Nginx request limit configuration method

Nginx is a powerful, high-performance web and reverse proxy server with many excellent features:
In the case of high connection concurrency, Nginx is a good alternative to Apache service: Nginx is one of the software platforms often chosen by bosses in the virtual hosting business in the United States. Able to support responses of up to 50,000 concurrent connections, thanks to Nginx for choosing epoll and kqueue as the development model for us.

1. Nginx request limit

limit_conn_module Connection frequency limit
limit_req_module request frequency limit

2. Connection and request of HTTP protocol

1. The concept of HTTP protocol connection and request

HTTP request is based on a TCP connection. To complete an HTTP request, a three-way handshake of TCP is required.
An HTTP request is established based on the TCP connection. One TCP request generates at least one HTTP request.

2. Illustration of HTTP protocol connection and request

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3. The relationship between HTTP protocol connection and request versions

HTTP protocol version	Connection relationship
HTTP1.0	TCP cannot be reused
HTTP1.1	Sequential TCP multiplexing
HTTP2.0	Multiplexing TCP multiplexing

3. Configuration syntax of Nginx connection limit

1. Configuration syntax of limit_conn_zone

Syntax: limit_conn_zone key zone=name:size; limit_conn_zone indicates the requested connection storage space. key indicates which connection is keyed. For example, if the client's IP is used as the key, the restriction is on the client's IP. zone=name indicates the name of the storage space applied for. size indicates the size of the storage space requested
Default: —— indicates that there is no configuration by default
Context: http means that it needs to be configured in the http block

2. Configuration syntax of limit_conn

Syntax: limit_conn zone number; zone indicates the name of the storage space applied for in limit_conn_zone, and number indicates the limit of concurrent requests, that is, the number of connections limited at the same time.
Default: —— indicates that there is no configuration by default
Context: http, server, location means that the configuration needs to be done in the http block, server block, or location block

4. Configuration syntax of Nginx request restriction

1. Configuration syntax of limit_req_zone

Syntax: limit_req_zone key zone=name:size rate=rate; limit_req_zone indicates the requested connection storage space. key indicates which connection is keyed. For example, if the client's IP is used as the key, the restriction is on the client's IP. zone=name indicates the name of the storage space applied for. size indicates the size of the storage space requested. rate indicates the limit of the request, which refers to a limit unit (in seconds)
Default: —— indicates that there is no configuration by default
Context: http means that it needs to be configured in the http block

2. Configuration syntax of limit_req

Syntax: limit_req zone=name [burst = number] [nodelay]; zone=name indicates the name of the storage space requested in limit_req_zone; burst = number indicates that after exceeding the set rate, the remaining number of requests will be put into the next second for execution;
Default: —— indicates that there is no configuration by default
Context: http, server, location means that the configuration needs to be done in the http block, server block, or location block

5. Configuration demonstration of Nginx request restriction

1. First create a submodule.html page and upload it to the /opt/app/html directory, so that you can configure the sub_module module compilation parameters and then access the submodule.html page in the /opt/app/html directory to view the replaced content.

submodule.html page

<html>
	<head>
		<meta charset="utf-8">
		<title>submodule</title>
	</head>
	<body>
		<a>html</a></br>
		<a>xml</a></br>
		<a>json</a></br>
		<a>xml</a></br>
		<a>jsp</a></br>
		<a>html</a>
	</body>
</html>

Browser access is as follows

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2. Edit the nginx.conf configuration file

[root@localhost /]# vim /etc/nginx/nginx.conf

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3. Add the following configuration in the http block

#$binary_remote_addr represents the client's address;
#zone=req_zone indicates the storage space name for requests initiated by the same client address #1r/s indicates once per second limit_req_zone $binary_remote_addr zone=req_zone:1m rate=1r/s;

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4. Add the following configuration to the location block of the http block

#Configuration of nginx connection request limit location / {
    root /opt/app/html;
    limit_req zone=req_zone;
}

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5. Check whether the modified configuration file is correct. If the message "successful" is returned, it means that the configuration file has been modified correctly. Otherwise check the configuration file syntax.

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6. Reload the configuration file

[root@localhost /]# systemctl reload nginx

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7. Use the ab stress testing tool to make concurrent requests

For the installation of ab stress testing tool, please refer to this blog post link: https://wwwxz.blog.csdn.net/article/details/118584751

#-n indicates the number of requests initiated, -c indicates the number of concurrent requests [root@localhost ~]# ab -n 20 -c 10 http://localhost/submodule.html

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This is the end of this article about how to configure nginx request limit. For more information about nginx request limit, please search 123WORDPRESS.COM’s previous articles or continue to browse the following related articles. I hope you will support 123WORDPRESS.COM in the future!

You may also be interested in:

Detailed explanation of Nginx http resource request limit (three methods)
Detailed explanation of nginx request limits (connection limits and request limits)
A brief discussion on the implementation of Nginx request restriction and access control
Global access restriction through nginx proxy interception request
Nginx limits the number of visits and requests to a certain IP in the same time period. Example code
Tutorial on how to configure the module to limit the number of connections and requests in Nginx server

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