Tomcat介绍与实验

Tomcat 服务器是一个免费的开放源代码的Web 应用服务器，属于轻量级应用服务器，在中小型系统和并发访问用户不是很多的场合下被普遍使用，Tomcat 具有处理HTML页面的功能，它还是一个Servlet和 JSP容器。

一.Tomcat安装部署

1.下载安装包

bash 复制代码

[root@RS1 ~]# wget https://dlcdn.apache.org/tomcat/tomcat-9/v9.0.115/bin/apache-tomcat-9.0.115.tar.gz

2.部署tomcat

bash 复制代码

[root@RS1 local]# yum install java-1.8.0-openjdk.x86_64 -y
[root@RS1 ~]# tar zxf apache-tomcat-9.0.115.tar.gz  -C /usr/local
[root@RS1 ~]# cd /usr/local/
[root@RS1 local]# ls
bin  etc  games  include  lib  lib64  libexec  sbin  share  src  tomcat-9.0-doc
[root@RS1 local]# mv apache-tomcat-9.0.115/ tomcat
[root@RS1 local]# cd tomcat/
[root@RS1 tomcat]# ls
bin           conf             lib      logs    README.md      RUNNING.txt  webapps
BUILDING.txt  CONTRIBUTING.md  LICENSE  NOTICE  RELEASE-NOTES  temp         work


[root@RS1 tomcat]# cd bin/
[root@RS1 bin]# ./startup.sh
Using CATALINA_BASE:   /usr/local/tomcat
Using CATALINA_HOME:   /usr/local/tomcat
Using CATALINA_TMPDIR: /usr/local/tomcat/temp
Using JRE_HOME:        /usr
Using CLASSPATH:       /usr/local/tomcat/bin/bootstrap.jar:/usr/local/tomcat/bin/tomcat-juli.jar
Using CATALINA_OPTS:
Tomcat started.
[root@RS1 bin]# netstat -antlupe | grep 8080

3.制作tomcat的启动脚本

bash 复制代码

[root@RS1 bin]# vim /usr/local/tomcat/conf/tomcat.conf
JAVA_HOME=/etc/alternatives/jre
#为 Tomcat 服务指定 Java 运行环境。
[root@RS1 bin]# vim /lib/systemd/system/tomcat.service
[Unit]
Description=Tomcat
#After=syslog.target network.target remote-fs.target nss-lookup.target
After=syslog.target network.target

[Service]
Type=forking
EnvironmentFile=/usr/local/tomcat/conf/tomcat.conf
ExecStart=/usr/local/tomcat/bin/startup.sh
ExecStop=/usr/local/tomcat/bin/shutdown.sh
PrivateTmp=true
User=tomcat
Group=tomcat

[Install]
WantedBy=multi-user.target

#创建了一个无法登录、没有家目录的 tomcat 用户，专门用于运行 Tomcat 服务，符合最小权限原则。
[root@RS1 bin]# useradd  -s /sbin/nologin -M tomcat

#将 Tomcat 安装目录的所有权递归地交给 tomcat 用户和组，确保服务进程有足够的权限读写自身文件。
[root@RS1 bin]# chown  tomcat.tomcat /usr/local/tomcat/ -R
通知 systemd 守护进程重新加载配置文件，使新的 tomcat.service 生效。
[root@RS1 bin]# systemctl daemon-reload
[root@RS1 bin]# systemctl enable --now tomcat

[root@RS1 bin]# systemctl start tomcat
[root@RS1 bin]# netstat -antlupe | grep java
tcp6       0      0 127.0.0.1:8005          :::*                    LISTEN      1000       139979     10682/java
tcp6       0      0 :::8080                 :::*                    LISTEN      1000       140563     10682/java

二.Nginx与tomcat的整合

1.单体架构

bash 复制代码

[root@nginx conf.d]# vim /usr/local/nginx/conf/nginx.conf
include "/usr/local/nginx/conf/conf.d/*.conf";

[root@Nginx conf.d]# cd /usr/local/nginx/conf/conf.d/
[root@Nginx conf.d]# vim vhosts.conf
server {
    listen 80;
    server_name app.timinglee.org;
    location ~* \.jsp$ {
        proxy_pass http://172.25.254.10:8080;
    }
}

[root@RS1 ~]# cp test.jsp  /usr/local/tomcat/webapps/ROOT/
[root@RS1 ~]# scp test.jsp  root@172.25.254.20:/usr/local/tomcat/webapps/ROOT/

[root@Nginx conf.d]# nginx  -s reload

测试访问：

2.tomcat负载均衡

bash 复制代码

[root@nginx ~]# vim /usr/local/nginx/conf/conf.d/vhosts.conf
upstream tomcat {
    hash $cookie_JSESSIONID;
    server 172.25.254.10:8080;
    server 172.25.254.20:8080;
}
server {
    listen  80;
    server_name app.timinglee.org;
    location ~* \.jsp$ {
        proxy_pass http://tomcat;
    }
}
[root@Nginx conf.d]# nginx  -s reload

测试：

三.tomcat+memcache实现session会话零丢失

1.tomcat加载模块

bash 复制代码

[root@RS1 ~]# unzip jar.zip
[root@RS1 ~]# cd jar/
[root@RS1 jar]# cp * /usr/local/tomcat/lib/
[root@RS1 jar]# scp * root@172.25.254.20:/usr/local/tomcat/lib/

2.安装memcache

bash 复制代码

[root@RS1 jar]# dnf install memcached -y
[root@RS2 ~]# dnf install memcached -y

[root@RS1 ~]# vim /etc/sysconfig/memcached
[root@RS2 ~]# vim /etc/sysconfig/memcached

PORT="11211"
USER="memcached"
MAXCONN="1024"
CACHESIZE="64"
OPTIONS="-l 0.0.0.0,::1"

[root@RS1+2 ~]# systemctl start memcached.service
[root@RS1+2 ~]# netstat -antluple | grep memcached

3.配置tomcat

bash 复制代码

[root@RS1 ]#  vim /usr/local/tomcat/conf/context.xml

<Context>

    <!-- Default set of monitored resources. If one of these changes, the    -->
    <!-- web application will be reloaded.                                   -->
    <WatchedResource>WEB-INF/web.xml</WatchedResource>
    <WatchedResource>WEB-INF/tomcat-web.xml</WatchedResource>
    <WatchedResource>${catalina.base}/conf/web.xml</WatchedResource>

    <!-- Uncomment this to disable session persistence across Tomcat restarts -->
    <!--
    <Manager pathname="" />
    -->
   <Manager className="de.javakaffee.web.msm.MemcachedBackupSessionManager"
    memcachedNodes="n1:172.25.254.10:11211,n2:172.25.254.20:11211"
    failoverNodes="n1"
    requestUriIgnorePattern=".*\.(ico|png|gif|jpg|css|js)$"
    		  transcoderFactoryClass="de.javakaffee.web.msm.serializer.kryo.KryoTranscoderFactory"
    />

</Context>

[root@RS2 ]#  vim /usr/local/tomcat/conf/context.xml

<Context>

    <!-- Default set of monitored resources. If one of these changes, the    -->
    <!-- web application will be reloaded.                                   -->
    <WatchedResource>WEB-INF/web.xml</WatchedResource>
    <WatchedResource>WEB-INF/tomcat-web.xml</WatchedResource>
    <WatchedResource>${catalina.base}/conf/web.xml</WatchedResource>

    <!-- Uncomment this to disable session persistence across Tomcat restarts -->
    <!--
    <Manager pathname="" />
    -->
   <Manager className="de.javakaffee.web.msm.MemcachedBackupSessionManager"
    memcachedNodes="n1:172.25.254.10:11211,n2:172.25.254.20:11211"
    failoverNodes="n2"
    requestUriIgnorePattern=".*\.(ico|png|gif|jpg|css|js)$"
    transcoderFactoryClass="de.javakaffee.web.msm.serializer.kryo.KryoTranscoderFactory"
    />

</Context>
[root@RS1 ~]#  systemctl restart tomcat.service
[root@RS2 ~]#  systemctl restart tomcat.service

RS1:

RS2: