Tomcat multi instance and load balancing

Tomcat multi instance

Install the jdk

jdk must be installed before deploying tomcat, because jdk is the necessary environment for Tomcat to run.

1. # turn off the firewall

systemctl stop firewalld
systemctl disable firewalld
setenforce 0

2. # transfer the software package required to install Tomcat to the / opt directory
apache-tomcat-9.0.16.tar.gz
jdk-8u201-linux-x64.rpm

3. # switch to / opt and install JDK
cd /opt
rpm -ivh jdk-8u201-linux-x64.rpm

4. # view the java version
java -version

Install tomcat

1. # switch to / opt and unzip the tomcat package
cd /opt
tar -zxf apache-tomcat-9.0.16.tar.gz

2. # create a new folder / usr/local/tomcat
mkdir /usr/local/tomcat

3. # copy the unzipped package to / usr/local / and rename it
cp -a apache-tomcat-9.0.16 /usr/local/tomcat/tomcat1
cp -a apache-tomcat-9.0.16 /usr/local/tomcat/tomcat2

Configure tomcat environment variables

vim /etc profile

export JAVA_HOME=/usr/java/jdk1.8.0_201-amd64
export CLASSPATH=$JAVA_HOME/lib/tools.jar:$JAVA_HOME/lib/dt.jar
export PATH=$JAVA_HOME/bin:$PATH

Modify the main configuration file in tomcat2

vim /usr/local/tomcat/tomcat2/conf/server.xml

22 <Server port="8006" shutdown="SHUTDOWN">
69 <Connector port="8081" protocol="HTTP/1.1"
116 <Connector port="8010" protocol="AJP/1.3" redirectPort="8443" />

Modify startup and shutdown scripts

1. # modify / usr / local / Tomcat / tomcat1 / bin / startup sh
vim /usr/local/tomcat/tomcat1/bin/startup.sh

export CATALINA_HOME1=/usr/local/tomcat/tomcat1
export CATALINA_BASE1=/usr/local/tomcat/tomcat1
export TOMCAT_HOME1=/usr/local/tomcat/tomcat1

2. # modify / usr / local / Tomcat / tomcat1 / bin / shutdown of tomcat1 sh
vim /usr/local/tomcat/tomcat1/bin/shutdown.sh

export CATALINA_HOME1=/usr/local/tomcat/tomcat1
export CATALINA_BASE1=/usr/local/tomcat/tomcat1
export TOMCAT_HOME1=/usr/local/tomcat/tomcat1

3. # modify / usr / local / Tomcat / tomcat2 bin / startup sh
vim /usr/local/tomcat/tomcat2/bin/startup.sh

export CATALINA_HOME1=/usr/local/tomcat/tomcat2
export CATALINA_BASE1=/usr/local/tomcat/tomcat2
export TOMCAT_HOME1=/usr/local/tomcat/tomcat2

4. # modify / usr / local / Tomcat / tomcat2 / bin / shutdown sh
vim /usr/local/tomcat/tomcat2/bin/shutdown.sh

export CATALINA_HOME1=/usr/local/tomcat/tomcat2
export CATALINA_BASE1=/usr/local/tomcat/tomcat2
export TOMCAT_HOME1=/usr/local/tomcat/tomcat2

Start tomcat and view

1. # start tomcat1
cd /usr/local/tomcat/
./tomcat1/bin/startup.sh

2. # start tomcat2
./tomcat2/bin/startup.sh

3. # check whether the startup is successful
ss -ntap|grep java
http://192.168.80.130:8080/

Nginx+Tomcat load balancing, dynamic and static separation

In the standalone mode, Tomcat runs alone and directly accepts user requests. It is not recommended. The reverse agent, running on a single machine, provides an nginx as the reverse agent, which can provide static response from nginx and dynamic jsp proxy to Tomcat
LNMT: Linux + Nginx + MySQL + Tomcat
LAMT: Linux + Apache(Httpd)+ MySQL + Tomcat

In front of one Nginx, reverse proxy and load balancing scheduling are performed for multiple Tomcat instances. The pure dynamic pages deployed on Tomcat are more suitable
LNMT: Linux + Nginx + MySQL + Tomcat
Multilevel agent
LNNMT: Linux + Nginx + Nginx + MySQL + Tomcat

The problem with dynamic servers is that the concurrency capability is too weak, and multiple dynamic servers are often required to provide services together. How to allocate concurrent pressure requires scheduling. A certain scheduling strategy is adopted to distribute requests to different servers, which is Load Balance.

When single machine Tomcat evolves multi machine and multi-level deployment, a problem is highlighted, which is Session. The origin of this problem is that the HTTP protocol did not think of the future development at the beginning of its design.

Deploy Nginx load balancer

Environmental profile:

ngnix: 192.168.80.130

tomcat1: 192.168.80.133

tomcat2: 192.168.80.129

1. #Turn off firewall
systemctl stop firewalld
setenforce 0

2. #Install dependency package
yum -y install pcre-devel zlib-devel gcc gcc-c++ make

3. #Create new users and groups for easy management
useradd -M -s /sbin/nologin nginx

4. #Switch to the opt directory and transfer the downloaded compressed package to extract it
cd /opt
tar -zxf nginx-1.12.0.tar.gz 

4. #Switch to the decompressed directory and compile
cd nginx-1.12.0

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

5. #install
make && make install -j4

6. #Make a soft connection and let the system recognize the operation commands of nginx
ln -s /usr/local/nginx/sbin/nginx /usr/local/sbin/

7. #Add nginx command to service
cd /lib/systemd/system
vim nginx.service
#!/bin.bash
[Unit]
Description=nginx
After=network.target
[Service]
Type=forking
PIDFile=/usr/local/nginx/logs/nginx.pid
ExecStart=/usr/local/nginx/sbin/nginx
ExecReload=/usr/bin/kill -s HUP $MAINPID
ExecStop=/usr/bin/kill -s QUIT $MAINPID
PrivateTmp=true
[Install]
WantedBy=multi-user.target

8. #Reload the unit Start service
systemctl daemon-reload 
systemctl start nginx

9. #See if it started successfully
ss -ntap|grep nginx
http://192.168.80.130/

Deploy the first Tomcat

192.168.80.129

1. #Turn off firewall
systemctl stop firewalld
setenforce 0

2. #Switch to / opt and transfer the software packages required to install Tomcat to the / opt directory
apache-tomcat-9.0.16.tar.gz 
jdk-8u201-linux-x64.rpm

3. #Install JDK
rpm -ivh jdk-8u201-linux-x64.rpm 

4. #Modify the variable configuration file
vim /etc/profile
export JAVA_HOME=/usr/java/jdk1.8.0_201-amd64
export CLASSPATH=$JAVA_HOME/lib/tools.jar:$JAVA_HOME/lib/dt.jar
export PATH=$JAVA_HOME/bin:$PATH

5. #Refresh profile
source /etc/profile

6. #Switch to / opt and unzip the tomcat package
cd /opt
tar -zxf apache-tomcat-9.0.16.tar.gz 

7. #Copy the extracted package to / usr/local / and rename it
cp -r apache-tomcat-9.0.16 /usr/local/tomcat

8. #Add user set primary group
useradd -s /sbin/nologin tomcat
chown tomcat:tomcat /usr/local/tomcat -R


9. #New service file
vim /etc/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
ExecStart=/usr/local/tomcat/bin/startup.sh
ExecStop=/usr/local/tomcat/bin/shutdown.sh
RestartSec=3
PrivateTmp=true
User=tomcat
Group=tomcat

[Install]
WantedBy=multi-user.target

10. #Reload the service and start it to see if it starts successfully

systemctl daemon-reload
systemctl start tomcat
ss -ntap |grep 8080



#############New dynamic page site###########3

11. #Switch to webapp and create a new test directory
cd /usr/local/tomcat/webapps/
mkdir test

12. #Create dynamic page file
vim test/index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<html>
  <head>
     <title>JSP test1 page </title>
  </head>
  <body>
     <% out.println("Dynamic page 1,http://www.test1.com");%>
  </body>
</html>

13. #Modify master profile
vim /usr/local/tomcat/conf/server.xml
 Delete the original site module
 add to
<Host name="localhost" appBase="webapps"
            unpackWARs="true" autoDeploy="true" xmlValidation="false"
            xmlNamespaceAware="false">
                <Context docBase="/usr/local/tomcat/webapps/test"
                path="" reloadable="true" />
      </Host>


14. #Restart the service and test it on the web page
systemctl restart tomcat.service 
http://192.168.80.129:8080/

Deploy the second Tomcat

1. #Turn off firewall
systemctl stop firewalld
setenforce 0

2. #Switch to / opt and transfer the software packages required to install Tomcat to the / opt directory
apache-tomcat-9.0.16.tar.gz 
jdk-8u201-linux-x64.rpm

3. #Install JDK
rpm -ivh jdk-8u201-linux-x64.rpm 

4. #Modify environment variable configuration file
vim /etc/profile
export JAVA_HOME=/usr/java/jdk1.8.0_201-amd64
export CLASSPATH=$JAVA_HOME/lib/tools.jar:$JAVA_HOME/lib/dt.jar
export PATH=$JAVA_HOME/bin:$PATH

5. #Refresh profile
source /etc/profile

6. #Switch to / opt and unzip the tomcat package
cd /opt
tar -zxf apache-tomcat-9.0.16.tar.gz 

7. #Copy the extracted package to / usr/local / and rename it
cp -r apache-tomcat-9.0.16 /usr/local/tomcat

8. #Add user set primary group
useradd -s /sbin/nologin tomcat
chown tomcat:tomcat /usr/local/tomcat -R


9. #New service file
vim /etc/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
ExecStart=/usr/local/tomcat/bin/startup.sh
ExecStop=/usr/local/tomcat/bin/shutdown.sh
RestartSec=3
PrivateTmp=true
User=tomcat
Group=tomcat

[Install]
WantedBy=multi-user.target

10. #Reload the service and start it to see if it starts successfully

systemctl daemon-reload
systemctl start tomcat
ss -ntap |grep 8080



#############New dynamic page site###########3

11. #Switch to webapp and create a new test directory
cd /usr/local/tomcat/webapps/
mkdir test

12. #Create dynamic page file
vim test/index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<html>
  <head>
     <title>JSP test2 page </title>
  </head>
  <body>
     <% out.println("Dynamic page 2,http://www.test2.com");%>
  </body>
</html>

13. #Modify master profile
vim /usr/local/tomcat/conf/server.xml
 Delete the original site module
 add to
<Host name="localhost" appBase="webapps"
            unpackWARs="true" autoDeploy="true" xmlValidation="false"
            xmlNamespaceAware="false">
                <Context docBase="/usr/local/tomcat/webapps/test"
                path="" reloadable="true" />
      </Host>


14. #Restart the service and test it on the web page
systemctl restart tomcat.service 
http://192.168.80.133:8080/

nginx configuration

Prepare static pages and pictures

1. #Switch to / usr/local/nginx/html /
cd /usr/local/nginx/html/

2. #Create a test folder and create a static web page in it
mkdir test
cd test
vim test.html
this is static test web !!

3. #Drag a picture to test and rename it 1 jpg
mv 1.jfif 1.jpg

4. #Configure master profile
vim /usr/local/nginx/conf/nginx.conf

#Configure the load balancing server list. The weight parameter indicates the weight. The higher the weight, the greater the probability of being assigned  
#gzip  on;  
    upstream tomcat_server {
                    server 192.168.59.105:8080 weight=1;
                    server 192.168.59.118:8080 weight=1;
                 
                    }
                    
                    
#Dynamic and static separation
 location ~ .*\.jsp$ {
          proxy_pass http://tomcat_server;
          proxy_set_header HOST $host;
          proxy_set_header X-Real-IP $remote_addr;
          proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
     }

#Static picture regularization
         location ~* .*\.(jpg|html|png|gif)$ {
         root /usr/local/nginx/html/test;
     }


         location / {
            root   html;
            index  index.html index.htm;
     }



5.  #Restart nginx and test
http://192.168.80.130/1.jpg
http://192.168.80.130/test.html

Keywords: Operation & Maintenance Load Balance Tomcat

Added by alimadzi on Thu, 20 Jan 2022 19:11:58 +0200

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