Nginx Service Quick Start Tutorial

1. Introduction to Nginx

1. What is Nginx?

• Nginx (engine x) is a high-performance HTTP and reverse proxy web server that also provides IMAP/POP3/SMTP services.
• Its characteristics are that it occupies less memory and has strong concurrency capabilities. In fact, nginx's concurrency capabilities perform better among web servers of the same type.

2. Why use Nginx?

With the rapid development of the Internet today, single-point servers have long been unable to support the continuous access of tens of thousands or even hundreds of thousands of users. For example, a Tomcat server can only handle about 2,000 concurrent requests under ideal conditions. To solve this problem, multiple Tomcat servers are needed for load balancing.

So, how should load balancing be achieved? Nginx is one of the solutions. When a user visits a website, Nginx intercepts the access request and distributes it evenly to different servers through polling.

In addition, there is an ip_hash strategy in Nginx, which can obtain the user's real IP and calculate the hash value to select the server. This is also an excellent load balancing method. Therefore, mastering Nginx has become an indispensable part of the Web development learning journey.

3. What is a forward proxy?

Forward proxy means that the client sends its request to the proxy server first, and then the proxy server forwards the request to the server. The VPN we commonly use is a proxy server. In order to connect to foreign websites, the client needs to use a server that can connect to the external network as a proxy, and the client can connect to the proxy server.

4. What is a reverse proxy?

A reverse proxy is different from a forward proxy. A forward proxy acts as a proxy for the client, while a reverse proxy acts as a proxy for the server. When there are multiple servers distributed, in order to allow the client to access the same website through the IP address, a reverse proxy is needed.

After understanding the working mechanism of reverse proxy, you can start learning Nginx!

2. Installation of Nginx under Linux

Since Nginx is widely used in Web servers, this tutorial chooses version 7.4 of the Centos server as a demonstration!

1. Download

Go to the official download page: http://nginx.org/en/download.html, select the Stable version to download, and upload it to the server.

2. Installation

After uploading the tar package to the server, decompress it to the current directory

tar -zxvf nginx-1.18.0.tar.gz -C ./

Enter the unzipped directory and execute the configure script

cd nginx-1.18.0/
./configure

Install using the make command

make && make install

After the installation is complete, use the whereis command to find the installation location of Nginx (installed in the /user/local/ directory by default)

whereis nginx

Enter the bin folder under the installation directory, start the nginx service, and access the server's default port 80 to check whether the installation is successful!

3. Getting Started with Nginx Configuration

1. Configuration File

There is a conf folder in the Nginx installation directory. Open the nginx.conf file in it.

cd conf/ && vim nginx.conf 

2. Reverse proxy for a single server

So, how to use Nginx for reverse proxy?

Add the proxy_pass field in the location parameter and fill in the server address and port number that require reverse proxy:

Note: Each line of configuration needs to end with a title! ! !

#Configure the listening directory to be: /
location / {
	root html;
	index index.html index.htm;
	proxy_pass http://127.0.0.1:8080; # Reverse proxy for port 8080 of the local machine # proxy_pass http://127.0.0.1:8081; # You can configure multiple proxy_pass at the same time, reverse proxy for port 8081 of the local machine}

3. Reverse proxy multiple servers

What if there are multiple servers? In addition to constantly adding proxy_pass parameters, a better solution is to configure the upstream server group!

Add the upstream attribute to the http block of the configuration file:

# Configure a server group named hello
upstream hello{
	# One server corresponds to one server, of course it can also be a web program with different ports server 127.0.0.1:8080;
	server 127.0.0.1:8081;
}
# Modify the reverse proxy in the location block to server group location / {
	root html;
	index index.html index.htm;
	proxy_pass http://hello; # reverse proxy all servers in the hello server group}

4. Run the test

1. Start the service

After the configuration is complete, enter the sbin folder under the Nginx installation directory and run the nginx program:

/usr/local/nginx/sbin/nginx

If it has been started before, there is no need to shut down the nginx service, just let nginx reload the configuration file:

nginx -s reload

Refresh the browser. If the reverse proxy is successful, the accessed path will be automatically mapped to the server address in the configuration file!

In the future, as the number of users grows, you may need to add new servers; at this time, you only need to modify the configuration file and use the nginx -s reload command without shutting down the nginx server!

2. Shut down the service

There are generally two ways to shut down the nginx service:

nginx -s stop # Stop immediately, whether it is working or not nginx -s quit # Wait for the process to complete the current work and then exit safely

5. Load Balancing

1. What is load balancing?

Since different servers have different configurations, the concept of load balancing was introduced to allow high-performance servers to be allocated more requests.

As mentioned earlier, Nginx can have many load balancing methods, such as weighted round-robin (default), IP hash, url hash, etc. Here we will introduce weighted round-robin.

Weighted round-robin means that by adding weight values ​​to the servers, Nginx distributes requests based on the weights. The higher the weight, the more requests it receives, and vice versa:

The above figure configures three servers. In the weighted polling mode, among 6 different requests, the server with a weight of 3 will be allocated 3 requests, the server with a weight of 2 will be allocated 2 requests, and the server with a weight of 1 will be allocated 1 request. Load balancing greatly reduces the risk of server downtime in a high-concurrency environment!

2. Configure Nginx load balancing

Similarly, open the nginx.conf file to configure:

vim nginx.conf

Add the weight parameter in the upstream block:

upstream hello{
	server server1:8080 weight=3; # Configure the weight of server1 to 3
	server server2:8080 weight=1; # Configure the weight of server2 to 1
}

After adding, execute nginx -s reload!

The above is the detailed content of the Nginx service quick start tutorial. For more information about the nginx introductory tutorial, please pay attention to other related articles on 123WORDPRESS.COM!