What is the number of IIS connections?

The number of IIS connections is the number of accesses that the server can accept at the same time, and can be easily understood as the number of threads that are allowed to send a read to the server at the same time.

We are divided into 5 kinds of circumstances to introduce to you: (100M space to limit 50IIS as an example)

1, users single-threaded or multi-threaded download your site files, after the normal disconnect, these connections are calculated in an instant, that is 50IIS of space can be accepted at the same time a maximum of 50 threads to download.

Note: At present some multithreading tools such as thunder, Internet Express BT version, can also perform 80 thread download, so even if only one user is downloading your site files, the site is also open.

2, when a Web page is browsed, the server and the browser to create a link, each link represents a concurrency. When the page contains a lot of pictures, the picture is not a single display, the server will produce multiple links at the same time send text and pictures to improve browsing speed. The more pictures on the page, the more concurrent links the server has. When a picture or page is sent by a service, the server closes the link to create a link with the other requester.

Note: Some users say that opening 1 Browse Windows is the number of 1 IIS connections turned on. So theoretically 50 IIS space can accommodate 50 people at the same time online, this argument and reasoning is wrong. If you open a page and there are two pictures in the page, when you open the page, The number of IIS threads required is 3 (1 for the HTML code to read the page, and 1 for both pictures).

3, the user opens your page, even if stays on the page does not make any request to the server, then in the user opens one side after 15 minutes also to calculate an on-line, namely 50IIS website can accept different user to open 50 pages in 15 minutes

Note: Also some users also proposed 50IIS host why the counter shows the number of online 5 people can not open, the truth is the same. The number of online users in accordance with the user's last click (Request) 15 minutes after the calculation, in this 15 minutes regardless of how users click (including a new window to open) counters are calculated according to one person online, and IIS number is not the case. The correct explanation should be: access to your site has 50 connections, of which the normal access to the forum of 5 people. Obviously the number of online people is different from the number of IIS connections.

4, when your page exists within the framework (IFRAME), then each more than one frame will be more than one times the online! Because this is equivalent to a user requesting multiple pages at the same time to the server.

5, some users of the ASP page calls too many pages, some to 10 several, this is also a serious cost of IIS.

6, when the user opens the page and then closes the browser normally, the number of users online will also be cleared immediately.

What does it mean to limit the number of CPUs allocated?

Dual Xeon 2.8 processor, that is, a limit of 8 CPU host, its data processing capacity has been quite strong (a few years ago a P3 server is also running dozens of stations), when your station program in the implementation of the CPU required more than the limit, resulting in thread congestion, the server can not send data, IIS will restart your site separately, and the process will last for about 30 seconds, and the site will not be accessible at this time.

Some users suggest how many IIS connections can the 8 CPU limit actually support?

Based on our engineers ' experience online numbers need to see your program situation,

1, the HTML site at the same time the number of people will not be overrun, because the HTML is not explained through the server, but through the client's browser to explain that our hosts are 100M exclusive, so there is no problem with the bandwidth of the implementation of HTML is not limited.

2, the difference between the ASP program is very large, if 8 of the CPU limit the number of IIS, under normal circumstances, there is no dead loop, deadlock program is probably in 800-5000.

3, other PHP, CGI, NET, and other programs will be more efficient execution than ASP file 2-3 times.