1、前言
首先要回答一个问题,为什么要用单机多实例?
在不宕机的情况下,webapps里面存在多个项目,可能由于其中一个项目过度使用内存或者其他不确定的因素使得tomcat挂了,那么同一tomcat下的项目也会一同挂了;而使用不同的tomcat,同一台服务器下,每个tomcat的进程是不一样的额,一个项目出现问题tomcat挂了,那么由于是在不同进程,其他项目不会影响的。
还有一个问题就是不同tomcat使用了不同端口,最后域名只有一个怎么分配?
其实这个使用nginx的反向代理,根据请求的前缀,代理到相应的tomcat项目服务端口对应的nginx server即可。
2、系统环境
系统:16.04.5 lts
jdk版本:openjdk 1.8
tomcat版本:apache-tomcat-9.0.13
3、环境搭建
3.1、下载tomcat
安装jdk:
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apt-get install openjdk- 8 -jdk
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访问官网:https://tomcat.apache.org/download-90.cgi
找到core,点击tar.gz带弹出下载连接复制下载地址。
然后使用命令下载tomcat
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wget http: //mirrors .hust.edu.cn /apache/tomcat/tomcat-9/v9 .0.13 /bin/apache-tomcat-9 .0.13. tar .gz
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解压tomcat:
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tar -xzvf apache-tomcat-9.0.13. tar .gz
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建一个程序目录:
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##创建一个程序目录
mkdir /data
##移动解压文件到data目录下
mv . /apache-tomcat-9 .0.13 /data/
cp /etc/profile /etc/profile .bak
echo "export catalina_home=/data/apache-tomcat-9.0.13" >> /etc/profile
echo "export path=\$path:\$catalina_home/bin" >> /etc/profile && source /etc/profile
##创建sh文件
touch tomcat-start.sh tomcat-stop.sh
##更改权限
chmod 760 /data/tomcat-start .sh /data/tomcat-stop .sh
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备份profile,并写入tomcat的catalina_home到环境变量,激活环境变量。
创建 tomcat-start.sh,内容如下:
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#!/bin/bash
##这里的catalina_base,是当前脚本的的父目录,如果不在catalina_base的子目录的话,记得修改
export catalina_base=$( cd $( dirname $0); cd .. ; pwd )
echo $catalina_base
tomcat_id=` ps aux | grep "java" | grep "dcatalina.base=$catalina_base " | grep - v "grep" | awk '{ print $2}' `
if [ -n "$tomcat_id" ] ; then
echo "tomcat($tomcat_id) still running now , please shutdown it first" ;
exit 2;
fi
tomcat_start_log=`$catalina_home /bin/startup .sh`
if [ "$?" = "0" ]; then
echo "shell script: $0"
echo "catalina_base: $catalina_base"
echo "tomcat thread: $tomcat_id"
echo "start succeed!!!"
else
echo "$0 $catalina_base start failed"
echo $tomcat_start_log
fi
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创建 tomcat-stop.sh,内容如下:
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#!/bin/bash
##这里的catalina_base,是当前脚本的的父目录,如果不在catalina_base的子目录的话,记得修改
export catalina_base=$( cd $( dirname $0); cd .. ; pwd )
echo $catalina_base
tomcat_id=` ps aux | grep "java" | grep "[d]catalina.base=$catalina_base " | awk '{ print $2}' `
if [ -n "$tomcat_id" ] ; then
tomcat_stop_log=`$catalina_home /bin/shutdown .sh`
else
echo "tomcat instance not found : $catalina_base"
exit
fi
if [ "$?" = "0" ]; then
echo "shell script: $0"
echo "catalina_base: $catalina_base"
echo "stop succeed!!!"
else
echo "$0 $catalina_base stop failed"
echo $tomcat_stop_log
fi
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复制两个tomcat:
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##完成删除lib和bin文件夹内容,生成空的bin文件夹
cp -r apache-tomcat-9.0.13 /data/apache-tomcat-test1 && cd /data/apache-tomcat-test1 && rm -rf lib/ bin/ && mkdir bin && cd -
##复制启动和停止脚本到bin文件夹,带权限复制
cp -p tomcat-start.sh tomcat-stop.sh /data/apache-tomcat-test1/bin/
##一个同样的tomcat目录,带权限复制
cp -rp /data/apache-tomcat-test1/ /data/apache-tomcat-test2/
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配置 server.xml 端口
你知道的,同一个服务器部署不同 tomcat 要设置不同的端口,不然会报端口冲突,所以我们只需要修改conf/server.xml中的其中前三个端口就行了。但它有四个分别是:
- server port:该端口用于监听关闭tomcat的shutdown命令,默认为8005
- connector http port:该端口用于监听http的请求,默认为8080
- connector ajp port:该端口用于监听ajp( apache jserv protocol )协议上的请求,通常用于整合apache server等其他http服务器,默认为8009
- redirect port:重定向端口,出现在connector配置中,如果该connector仅支持非ssl的普通http请求,那么该端口会把 https 的请求转发到这个redirect port指定的端口,默认为8443;
去掉注释的版本:
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<? xml version = "1.0" encoding = "utf-8" ?>
< server port = "8005" shutdown = "shutdown" >
< listener classname = "org.apache.catalina.startup.versionloggerlistener" />
< listener classname = "org.apache.catalina.core.aprlifecyclelistener" sslengine = "on" />
< listener classname = "org.apache.catalina.core.jrememoryleakpreventionlistener" />
< listener classname = "org.apache.catalina.mbeans.globalresourceslifecyclelistener" />
< listener classname = "org.apache.catalina.core.threadlocalleakpreventionlistener" />
< globalnamingresources >
< resource name = "userdatabase" auth = "container"
type = "org.apache.catalina.userdatabase"
description = "user database that can be updated and saved"
factory = "org.apache.catalina.users.memoryuserdatabasefactory"
pathname = "conf/tomcat-users.xml" />
</ globalnamingresources >
< service name = "catalina" >
< connector port = "8080" protocol = "http/1.1"
connectiontimeout = "20000"
redirectport = "8443" />
< connector port = "8009" protocol = "ajp/1.3" redirectport = "8443" />
< engine name = "catalina" defaulthost = "localhost" >
< realm classname = "org.apache.catalina.realm.lockoutrealm" >
< realm classname = "org.apache.catalina.realm.userdatabaserealm"
resourcename = "userdatabase" />
</ realm >
< host name = "localhost" appbase = "webapps"
unpackwars = "true" autodeploy = "true" >
< valve classname = "org.apache.catalina.valves.accesslogvalve" directory = "logs"
prefix = "localhost_access_log" suffix = ".txt"
pattern = "%h %l %u %t "%r" %s %b" />
</ host >
</ engine >
</ service >
</ server >
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tomcat-test1改为:
- server port:9015
- connector http port:9010
- connector ajp port:9019
tomcat-test2改为:
- server port:9025
- connector http port:9020
- connector ajp port:9029
修改标识:
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echo "test1" > /data/apache-tomcat-test1/webapps/root/index.jsp
echo "test2" > /data/apache-tomcat-test2/webapps/root/index.jsp
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修改完成,接着启动tomcat:
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/data/apache-tomcat-test1/bin/tomcat-start .sh
/data/apache-tomcat-test2/bin/tomcat-start .sh
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curl的时候是比较慢的,因为还没启动完成。启动完之后就好了。
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curl 127.0.0.1:9010
curl 127.0.0.1:9020
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这里注意访问端口是connector http port
对应的端口
4、后记
其实搭起来不太难,经过参考文章的思路,就是公用一个tomcat的lib和bin,这样子升级的时候替换lib即可,bin都同一用catalina_home的脚本,其实catalina_home下的bin下的start和shutdown脚本统一调用了catalina.sh,而单机多实例的则是巧妙运用了catalina.sh是通过环境中的catalina_home和catalina_base变量启动tomcat的
,通过改变catalina_base的路径达到同一条脚本启动tomcat在不同目录下
。
5、问题
5.1、tomcat启动慢
可以看到因为生成session id用了1分06秒,太久了,导致应用deploying整体的时间大大增加,这个问题是可以解决的,可以再启动的时候增加jvm参数-djava.security.egd=file:/dev/./urandom
,但是这样做应用产生随机数的能力被减弱,或者说随机不够均匀,对于经常使用加密的应用可能有安全影响。
修改一下启动脚本,添加了java_opts的设置,能使用java_opts,是因为catalina.sh会读出这个变量。
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#!/bin/bash
##这里的catalina_base,是当前脚本的的父目录,如果不在catalina_base的子目录的话,记得修改
export catalina_base=$( cd $( dirname $0); cd .. ; pwd )
echo $catalina_base
tomcat_id=` ps aux | grep "java" | grep "dcatalina.base=$catalina_base " | grep - v "grep" | awk '{ print $2}' `
export java_opts= "-djava.security.egd=file:/dev/./urandom" ;
if [ -n "$tomcat_id" ] ; then
echo "tomcat($tomcat_id) still running now , please shutdown it first" ;
exit 2;
fi
tomcat_start_log=`$catalina_home /bin/startup .sh`
if [ "$?" = "0" ]; then
echo "shell script: $0"
echo "catalina_base: $catalina_base"
echo "tomcat thread: $tomcat_id"
echo "start succeed!!!"
else
echo "$0 $catalina_base start failed"
echo $tomcat_start_log
fi
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5.2、远程ssh时,环境变量不生效问题
使用source命令刷新当前环境变量。
具体修改如下:
tomcat-start.sh :
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#!/bin/bash
##这里的catalina_base,是当前脚本的的父目录,如果不在catalina_base的子目录的话,记得修政
source /etc/profile
export catalina_base=$( cd $( dirname $0); cd .. ; pwd )
export java_opts= "-djava.security.egd=file:/dev/./urandom" ;
tomcat_id=` ps aux | grep "java" | grep "dcatalina.base=$catalina_base " | grep - v "grep" | awk '{ print $2}' `
echo "----------------------------------"
echo "using catalina_base:$catalina_base"
echo "using catalina_home:$catalina_home"
echo "----------------------------------"
if [ -n "$tomcat_id" ] ; then
echo "tomcat($tomcat_id) still running now , please shutdown it first" ;
exit 2;
fi
tomcat_start_log=`$catalina_home /bin/startup .sh`
if [ "$?" = "0" ]; then
echo "shell script: $0"
echo "tomcat thread: $tomcat_id"
echo "start succeed!!!"
else
echo "$0 $catalina_base start failed"
echo "catalina_base: $catalina_base"
echo $tomcat_start_log
fi
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tomcat-stop.sh
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#!/bin/bash
## 这里的catalina_base,是当前脚本的的父目录,如果不在catalina_base的子目录的话,记得修政
source /etc/profile
export catalina_base=$( cd $( dirname $0); cd .. ; pwd )
tomcat_id=` ps aux | grep "java" | grep "[d]catalina.base=$catalina_base " | awk '{ print $2}' `
echo "----------------------------------"
echo "using catalina_base:$catalina_base"
echo "using catalina_home:$catalina_home"
echo "----------------------------------"
if [ -n "$tomcat_id" ] ; then
tomcat_stop_log=`$catalina_home /bin/shutdown .sh`
else
echo "tomcat instance not found : $catalina_base"
exit
fi
if [ "$?" = "0" ]; then
echo "shell script: $0"
echo "stop succeed!!!"
else
echo "$0 $catalina_base stop failed"
echo "catalina_base: $catalina_base"
echo $tomcat_stop_log
fi
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附上restart脚本:tomcat-restart.sh :
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#!/bin/bash
source /etc/profile
export catalina_base=$( cd $( dirname $0); cd .. ; pwd )
green_color= '\e[1;32m' #绿
res= '\e[0m'
tomcat_id=` ps aux | grep "java" | grep "dcatalina.base=$catalina_base " | grep - v "grep" | awk '{ print $2}' `
sleep_time=1
echo "----------------------------------"
echo "using catalina_base:$catalina_base"
echo "using catalina_home:$catalina_home"
echo "----------------------------------"
if [ -n "$tomcat_id" ] ; then
echo -e "${green_color}found tomcat instance in pid $tomcat_id , shutdown now!${res}" ;
echo -e "${green_color}---------------start shutdown-------------------${res}"
source $( dirname $0) /tomcat-stop .sh;
echo -e "${green_color}--------------- end shutdown -------------------${res}"
fi
while [ -n "$tomcat_id" ]
do
sleep $sleep_time
echo wait "$sleep_time" s
tomcat_id=` ps aux | grep "java" | grep "dcatalina.base=$catalina_base " | grep - v "grep" | awk '{ print $2}' `
done
echo -e "${green_color}---------------start startup-------------------${res}"
source $( dirname $0) /tomcat-start .sh
echo -e "${green_color}---------------end startup-------------------${res}"
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参考博客:
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原文链接:https://blog.csdn.net/qq_26819733/article/details/84110648