Cause Analysis of user disconnection Problems

Cause Analysis of user disconnection Problems

Wu Yu

Taiyan Network Studio

 

Rarely participate in weekly third-party meetings. Yesterday, I had to explain a complaint and listened to the complaint for half time. Among them, the most controversial is also the most serious problem of recent complaints, that is, the user disconnection problem.

There are many C/S architecture products on the market, and there are various causes of disconnection problems. Based on my previous experience in developing Intranet security products and network communication, the reasons for disconnection problems are roughly divided into the following categories:

1. server or client bugs

This type of problem is generally better solved. The pure code problem is always easily solved through debugging. The more mature the product, the less problems it will be. Of course, it is difficult to find bugs that are hidden deeply. However, most cases can be solved through simulation. For example, if there may be a problem with the server, write a simple server program, and simply simulate several protocols in the login process to find out the cause of the problem.

Ii. network hardware problems

This type of problem is sometimes difficult to troubleshoot because there are many nodes in the network. For example, if a vswitch breaks down or a network cable is not plugged in, it may cause intermittent interruption. This type of problem is characterized by universality. When a problem occurs, everyone has a problem, or a software problem, other software also has a problem.

Iii. Firewall Problems

When it comes to firewalls, it becomes very difficult. There are many types of firewalls on the market, and they are increasingly inclined to "active defense", so even if you do not do anything "bad ", it's hard to keep it as "Suspect" that you may be able to filter you out by doing bad things. The firewall's policies are mostly "Suggestion of guilt". If you suspect that you have a problem, you have a problem.

Iv. Adaptability

This is a very serious thing that software developers often ignore! After entering China for so many years, KFC is still seeking for localized business strategies, such as providing lunch with rice. In the United States, it is very successful to provide only hamburgers. In China, it is necessary to consider the importance of rice in Chinese eating habits.

We choose to deploy multiple data centers in different locations during data center deployment. This is a localization strategy that allows users to connect nearby to Ensure network stability and avoid various problems caused by cross-network deployment. However, the communication protocols in our C/S architecture generally have only one set of features. That is to say, these communication packet workers may pass through the 99% network firewall normally, but they cannot guarantee that the firewalls of all products will not filter out your packets.

Once upon a time, some companies disabled im Instant Messaging Tools. Later, Im companies provided online versions, because most companies did not disable HTTP. This problem was solved as a result.

Similarly, our communication protocols can also be diverse. For example, there are completely binary, HTTP-like, ftp-like, and POP3/SMTP protocols. The following protocols are public protocols. All Network firewalls are usually allowed.

Binary protocol, we can also have a variety of looks. It's hard to secure a certain data packet. It looks like a virus code, but if we can encapsulate it into several different data packets, it would be much easier. This kind of long-looking data packet is filtered out, and we can also use other long-looking data packets.

I think our solutions to problems can be broader and more flexible. However, the premise is to understand the root cause of the problem and the essence of the matter. It is easy for us to fall into the following scenarios to solve the problem.

 

Programmer:There is no problem with our code. It is a network problem.

O & M personnel:I can't solve the broadband firewall problem in a certain residential area, and people will ignore us.

Leaders:Is this my problem?