Shulou(Shulou.com)06/03 Report--

The following content comes from the works of the trainees of Xiaoqiang Test Brand training course.

Phenomenon

Because the company needs to stress test the system, it uses LR to stress test the registration business of the website. When the concurrency is 7, there are a large number of errors:

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Analysis and solution

First of all, solve the 27796 errors that occur most, in the attempt to modify the registry

Two key values for HKEY_LOCAL_MACHINE\ SYSTEM\ CurrentControlSet\ Services\ Tcpip\ Parameters:

TcpTimedWaitDelay-1 MaxUserPort-65534; reduce the port wait time, increase the maximum available port, and run MaxUserPort again without reporting a 27796 error

Xiao Qiang's comments:

Many friends are confused when they encounter mistakes and have no idea what to do. There are hundreds of thousands of reasons. And I have always stressed that we are not afraid of mistakes or even 100 mistakes. Our simplest principle is to solve the one with great influence.

Secondly, for a large number of 503 error reports, first check the system error log, the log is shown as: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure, then think of what Xiaoqiang teacher said in class, just like this, so adjust the parameters related to timeout. When the scenario is run again after restarting mysql, there are still a large number of 503 errors, and the same error is reported when looking up the system log.

Xiao Qiang's comments:

This type of error has been mentioned in class, and this student has a good association with it and tries to solve it. Knowledge doesn't care how much, but whether it is systematized or not. You learn a lot of things but you don't have a systematic structure. The adjustment here does not have a very good effect. At this time, many friends will have a hundred thousand why, in fact, it is not necessary. This is the fun part of performance testing. You need to analyze it slowly, and you can do it in a minute.

I really have no idea. After asking teacher Xiaoqiang, I changed the configuration of tomcat and added parameters to the configuration file:

After minEvictableIdleTimeMillis, numTestsPerEvictionRun, testOnBorrow, etc., and try to adjust the settings

No longer report link failure error

Xiao Qiang's comments:

Many people will not analyze multiple problems, even if they will, after analyzing one, they will not be able to solve them and then give up. There are ways to do everything, and we attach too much importance to technology to the neglect of methods and thinking, which is one of the reasons why only a few people can do complex work. And here I am also based on hierarchical thinking to provide guidance, specifically or this student understand and solve, must like! I have always thought that teaching people not only to teach skills, but also to teach the way of thinking to do this thing, this is valuable.

While happy, not long, accidentally saw such an error in nginx: limiting connections by zone "addr", client:., here understand that the same ip is restricted link, open the nginx configuration found that there is indeed a limit parameter: limit_conn_zone $limit zone=addr:1m This parameter restricts the same IP to make multiple requests to the system, but the press is a single machine, so it is sure to report an error. You can comment out all of this during the stress test. The more important point is that you should not only comment out this configuration, but also restart nginx after commenting out all the limit configurations related to this configuration in the server area.

Running LR no longer reports 503 errors; under high concurrency, the transaction pass rate is also 100%. Those are the tears I was moved to.

Xiao Qiang's comments:

Through the guidance to learn to use key information for investigation and analysis, very good, and can learn a hundred, great progress, like again. Most of the time, the teacher is acting as a guide, not an omnipotent god, and more often depends on everyone's own spiritual practice.

After that, a problem was found in the pressure test.

Com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException probably had a chat with the developer. It should be that the registration business involves a lot of tables, and there may be foreign keys set in the table. After the development investigation, the problem has been solved, and now it is basically very stable.

Xiao Qiang's comments:

It is not ashamed to ask the most stupid chicken soup, how many people have lost the ability to think and solve problems on their own initiative? I think everyone knows that. When you encounter a problem, you should learn to think for yourself and try, and then you can discuss it with your thoughts. In addition, now is teamwork, everyone has their own good, will not be serious, ask the people to help in learning, do not be too rigid. Here the trainee finds the problem and solves it after consultation with the developer. Very good! Being good at collaboration is a necessary skill and the most important skill for every test engineer!

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