tomcat单机多实例的实现
这篇文章主要介绍了tomcat单机多实例的实现,文中通过示例代码介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的朋友们下面随着小编来一起学习学习吧
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:
1 | apt-get install openjdk- 8 -jdk |
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
1 | wget http: //mirrors .hust.edu.cn /apache/tomcat/tomcat-9/v9 .0.13 /bin/apache-tomcat-9 .0.13. tar .gz |
解压tomcat:
1 | tar -xzvf apache-tomcat-9.0.13. tar .gz |
建一个程序目录:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | ##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 |
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:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | #!/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 $TOMCAT_START_LOG fi |
创建 tomcat-stop.sh,内容如下:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | #!/bin/bash ##这里的CATALINA_BASE,是当前脚本的的父目录,如果不在CATALINA_BASE的子目录的话,记得修改 export CATALINA_BASE=$( 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 |
复制两个tomcat:
1 2 3 4 5 6 7 8 | ##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/ |
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:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 | <? 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 > |
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:
1 2 | echo "test1" > /data/apache-tomcat-test1/webapps/ROOT/index.jsp echo "test2" > /data/apache-tomcat-test2/webapps/ROOT/index.jsp |
修改完成,接着启动tomcat:
1 2 | /data/apache-tomcat-test1/bin/tomcat-start .sh /data/apache-tomcat-test2/bin/tomcat-start .sh |
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。
1 2 | curl 127.0.0.1:9010 curl 127.0.0.1:9020 |
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。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | #!/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 $TOMCAT_START_LOG fi |
5.2、远程ssh时,环境变量不生效问题
使用source命令刷新当前环境变量。
具体修改如下:
tomcat-start.sh :
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 | #!/bin/bash ##这里的CATALINA_BASE,是当前脚本的的父目录,如果不在CATALINA_BASE的子目录的话,记得修政 source /etc/profile export CATALINA_BASE=$( 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 $TOMCAT_START_LOG fi |
tomcat-stop.sh
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 | #!/bin/bash ## 这里的CATALINA_BASE,是当前脚本的的父目录,如果不在CATALINA_BASE的子目录的话,记得修政 source /etc/profile export CATALINA_BASE=$( 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 $TOMCAT_STOP_LOG fi |
附上restart脚本:tomcat-restart.sh :
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 | #!/bin/bash source /etc/profile export CATALINA_BASE=$( 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}" |
参考博客:
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