitStream to support sending commits to a collection being updated. (Dennis Gove)
 
+* SOLR-9534: You can now set Solr's log level through environment variable SOLR_LOG_LEVEL
+  Also adds conveience arguments -q (quiet: WARN) and -v (verbose: DEBUG) to bin/solr (janhoy)
+
 Bug Fixes
 ----------------------
 

solr/bin/solr

@@ -258,7 +258,9 @@ function print_usage() {
     echo ""
     echo "  -noprompt     Don't prompt for input; accept all defaults when running examples that accept user input"
     echo ""
-    echo "  -V            Verbose messages from this script"
+    echo "  -v and -q     Verbose (-v) or quiet (-q) logging. Sets default log level to DEBUG or WARN instead of INFO"
+    echo ""
+    echo "  -V or -version Verbose messages from this script"
     echo ""
   elif [ "$CMD" == "stop" ]; then
     echo ""
@@ -1160,6 +1162,14 @@ if [ $# -gt 0 ]; then
             PASS_TO_RUN_EXAMPLE+=" --verbose"
             shift
         ;;
+        -v)
+            SOLR_LOG_LEVEL=DEBUG
+            shift
+        ;;
+        -q)
+            SOLR_LOG_LEVEL=WARN
+            shift
+        ;;
         -all)
             stop_all=true
             shift
@@ -1187,6 +1197,10 @@ if [ $# -gt 0 ]; then
   done
 fi
 
+if [[ $SOLR_LOG_LEVEL ]] ; then
+  SOLR_LOG_LEVEL_OPT="-Dsolr.log.level=$SOLR_LOG_LEVEL"
+fi
+
 if [ -z "$SOLR_SERVER_DIR" ]; then
   SOLR_SERVER_DIR="$DEFAULT_SERVER_DIR"
 fi
@@ -1518,6 +1532,11 @@ function launch_solr() {
       echo -e "    RMI_PORT        = $RMI_PORT"
       echo -e "    REMOTE_JMX_OPTS = ${REMOTE_JMX_OPTS[@]}"
     fi
+
+    if [ "$SOLR_LOG_LEVEL" != "" ]; then
+      echo -e "    SOLR_LOG_LEVEL  = $SOLR_LOG_LEVEL"
+    fi
+
     echo -e "\n"
   fi
     
@@ -1530,7 +1549,7 @@ function launch_solr() {
   fi
 
   SOLR_START_OPTS=('-server' "${JAVA_MEM_OPTS[@]}" "${GC_TUNE[@]}" "${GC_LOG_OPTS[@]}" \
-    "${REMOTE_JMX_OPTS[@]}" "${CLOUD_MODE_OPTS[@]}" \
+    "${REMOTE_JMX_OPTS[@]}" "${CLOUD_MODE_OPTS[@]}" $SOLR_LOG_LEVEL_OPT \
     "-Djetty.port=$SOLR_PORT" "-DSTOP.PORT=$stop_port" "-DSTOP.KEY=$STOP_KEY" \
     "${SOLR_HOST_ARG[@]}" "-Duser.timezone=$SOLR_TIMEZONE" \
     "-Djetty.home=$SOLR_SERVER_DIR" "-Dsolr.solr.home=$SOLR_HOME" "-Dsolr.install.dir=$SOLR_TIP" \

solr/bin/solr.cmd

@@ -222,6 +222,8 @@ goto done
 @echo.
 @echo   -noprompt     Don't prompt for input; accept all defaults when running examples that accept user input
 @echo.
+@echo   -v and -q     Verbose (-v) or quiet (-q) logging. Sets default log level to DEBUG or WARN instead of INFO
+@echo.
 @echo   -V            Verbose messages from this script
 @echo.
 goto done
@@ -439,6 +441,8 @@ IF "%1"=="-f" goto set_foreground_mode
 IF "%1"=="-foreground" goto set_foreground_mode
 IF "%1"=="-V" goto set_verbose
 IF "%1"=="-verbose" goto set_verbose
+IF "%1"=="-v" goto set_debug
+IF "%1"=="-q" goto set_warn
 IF "%1"=="-c" goto set_cloud_mode
 IF "%1"=="-cloud" goto set_cloud_mode
 IF "%1"=="-d" goto set_server_dir
@@ -481,6 +485,16 @@ set "PASS_TO_RUN_EXAMPLE=--verbose !PASS_TO_RUN_EXAMPLE!"
 SHIFT
 goto parse_args
 
+:set_debug
+set SOLR_LOG_LEVEL=DEBUG
+SHIFT
+goto parse_args
+
+:set_warn
+set SOLR_LOG_LEVEL=WARN
+SHIFT
+goto parse_args
+
 :set_cloud_mode
 set SOLR_MODE=solrcloud
 SHIFT
@@ -931,6 +945,10 @@ IF "%verbose%"=="1" (
     @echo     REMOTE_JMX_OPTS = %REMOTE_JMX_OPTS%
   )
 
+  IF NOT "%SOLR_LOG_LEVEL%"=="" (
+    @echo     SOLR_LOG_LEVEL  = !SOLR_LOG_LEVEL!
+  )
+
   @echo.
 )
 
@@ -945,6 +963,7 @@ IF NOT "%SOLR_SSL_OPTS%"=="" (
   set "SSL_PORT_PROP=-Dsolr.jetty.https.port=%SOLR_PORT%"
   set "START_OPTS=%START_OPTS% %SOLR_SSL_OPTS% !SSL_PORT_PROP!"
 )
+IF NOT "%SOLR_LOG_LEVEL%"=="" set "START_OPTS=%START_OPTS% -Dsolr.log.level=%SOLR_LOG_LEVEL%"
 
 IF NOT DEFINED LOG4J_CONFIG set "LOG4J_CONFIG=file:%SOLR_SERVER_DIR%\resources\log4j.properties"
 

solr/bin/solr.in.cmd

@@ -27,6 +27,10 @@ set SOLR_JAVA_MEM=-Xms512m -Xmx512m
 REM Enable verbose GC logging
 set GC_LOG_OPTS=-verbose:gc -XX:+PrintHeapAtGC -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime
 
+REM Changes the logging level. Valid values: ALL, TRACE, DEBUG, INFO, WARN, ERROR, FATAL, OFF. Default is INFO
+REM This is an alternative to changing the rootLogger in log4j.properties
+REM set SOLR_LOG_LEVEL=INFO
+
 REM These GC settings have shown to work well for a number of common Solr workloads
 set GC_TUNE=-XX:NewRatio=3 ^
  -XX:SurvivorRatio=4 ^

solr/bin/solr.in.sh

@@ -91,6 +91,10 @@ SOLR_OPTS="$SOLR_OPTS -Xss256k"
 # so you can point the script to use a different log4j.properties file
 #LOG4J_PROPS=/var/solr/log4j.properties
 
+# Changes the logging level. Valid values: ALL, TRACE, DEBUG, INFO, WARN, ERROR, FATAL, OFF. Default is INFO
+# This is an alternative to changing the rootLogger in log4j.properties
+#SOLR_LOG_LEVEL=INFO
+
 # Location where Solr should write logs to; should agree with the file appender
 # settings in server/resources/log4j.properties
 #SOLR_LOGS_DIR=

solr/core/src/java/org/apache/solr/servlet/SolrDispatchFilter.java

@@ -114,6 +114,8 @@ public class SolrDispatchFilter extends BaseSolrFilter {
 
   public static final String SOLR_LOG_MUTECONSOLE = "solr.log.muteconsole";
 
+  public static final String SOLR_LOG_LEVEL = "solr.log.level";
+
   @Override
   public void init(FilterConfig config) throws ServletException
   {
@@ -122,7 +124,10 @@ public class SolrDispatchFilter extends BaseSolrFilter {
     if (muteConsole != null && !Arrays.asList("false","0","off","no").contains(muteConsole.toLowerCase(Locale.ROOT))) {
       StartupLoggingUtils.muteConsole();
     }
-    log.info("SolrDispatchFilter.init(): {}", this.getClass().getClassLoader());
+    String logLevel = System.getProperty(SOLR_LOG_LEVEL);
+    if (logLevel != null) {
+      StartupLoggingUtils.changeLogLevel(logLevel);
+    }
 
     String exclude = config.getInitParameter("excludePatterns");
     if(exclude != null) {

solr/core/src/java/org/apache/solr/servlet/StartupLoggingUtils.java

@@ -22,6 +22,7 @@ import java.util.Enumeration;
 
 import org.apache.log4j.Appender;
 import org.apache.log4j.ConsoleAppender;
+import org.apache.log4j.Level;
 import org.apache.log4j.LogManager;
 import org.apache.solr.common.util.SuppressForbidden;
 import org.slf4j.Logger;
@@ -67,6 +68,27 @@ final class StartupLoggingUtils {
     }
   }
 
+  /**
+   * Dynamically change log4j log level through property solr.log.level
+   * @param logLevel String with level, should be one of the supported, e.g. TRACE, DEBUG, INFO, WARN, ERROR...
+   * @return true if ok or else false if something happened, e.g. log4j classes were not in classpath
+   */
+  @SuppressForbidden(reason = "Legitimate log4j access")
+  static boolean changeLogLevel(String logLevel) {
+    try {
+      if (!isLog4jActive()) {
+        logNotSupported("Could not mute logging to console.");
+        return false;
+      }
+      log.info("Log level override, property solr.log.level=" + logLevel);
+      LogManager.getRootLogger().setLevel(Level.toLevel(logLevel, Level.INFO));
+      return true;
+    } catch (Exception e) {
+      logNotSupported("Could not change log level.");
+      return false;
+    }
+  }
+
   private static boolean isLog4jActive() {
     try {
       // Make sure we have log4j LogManager in classpath

solr/server/resources/log4j.properties

@@ -1,4 +1,5 @@
-#  Logging level
+# Default Solr log4j config
+# rootLogger log level may be programmatically overridden by -Dsolr.log.level
 solr.log=logs
 log4j.rootLogger=INFO, file, CONSOLE
 
@@ -17,11 +18,12 @@ log4j.appender.file.File=${solr.log}/solr.log
 log4j.appender.file.layout=org.apache.log4j.EnhancedPatternLayout
 log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss.SSS} %-5p (%t) [%X{collection} %X{shard} %X{replica} %X{core}] %c{1.} %m%n
 
+# Adjust logging levels that should differ from root logger
 log4j.logger.org.apache.zookeeper=WARN
 log4j.logger.org.apache.hadoop=WARN
 log4j.logger.org.eclipse.jetty=WARN
-log4j.logger.org.eclipse.jetty.server=INFO
+log4j.logger.org.eclipse.jetty.server.Server=INFO
-log4j.logger.org.eclipse.jetty.server.handler=WARN
+log4j.logger.org.eclipse.jetty.server.ServerConnector=INFO
 
 # set to INFO to enable infostream log messages
 log4j.logger.org.apache.solr.update.LoggingInfoStream=OFF