Nginx+Tomcat+keepalived dynamic and static separation high-availability load balancing cluster

Nginx+Tomcat+keepalived

Nginx+Tomcat

1. Introduction to Nginx

Supports responses of up to 50,000 concurrent connections.
Has strong static resource processing capabilities
. Stable operation
. System resource consumption such as memory and CPU is very low.
At present, many large websites use Nginx server as a reverse proxy and load balancer for back-end website programs to improve Load concurrency of the entire site

2.Nginx dynamic and static separation principle

Match through the location field.
If it is a file ending in .html, it will be sent to local processing.
If it is ending in .jsp, it will be sent to tomcat.

3.Tomcat important directory

table of Contents	effect
bin	Store startup and shutdown Tomcat scripts
conf	Store different configuration files of Tomcat
doc	Store Tomcat documents
lib	Store the library files needed for Tomcat to run
logs	Store the log file when Tomcat is executed
src	Store the source code of Tomcat
webapps	Tomcat's main web publishing directory
work	Store the class files generated after jsp compilation

NFS storage server deployment

1. Install nfs-utils, rpcbind software package

yum -y install nfs-utils rpcbind

2. Create a shared directory

mkdir /opt/tomcat1
mkdir /opt/tomcat2

Edit a javascript test page and upload pictures

vim /opt/tomcat1/index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<html>
<head>
<title>JSP web1 test</title>
</head>
<body>
<% out.println("Welcome to test site");%>
<div>动态页面</div><br/><img src="web1.jpg" />
</body>
</html>

vim /opt/tomcat2/index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<html>
<head>
<title>JSP web2 test</title>
</head>
<body>
<% out.println("Welcome to test2 site");%>
<div>动态页面</div><br/><img src="web2.jpg" />
</body>
</html>

3. Shared directory

vi /etc/exports

/opt/tomcat1 192.168.2.16(ro)
/opt/tomcat2 192.168.2.17(ro)

View mount

showmount -e

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web cluster

Configure Java environment variables

1.xftp upload two files,
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decompress and move

tar xf jdk-8u91-linux-x64.tar.gz
mv jdk1.8.0_91/ /usr/local/java

2. Configure environment variables

vi /etc/profile

Add to

export JAVA_HOME=/usr/local/java
export JAVA_JRE=/usr/local/java/jre
export PATH=$PATH:$JAVA_HOME/bin:$JAVA_HOME/lib:$JAVA_JRE/bin:$JAVA_JRE/lib

Execute and view

source /etc/profile
echo $PATH

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test

View version

java -version

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Edit a .java file to test

vim HelloWorld.java

public class HelloWorld {
    
    
        public static void main (String[] args) {
    
    
                System.out.println("helloworld!");
        }
}

javac HelloWorld.java
java HelloWorld

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Deploy Tomcat

1. Unzip, move

tar xf apache-tomcat-8.5.16.tar.gz

mv apache-tomcat-8.5.16 /usr/local/tomcat8

2. Establish a soft connection

ln -s /usr/local/tomcat8/bin/startup.sh /usr/bin/tomcatup
ln -s /usr/local/tomcat8/bin/shutdown.sh /usr/bin/tomcatdown
ln -s /usr/local/tomcat8/conf/server.xml /etc/tomcat.xml

After linking

tomcatup: Turn on tomcat
tomcatdown: Turn off tomcat
/etc/tomcat.xml: Configuration file

Open tomcat

tomcatup

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Check if it's on

netstat -anpt | grep java

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Test tomcat

1. Create a web directory

mkdir -p /tomcat/web

2. Mount nfs to a local directory

tomcat1

mount 192.168.2.18:/opt/tomcat1 /tomcat/web

tomcat2

mount 192.168.2.18:/opt/tomcat2 /tomcat/web

Check the mounting situation
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3. Set the website root directory

Edit configuration file

vi /etc/tomcat.xml

   <Context docBase="/tomcat/web" path="" reloadable="false">
      </Context>

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4. Access test

Reboot

curl http://localhost:8080

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scheduler

Upload nginx-1.12.2.tar.gz, keepalived-2.0.13.tar.gz

Compile and install nginx

yum install dependencies

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

Create a non-loginable account for ngxin to use

useradd -M -s /sbin/nologin nginx

Unzip

tar xf nginx-1.12.2.tar.gz

cd nginx-1.12.2/

Configuration content

 ./configure \
--prefix=/usr/local/nginx \
--user=nginx \
--group=nginx \
--with-http_stub_status_module

Compile and install

make && make install -j 8

Establish nginx soft connection

ln -s /usr/local/nginx/sbin/nginx /usr/local/sbin/

Nginx configuration file soft connection

ln -s /usr/local/nginx/conf/nginx.conf /etc/

Check that nginx can run normally

nginx -t

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View nginx status

netstat -anpt | grep nginx

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No prompt is not started

Start nginx

nginx

Restart nginx

killall -1 nginx

Close nginx

killall -3 nginx

Add to

upstream服务池
upstream tomcat_server {
            server 192.168.2.16:8080 weight=1;
             节点      ip地址  端口号  权重
            server 192.168.2.17:8080 weight=1;
}

       location ~ \.jsp$ {
            proxy_pass http://tomcat_server;  
}                                          服务地址池名

The pictures linked in jsp should be uploaded to the nginx root directory. If the pictures are not uploaded, they will not be loaded.
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Install keepalived

xftp upload keepalived file, unzip

tar xf keepalived-2.0.13.tar.gz

Install compilation tools and plugins

yum -y install gcc gcc-c++ make popt-devel kernel-devel openssl-devel

Switch directory, compile and install

cd keepalived-2.0.13/

./configure --prefix=/

make && make install

Join the system management service, set it to start automatically after booting

cp keepalived/etc/init.d/keepalived /etc/init.d/

systemctl enable keepalived.service

Edit the main scheduler configuration file

vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived
global_defs {
   router_id Nginx_01
   }

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 150
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.2.100
    }
}
}

Edit alternate scheduler configuration file

vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id Nginx_02
   }

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 140
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.2.100
    }
}

Reboot

test

ip addr test the
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main route scheduler failure test, disable the network card, or disable keepalived

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Restart keepalived

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Nginx monitoring script

The role of the script is to turn off keepalived when there is a problem with the nginx service.
Assuming that the main scheduler is only a problem with the Nginx service, and everything else (keepalived) is normal, then the VIP will not jump to the backup scheduler, and the backup scheduler cannot be enabled. , The following situation will appear

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Edit the keepalived configuration file and add the following content

! Configuration File for keepalived

global_defs {
   router_id Nginx_01
   }

vrrp_script chk_nginx {
    script "/etc/keepalived/nginx_check.sh"
    interval 2
    weight -20
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 150
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
    chk_nginx
    }

    virtual_ipaddress {
        192.168.2.100
    }
}

Edit script

vi /etc/keepalived/nginx_check.sh

#!/bin/bash
A=`ps -C nginx --no-header |wc -l`
if [ $A -eq 0 ];then
killall -3 nginx
nginx
if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
/etc/init.d/keepalived stop
fi
fi

The function of the script is to detect the status of nginx, if it is closed, it will be reopened, and then checked again, if it fails, keepalived will be closed.