Discussion on the number of online users ' consulting server support

The server, as the node of the network, stores and processes 80% of the data and information on the network, so it is also called the soul of the network. To do an image of the analogy: the server is like a post office switch, and computers, notebooks, PDAs, mobile phones, such as fixed or mobile network terminals, such as scattered in the home, all kinds of office space, http://www.aliyun.com/zixun/aggregation/30721.html "> Public places such as telephones." Our daily life with the outside world, the work of telephone exchanges, communication, must pass through the switch to reach the target phone; Similarly, network terminal equipment such as home, the computer in the enterprise Internet access, access to information, communication with the outside world, entertainment, must also go through the server, it can also be said that the server in the "organization" and "leadership" These devices.

It is a network of a variety of services for client computers, high-performance computers, under the control of the network operating system, its connected to the hard disk, tape, printer, modem and a variety of dedicated communications equipment to the network to share the customer site, but also to provide network users with centralized computing, Information Publishing and data management services. Its high performance mainly manifests in the high speed computation ability, the long time reliable operation, the formidable external data throughput ability and so on.

The composition of the server is similar to the computer, there are processors, hard disk, memory, system bus and so on, they are specially formulated for specific network applications, so the server and the computer in the processing capacity, stability, reliability, security, scalability, manageability and so on are very different. In particular, with the progress of information technology, the role of the network more and more obvious, the data processing capacity of their own information systems, security and other requirements are more and more high, if you are in the process of e-commerce by hackers stolen passwords, loss of key business data; If you can't access the ATM You should consider the behind-the-scenes commanders ———— servers in these device systems, rather than blaming staff for their quality and other objective conditions.

Often encounter some do Web user Advisory Server Support Online number problem, here to do a brief introduction. Non-technical discussions, such as omissions or errors, please forgive and guide.

For example, a common single way server, the CPU processing multiple processes, not at the same time processing, (can be accurate to 1/1000 seconds), but serial processing. The CPU usually divides the 1-second time into N, and then in order, the first process is processed in the 1th of 1 seconds, and the second process is processed with the second. With the nth processing of the nth process, that is, CPU processing capacity is not in this second in the number of applications submitted, but in the system to the number of CPU time divided.

For example, the number of default processes in the system can support 256, and the CPU will be 1 seconds into 100, then the remaining 156 processes will be executed in the next second, the network card will be requested to enter the memory queue after the message, so usually large memory, you can feel the support of the number of online more In essence, the CPU is related to the time slice, the higher the performance of the CPU partition of the time slice may be more, that is, processing speed quickly.

Of course, a process here is not just a request, a process can usually contain 100 identical requests, so that the CPU can handle the number of requests in 1 seconds for 100*100=10000, however, we know that most users can not only submit a request in a minute, that is, just click on a link.

In addition, bandwidth is the most important factor to support the number of online people, the server according to our guaranteed maximum bandwidth is 5M, that is, 5mbit/s, the server's highest data transmission speed should be 5/8byte/s*1024=640k/s. One minute traffic is about 640k/s*60=38400k, if each user occupies 10K in one minute, that is, 3840 people are supported online in that minute. (Pictures and video class sites are not in this case, because the picture class video class each user in a minute is absolutely more than 10K), but we do not guarantee that each user only accesses one station link in a minute, if each user points the station two links in a minute, then the support online number should be below 2000.