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How to improve the access speed of PHP website through DNS pre-resolution?
- 王林Original
- 2023-08-06 12:01:051392browse
How to improve the access speed of PHP website through DNS pre-resolution?
In actual website development, access speed is a very important indicator. DNS (Domain Name System) pre-resolution is an effective method that can improve website access speed. This article will introduce how to improve the access speed of PHP websites through DNS pre-resolution and provide corresponding code examples.
1. What is DNS pre-resolution?
DNS pre-resolution refers to resolving the IP address corresponding to the domain name of the website in advance before the user accesses the website. Normally, users will first access the domain name of the website, and then the DNS server will resolve the domain name into an IP address, and then the user can access the website normally. The function of DNS pre-resolution is to resolve the domain name into an IP address in advance, so that when the user accesses the website, the IP address can be used directly to access the website without the need for DNS resolution, thus improving the access speed.
2. How to implement DNS pre-resolution?
- Use PHP’s gethostbyname() function to perform DNS pre-resolution.
The gethostbyname() function is used to obtain the IP address corresponding to a domain name. We can add the following code to the home page file of the website to perform DNS pre-resolution on the domain name of the website:
$domain = "www.example.com"; // 网站的域名 gethostbyname($domain); // 进行DNS预解析
- Use the link tag of HTML to implement DNS pre-resolution.
HTML link tag can be used to preload related resources, including DNS pre-resolution. We can add the following code in the 93f0f5c25f18dab9d176bd4f6de5d30e tag of the website to perform DNS pre-resolution on the domain name of the website:
<head>
<!-- 对网站的域名进行DNS预解析 -->
<link rel="dns-prefetch" href="//www.example.com">
</head>3. Precautions for DNS pre-resolution
- DNS pre-resolution The parsing is only valid for users who visit the website for the first time. This is because after the first visit, the user's browser will cache the IP address of the website, and the cached IP address can be used directly during the next visit without the need for DNS resolution.
- DNS pre-resolution may cause additional network load. Because DNS pre-resolution will perform domain name resolution in advance, it may cause additional load on the DNS server.
- DNS pre-resolution requires server support. Although DNS pre-resolution is implemented through the client (user's browser), the server also needs to provide corresponding support. Specifically, the server needs to have the ability to quickly respond to DNS resolution requests.
- DNS retry time may affect the effect of DNS pre-resolution. DNS retry time refers to the time interval between retrying DNS resolution when the user's browser fails. If the DNS retry time is long, the effect of DNS pre-resolution may be weakened.
4. Summary
DNS pre-resolution can reduce the time of DNS resolution, thereby improving the access speed of PHP websites. In actual development, we can use PHP's gethostbyname() function or HTML's link tag to perform DNS pre-resolution. However, it should be noted that DNS pre-resolution is only effective for users who visit the website for the first time and requires server support. When applying DNS pre-resolution, you also need to consider the impact of DNS retry time on the pre-resolution effect.
I hope this article will help you understand how to improve the access speed of PHP websites through DNS pre-resolution!
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