tomcat设置详解：详解Tomcat调优和Tomcat监控
tomcat设置详解：详解Tomcat调优和Tomcat监控他们在文件中的注释如下：在Tomcat的catalina.sh文件中的启停server脚本中都应用到了两个变量： CATALINA_OPTS和JAVA_OPTS。用于保存Tomcat运行所需的各种参数。CATALINA_OPTS catalina运行时的参数 heap size 、GC logging、JMX ports etcJAVA_OPTS java运行时的参数 heap size 、GC logging、JMX ports etc两者的区别：
tomcat调优vi catalina.sh # ----------------------------------------------------------------------------- # Control Script for the CATALINA Server # # Environment Variable Prerequisites # # Do not set the variables in this script. Instead put them into a script # setenv.sh in CATALINA_base/bin to keep your customizations separate. # # CATALINA_HOME May point at your Catalina "build" directory. # # CATALINA_BASE (Optional) Base directory for resolving dynamic portions # of a Catalina installation. If not present resolves to # the same directory that CATALINA_HOME points to. # # CATALINA_OUT (Optional) Full path to a file where stdout and stderr # will be redirected. # Default is $CATALINA_BASE/logs/catalina.out # # CATALINA_OPTS (Optional) Java runtime options used when the "start" # "run" or "debug" command is executed. # Include here and not in JAVA_OPTS all options that should # only be used by Tomcat itself not by the stop process # the version command etc. # Examples are heap size GC logging JMX ports etc. # # CATALINA_TMPDIR (Optional) Directory path location of temporary directory # the JVM should use (java.io.tmpdir). Defaults to # $CATALINA_BASE/temp. # # JAVA_HOME Must point at your Java Development Kit installation. # Required to run the with the "debug" argument. # # JRE_HOME Must point at your Java Runtime installation. # Defaults to JAVA_HOME if empty. If JRE_HOME and JAVA_HOME # are both set JRE_HOME is used. # # JAVA_OPTS (Optional) Java runtime options used when any command # is executed. # Include here and not in CATALINA_OPTS all options that # should be used by Tomcat and also by the stop process # the version command etc. # Most options should go into CATALINA_OPTS. # # JAVA_ENDORSED_DIRS (Optional) Lists of of colon separated directories # containing some jars in order to allow replacement of APIs # created outside of the JCP (i.e. DOM and SAX from W3C). # It can also be used to update the XML parser implementation. # Note that Java 9 no longer supports this feature. # Defaults to $CATALINA_HOME/endorsed. # # JPDA_TRANSPORT (Optional) JPDA transport used when the "jpda start" # command is executed. The default is "dt_socket". #
catalina这个脚本会读取很多参数：
CATALINA_HOME tomcat的安装目录
CATALINA_BASE tomcat的工作目录
如果我们想要运行Tomcat的 多个实例，但是不想安装多个Tomcat软件副本。那么我们可以配置多个工作目录，每个运行实例独占一个工作目录，但是共享同一个安装目录。
CATALINA_OPTS catalina运行时的参数 heap size 、GC logging、JMX ports etc
JAVA_OPTS java运行时的参数 heap size 、GC logging、JMX ports etc
两者的区别：
在Tomcat的catalina.sh文件中的启停server脚本中都应用到了两个变量： CATALINA_OPTS和JAVA_OPTS。用于保存Tomcat运行所需的各种参数。
他们在文件中的注释如下：
（可选）Java 执行"start" "stop"或"run"命令时用到的运行时参数； [JAVA_OPTS]
（可选）Java 执行"start"或"run"命令时用到的运行时参数； [CATALINA_OPTS]
那么，为什么有两个不同的变量？他们有什么区别？
首先，定义在这两个变量中的参数都会被传递到启动Tomcat的命令：“start"和"run”，只有定义在JAVA_OPTS中的参数会被传递到"stop"命令。
所以将参数定义到哪个变量中并不影响Tomcat的启动和运行，而只影响到了Tomcat的运行结束。
第二种区别更加微妙。其他应用程序也可以使用JAVA_OPTS，但Tomcat只会用到CATALINA_OPTS。所以如果你只使用了Tomcat，在设置环境变量时，你最好使用CATALINA_OPTS，而如果你同时也用到了其他java应用程序，如JBoss，在设置环境变量时你应该使用JAVA_OPTS。
if $cygwin; then [ -n "$JAVA_HOME" ] && JAVA_HOME=`cygpath --unix "$JAVA_HOME"` [ -n "$JRE_HOME" ] && JRE_HOME=`cygpath --unix "$JRE_HOME"` [ -n "$CATALINA_HOME" ] && CATALINA_HOME=`cygpath --unix "$CATALINA_HOME"` [ -n "$CATALINA_BASE" ] && CATALINA_BASE=`cygpath --unix "$CATALINA_BASE"` [ -n "$CLASSPATH" ] && CLASSPATH=`cygpath --path --unix "$CLASSPATH"` fi
发现脚本是可以自动获取这些值的
exec "$_RUNJDB" "$LOGGING_CONFIG" $LOGGING_MANAGER $JAVA_OPTS $CATALINA_OPTS \ -D$ENDORSED_PROP="$JAVA_ENDORSED_DIRS" \ -classpath "$CLASSPATH" \ -sourcepath "$CATALINA_HOME"/../../java \ -Djava.security.manager \ -Djava.security.policy=="$CATALINA_BASE"/conf/catalina.policy \ -Dcatalina.base="$CATALINA_BASE" \ -Dcatalina.home="$CATALINA_HOME" \ -Djava.io.tmpdir="$CATALINA_TMPDIR" \ org.apache.catalina.startup.Bootstrap "$@" start
根据这些参数$JAVA_OPTS $CATALINA_OPTS 来启动tomcat
所以只需要在前面添加：
例如：
//其他的参数也同理 export JAVA_OPTS="-Xms:100m -Xmx:2048m"
后面会自动读取
tomcat监控
jps xxxx Bootstrap //1s打印一次 jstat -gc xxxx 1s
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