shutdown.sh -force保证tomcat完全关闭
- tomcat的catalina.sh中说明了如果想要加什么参数，不要修改catalina.sh，在
CATALINA_BASE/bin创建一个setenv.sh，并设置CATALINA_OPTS。 -
JAVA_OPTS中的参数在关闭tomcat的时候也会参与，大部分的参数应该放到CATALINA_OPTS中。CATALINA_OPTS只在tomcat启动中参与。 -
CATALINA_PID中会存放tomcat启动后的pid。 - 使用shutdown.sh的时候添加-force参数，如果5s后tomcat还存活会使用kill命令杀掉，还可以通过-n制定等待秒数，kill的进程号需要
CATALINA_PID参数 - catalina.sh中和本文有关的内容如下
# 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_OPTS (Optional) Java runtime options used when the "start",
# "run" or "debug" command is executed.
# JAVA_OPTS (Optional) Java runtime options used when any command
# is executed.
# Most options should go into CATALINA_OPTS.
# CATALINA_PID (Optional) Path of the file which should contains the pid
# of the catalina startup java process, when start (fork) is
# used
echo " stop -force Stop Catalina, wait up to 5 seconds and then use kill -KILL if still running"
echo " stop n -force Stop Catalina, wait up to n seconds and then use kill -KILL if still running"
echo "Note: Waiting for the process to end and use of the -force option require that \$CATALINA_PID is defined"
- 创建如下内容的setenv.sh
#!/bin/sh
CATALINA_OPTS="-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=127.0.0.1:9000 -Djava.security.egd=file:/dev/urandom"
CATALINA_PID=$CATALINA_HOME/bin/tomcat.pid
解决tomcat启动超慢的问题
- tomcat启动慢的罪魁祸首是启动时实例化一个SecureRandom实例特别慢，catalina.out中日志如下：
Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took **[1,718,769] milliseconds.**
- 构造SecureRandom实例会使用系统的/dev/random生成随机数，但是/dev/random依赖系统中断，所以随机数更加随机但是产生的可能会很慢
- 所以我们使用/dev/urandom代替/dev/random就可以了，这两个随机数生成器的区别网上一堆，这里不贴了
- 有两种解决办法
- 在tomcat启动参数中指定Djava.security.egd=file:/dev/urandom(和上面)
- 修改
/usr/java/default/jre/lib/security/java.security中指定securerandom.source=file:/dev/urandom
