what is dns cache

The user enters the website address from the browser, to see the complete process of the website:The first step: the user in the browser input https://ke.qq.com/course/28714 website address, carriage return, the system will first query the local DNS

The Yahoo team summarizes the experience of website performance optimization, which is of great reference value.English Original: http://developer.yahoo.com/performance/rules.html1. Minimize the number of HTTP requests 80% of the end-user response

What we call the Web is nothing more than html,css (web font, image), JavaScript.HTML Optimization Recommendations:1. Try not to use table for layout.2. Use the latest semantic H5 tags as much as possible, which is faster when parsing and rendering.3

As a software developer, you will certainly have a complete hierarchical understanding of how Web applications work, as well as the technologies used in these applications: browsers, http,html, Web servers, requirements processing, and so on.This

A: What is HTTP?HTTP is a protocol.Approximate process:HTTP client originating request, creating portHTTP server listens for client requests on portHTTP server returns status and content to clientGhost's Mature Node blog programthe relationship

Steps the browser goes through to visit a websiteChrome searches for its own DNS cacheSearch the DNS cache of the operating system itself (the browser does not find the cache or the cache is invalidated)View the DNS cache information for your Chrome

Url:uniform Resource Location Uniform Resource Locator, as an Internet resource identifier.Ip:internet protocol: A protocol for device communication that specifies a unique IP address for each device.A: Divided into three stagesFirst, address

One of the cache series: buffer, cache, and browser cachingOne: The cache is to adjust the speed of the two or more different velocity inconsistent speed, in the middle of the faster side of a slow speed of access to a party, such as CPU level,

A lot of friends modified the hosts, after the save found not effective, this is why? In fact, there is a DNS cache concept, the general friends are more easily overlooked. Then, the small part of the talk, modify the hosts, how immediately after

Original: http://www.cnblogs.com/yjf512/p/3668877.htmlWhen using chrome, there is a network in the F12 developer tool, where each request has a timeline description, and when the mouse is placed there is the following display:Here are a few

b/S architectureThe most common architectural approach.Advantages:1. The client uses a unified (where the unification mainly refers to the principle of unification) of the browser, do not need a special network configuration.2. The server is based

Original: http://igoro.com/archive/what-really-happens-when-you-navigate-to-a-url/As a software developer, you will certainly have a complete hierarchical understanding of how Web applications work, as well as the technologies used in these

Here are some of the potential factors that affect crawl efficiency (official translation): 1) DNS Settings2 The number of your reptiles, too much or too little3) Bandwidth Limit4 The number of threads per host5 The distribution of URLs to crawl is

DNS Overview: DNS is the domain Name System, which is a distributed database, organized into a domain hierarchy of the structure of the computer and Network service naming system. Its role is: to transform the domain name into a network can identify

When browsing the Web page under the Win7 system, if all the pages are not open, then most of the problem is the network, the problem is that a friend encountered this situation, some Web pages can be opened, and some of the Web page is not open,

This article is the fourth to build SQL Server AlwaysOn from 0, which begins to build a node in an offsite roomNote 1.Note It is best to have at least 2 nodes in the GEO node, or a quorum warning when a manual failover occurs on the local node,

A Linux server Performance View 1.1 CPU Performance View 1, view the number of physical CPUs:cat /proc/cpuinfo |grep "physical id"|sort|uniq|wc -l2. View the number of cores in each physical CPU:cat /proc/cpuinfo |grep "cpu cores"|wc -l3, the number

Solve the Sendmail slow card in Linux-Linux Enterprise Application-Linux server application information. For details, refer to the following section. From: ccvita.com First Ntsysv Directly cancel the sendmail service. This completely solves the

Ten simple methods to mitigate DNS-based DDoS attacks Researchers found that attackers often use UDP flood attacks (UDP floods) in massive bandwidth-based DDoS attacks (Distributed Denial of Service attacks ). Because UDP is a connectionless

Linux hostname and fqdn (FullyQualifiedDomainName) have been confused for a long time. Today, I will use the script home platform to find out their usage details and share them with you the Linux hostname and fqdn (Fully Qualified Domain Name) I