Linux部署Java集群项目，实现负载均衡+高可用模式。

以你之姓@ 2023-06-15 13:26 24阅读 0赞

## Linux部署Java集群项目，实现负载均衡+高可用模式。 ##

## 0、环境 ##

系统：centos7
    Jdk：1.8
    Tomcat：8
    Ngxin+Keepalived

## 1、防火墙设置 ##

关闭防火墙或者放行端口

### 1.1关闭防火墙 ###

\#停止firewall  
systemctl stop firewalld.service

\#禁止firewall开机启动  
systemctl disable firewalld.service

\#查看默认防火墙状态（关闭后显示notrunning，开启后显示running）  
firewall-cmd --state

### 1.2加入放行端口 ###

\#添加放行端口(–permanent永久生效，没有此参数重启后失效)  
firewall-cmd --zone=public --add-port=80/tcp --permanent  
firewall-cmd --zone=public --add-port=8080/tcp --permanent

\#刷新防火墙 使其生效  
firewall-cmd --reload

\#查看开发的端口  
firewall-cmd --zone=public --list-ports

## 2、安装JDK ##

\#查看java列表  
yum -y list java\*

\#安装1.8.0 openjdk（或者官网下载jdk）  
yum -y install java-1.8.0-openjdk

\#JDK默认安装路径/usr/lib/jvm  
ls /usr/lib/jvm  
![在这里插入图片描述][20191122164057813.png]  
\#环境变量配置  
vi /etc/profile

\#将如下配置添加至文件中，然后保存退出。

# set java environment  
    JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.232.b09-0.el7_7.x86_64
    PATH=$PATH:$JAVA_HOME/bin  
    CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar  
    export JAVA_HOME  CLASSPATH  PATH

\#保存关闭profile文件，执行如下命令生效  
source /etc/profile

\#使用如下命令，查看JDK变量  
echo $JAVA\_HOME  
echo $PATH  
echo $CLASSPATH  
![在这里插入图片描述][20191122164117486.png]

## 3、装tomcat8 ##

### 3.1 安装wget ###

yum -y install wget

### 3.2下载tomcat8 ###

cd /usr/local  
wget http://mirrors.tuna.tsinghua.edu.cn/apache/tomcat/tomcat-8/v8.5.47/bin/apache-tomcat-8.5.47.tar.gz  
\#解压  
tar -zxvf apache-tomcat-8.5.47.tar.gz

\#移动重命名  
mv apache-tomcat-8.5.47 /usr/local/tomcat

### 3.3配置jdk到tomcat ###

\#修改配置文件  
vi /usr/local/tomcat/bin/catalina.sh

\#在 OS specific support. 前面加入如下代码  
JAVA\_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.232.b09-0.el7\_7.x86\_64  
JRE\_HOME=$JAVA\_HOME/jre

### 3.4配置tomcat开机启动 ###

\#创建tomcat.service文件  
vi /usr/lib/systemd/system/tomcat.service

[Unit]
    Description=Tomcat
    After=syslog.target network.target remote-fs.target nss-lookup.target
    
    [Service]
    Type=oneshot
    ExecStart=/usr/local/tomcat/bin/startup.sh
    ExecStop=/usr/local/tomcat/bin/shutdown.sh
    ExecReload=/bin/kill -s HUP $MAINPID
    RemainAfterExit=yes
    
    [Install]
    WantedBy=multi-user.target

\#允许tomcat开机启动  
systemctl enable tomcat

### 3.5 tomcat常见命令 ###

\#启动tomcat  
systemctl start tomcat.service

\#关闭tomcat  
systemctl stop tomcat.service

\#重启tomcat  
systemctl restart tomcat.service

\#查看状态tomcat  
systemctl status tomcat.service

## 4、nginx负载均衡 ##

**备注：nginx 负载均衡参数ip\_hash：实现同一ip地址下访问项目为同一个服务器，实现session共享机制，缺点：当服务器挂了，已在访问该服务器的用户请求会失效，需要重新访问项目。**

### 4.1 分别在3台服务器上安装nginx ###

yum install -y gcc-c++ pcre pcre-devel zlib zlib-devel openssl openssl-devel

cd /usr/local/

wget https://nginx.org/download/nginx-1.13.4.tar.gz

tar -zxvf nginx-1.13.4.tar.gz

cd nginx-1.13.4

./configure --prefix=/etc/nginx  
make  
make install

\#创建日志目录  
mkdir -p /home/bdxhdata/nginx/logs

\#修改配置  
whereis nginx  
cd /etc/nginx/conf

> nginx.conf
    vi nginx.conf

**nginx.conf：(配置信息)**

worker_processes  1;
    error_log  /home/bdxhdata/nginx/logs/nginx-error.log;
    
    events {
        worker_connections  1024;
    }
    
    http {
        include       mime.types;
        default_type  application/octet-stream;
    
        log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                          '$status $body_bytes_sent "$http_referer" '
                          '"$http_user_agent" "$http_x_forwarded_for"';
    
        access_log  /home/bdxhdata/nginx/logs/nginx-access.log  main;
        sendfile        on;
        keepalive_timeout  65;
    
    upstream bdxh{  
    ip_hash;
    	server 192.168.100.11:8080;
    	server 192.168.100.12:8080;
       	server 192.168.100.13:8080;
        }
       server {  
    	listen       80;  
    	server_name  localhost;  
    	#charset koi8-r;  
    	#access_log  logs/host.access.log  main;  
    	location /rsv {  
    	    proxy_pass   http://bdxh;  
    	    index  index.html index.htm;  
    	}
    
            error_page   500 502 503 504  /50x.html;
            location = /50x.html {
                root   html;
            }
    
    	location = /favicon.ico {
    	    log_not_found off;
    	    access_log off;
    	}
        }
    }

\#启动nginx  
/etc/nginx/sbin/nginx

\#重启nginx  
/etc/nginx/sbin/nginx -s stop  
/etc/nginx/sbin/nginx

\#查看ip占用  
yum -y install net-tools  
netstat -tunlp

## 5、安装keepalived实现高可用 ##

### 5.1 下载与配置 ###

yum -y install keepalived
    
    > /etc/keepalived/keepalived.conf
    vi /etc/keepalived/keepalived.conf

**\#keepalived.conf 配置：(主服务器配置:state MASTER)**

! Configuration File for keepalived
    global_defs {
    	router_id jackfang
    }
    
    vrrp_script check_nginx {
        script "/etc/keepalived/nginx_check.sh"         
        interval 2                            
        weight 2                  
    }
    vrrp_instance VI_1 {
        state MASTER
        interface ens33
        virtual_router_id 100
        priority 100
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass 1111
        }
        track_script {
            check_nginx
        }
        virtual_ipaddress {
            192.168.100.10
        }
    }

**\#keepalived.conf 配置：(备服务器配置)**  
state MASTER 改为state BACKUP  
priority 100 改小 priority 99

### 5.2 创建检测nginx脚本 ###

vi /etc/keepalived/nginx\_check.sh

#!/bin/bash
    A=`netstat -tunlp|grep 80|wc -l`
    if [ $A -eq 0 ];then
    /etc/nginx/sbin/nginx
    sleep 2
    if [ `netstat -tunlp|grep 80|wc -l` -eq 0 ];then
            killall keepalived
    fi
    fi

chmod +x /etc/keepalived/nginx\_check.sh

service keepalived start  
service keepalived restart  
service keepalived stop  
\#查看keepalived运行状态  
service keepalived status  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZhbmdjaGFvMjAxMQ_size_16_color_FFFFFF_t_70]  
mkdir -p /etc/sysconfig/

cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/  
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/  
ln -s /usr/local/sbin/keepalived /usr/sbin/  
ln -s /usr/local/keepalived/sbin/keepalived /sbin/

\#启动keepalived  
/usr/local/keepalived/sbin/keepalived

## 6、部署RSV（JavaWeb项目）项目到tomcat ##

### 6.1 将打包好的项目移动到webapps文件夹下 ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZhbmdjaGFvMjAxMQ_size_16_color_FFFFFF_t_70 1]

\#重启tomcat服务  
service tomcat restart

### 6.2 测试访问rsv项目 ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZhbmdjaGFvMjAxMQ_size_16_color_FFFFFF_t_70 2]

\#测试当停止11、12 其中一台服务器时，仍然能访问成功表示实现了高可用配置。

[20191122164057813.png]: https://img-blog.csdnimg.cn/20191122164057813.png
[20191122164117486.png]: https://img-blog.csdnimg.cn/20191122164117486.png
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