Reason analysis of slow loading speed of web page



Analysis Tools:

(1) Mmtrix performance Rubik's Cube: http://www.mmtrix.com/

(2) Firefox YSlow plugin http://www.cnblogs.com/AustinAn/p/3560906.html?utm_source=tuicool&utm_medium=referral

(3) Google Chrome page Speed plugin

：

Http://www.cnblogs.com/AustinAn/p/3560906.html?utm_source=tuicool&utm_medium=referral

Http://blog.sina.com.cn/s/blog_4d834cf30101cbde.html

Http://www.yxxme.com/903.html

The user is slow to open a page because one of the links is out of the question or is not optimized. A brief summary of the reasons for the slow opening of the Web page, mainly has the following points:

First, the network minimum bandwidth

This is the most important factor, that is, netizens often say that broadband is not enough. The same Web site, if the broadband high, access speed will be significantly faster.

The bandwidth of the network includes two aspects of the server bandwidth and the bandwidth of the client, the point of contact is the outlet and the inlet (for example, the joint of Telecom to Netcom).

Second, DNS resolution speed

DNS resolution is the resolution from domain name to IP. People are accustomed to memory domain name, but the machine only recognize each other IP address, domain name and IP address is corresponding, the transformation between them is called Domain name resolution, domain name resolution needs to be specialized domain name resolution server to complete.

DNS resolution includes the number of reciprocating resolutions and the time spent on each resolution, and their product is the total time spent in DNS resolution. Many people ignore the DNS resolution factor, in fact, it is also very important to the speed of the Web site resolution.

Third, server and client hardware configuration

In the same network environment, dual-core server computing power must be stronger. Also in the client, the same network environment, you use a configuration of the Intel® i7 processor and i3 processor to open the same page, the speed must be different.

Four, Server Software

On the server side, the number of software installations and the stability of the operation will affect the server environment, which in turn affects the network speed. For example, a server configuration software firewall can cause network speed to be affected.

Five, page content

If your Web page contains a large number of unprocessed pictures, and these pictures are large, they can cause slow opening. Other such as Flash and video files, will affect the speed of access.

At the same time, redundant code is one of the factors that slow down web site speed. Webmaster needs to optimize the code, with minimal code, to achieve the best results.

VI. Database Operations

Small sites do database operations will also affect the speed of the site, especially at the same time many users submit comments, the operation will occur when the database lock, resulting in the site can not open.

Seven, use javascript effects

The use of JavaScript effects on the site is taboo, not only can not be crawled by the search engine, but also because of the constant request to the server, resulting in the burden of adding servers, the site slowed.

Specific examples such as mouse effects, program effects, status bar effects, and so on. The principle of these effects is first downloaded by the server to the user side of the machine, and then run on the local machine, and eventually be seen by users. Special effects do a lot, users on the local machine on the operation of a half-day ability to complete.

Css,js merge of this merge.

Eight, too much reference to other Web site content

For example, refer to other websites of images, video files and so on. If the link to the site is slow, even if the site does not exist, then the user to open the page will be very slow.

Ix. Back-end issues

The request is too long, the number of requests is too high, a request takes too long (the probability of a few may be: a) resources on the third party site, they are slow; b This resource is too large; c) There is a problem with the domain name used by this resource. ）。

X. Network issues

Take a closer look at a separate HTTP request, which is divided into several stages, namely domain name resolution, connection building, sending request, waiting for response, and receiving data. In theory, domain name resolution and the establishment of a connection should take up a small amount of time, the main time should be used in the later stages. In the illustration above, the light gray and Gray represent the domain name resolution and the connection, which can be seen that the time spent on the network layer is too long for the two requests, more than half of the total time. The network layer time is too long in addition to the underlying network may be related to the site's server-side performance related (back-end rd things OH). Of course, if this happens on a request sent to a third party site (which is often the case), you can advise your sister to cancel or replace certain site features to avoid such a request.

Xi. receiving data over a long period of time

It says that most of the time for HTTP requests should be spent in later stages, such as waiting for responses and receiving data. However, it is also problematic if the data is received for too long, up to hundreds of milliseconds or even in seconds. This is generally because the content of the download is too heavy, such as large pictures, large scripts, and so on. This type of problem can be solved using gzip compression, picture compression, or js/css minify.

12. JS Blocking Request

There's a big gap between the two successive requests in the diagram. May be because of the writing JS performance problems, parse the implementation of JS spent a long time, resulting in this period of time the resource load has been blocked.

He also has a number of factors, such as China's broadband network interoperability problems, the domestic north-South server Exchange will appear delay phenomenon, directly affect the user's Web Access experience. So there are a lot of companies in the choice of site space will try to choose a dual-line or multi-line server.