Nginx+Tomcat load balancing

Introduction to knowledge part
: As we all know, Nginx, as a lightweight HTTP server, has the advantages of high concurrent processing and low resource consumption. However, Nginx, like Apache, has great advantages in processing static pages, while processing dynamic pages is not as good as Tomcat. We can solve this problem by separating static and dynamic pages with Nginx and Tomcat.
Tomcat: It is a free and open source Web lightweight application server. It is used in small and medium-sized systems and environments with less concurrent access. It is the first choice for developing and debugging JSP programs. Generally speaking, Tomcat has the same ability to process static page HTML as Apache and Nginx, but it is far inferior to Apache and Nginx in this respect, so Tomcat usually runs as a Servlet and JSP container on the backend alone.
Operation steps
In this case, we need to use one Nginx server and two Tomcat servers

1. For the installation and configuration of Nginx server, please refer to this document:
http://blog.51cto.com/13434336/2102925
2. Tomcat part. Mount the CD and install the JDK. JDK is a Java language development kit provided by Sun for free, which contains the Java Virtual Machine (JVM), which can interpret Java bytecodes and ensure the cross-platform nature of Java.

3. Create a Java.sh script under /etc/profile.d/

4. Import the script into the environment variable to make it effective.

5. Use java -version to view the Java version, which also means that the installation was started successfully.

6. Install Tomcat.

7. Create a Java web site and make a web page.

The web page is made as shown below

8. Modify the Tomcat main configuration file /usr/local/tomcat7/conf/server.xml. Find the location and add the following two lines

9. Start the Tomcat service. (shudown.sh is used to stop Tomcat, and startup.sh is used to start Tomcat)

10. Tomcat runs on port 8080 by default. After starting Tomcat, you can see that port 8080 is open.

11. Use the Firefox browser on this machine to test whether Tomcat is running normally. (Tomcat's default port is 8080, so the port should be added during the test)

12. Configure the address and enable the exception of port 8080.

13. In another Tomcat, we will make small changes to the web page to facilitate the test results, and the ip address is configured as 192.168.1.2; The rest of the configuration is the same. Note: In the normal configuration, the configuration of the two Tomcats should be exactly the same. This time, the webpage settings are different to facilitate the test results.

14. Local test.

15. Modify the Nginx configuration file, vim /usr/local/nginx/conf/nginx.conf. First declare the addresses of the two Tomcat servers in the following figure. The weight is the weight. Setting the weight to the same means load balancing.

Add the following line to the position in the figure below, indicating that the default battle of Nginx is proxyed to the set Tomcat load balancing server group through the proxy_pass method.

16. Restart the Nginx service.

17. Configure the address 192.168.1.3 for Nginx and verify. First visit the website on Nginx,

then refresh the page.