1、目前正在研究jmeter，請問初期做性能，應先從幾點做起？
Jmeter和LR都是目前效能測試的首選工具，如果你有LR的學習背景，那麼Jmeter上手會很快，重點理解執行緒和進程的概念，流程和LR是類似的。如果沒有，從入門的角度我建議先了解常用網路協定和作業系統執行緒和進程的概念，Jmeter用java比較理想，可以考慮了解一些程式設計基礎。 PS:其實用Jmeter先學習介面測試會更好理解效能。
2、請問零基礎，電腦硬體專職業轉行到這個產業，需要準備哪些？
電腦硬體已經具備了基礎的電腦知識，要轉軟體是相對容易的，可以考慮從以下維度準備：
1)先準備自己拿手的網路和作業系統部分，網路主要是應用層協議，為效能和介面測試做鋪墊，作業系統主要是為了搭建測試環境
2)建議熟悉一種程式語言，java或Python都是首選語言，不需要精通，至少要能夠進行簡單的腳本編寫
3)找一本介紹全面的專業的軟體測試書籍精讀，一定是精讀。
4)如果可能最好找專案練手，從功能測試開始
3、目前做介面測試，進階的時候還是會茫然，希望您能給點建議，另外您在做管理的時候，對員工一般是持什麼態度，或者說姿態呢？如何培養，如何相處，如何分配任務，控制專案進度，品質？
這問題好大，我挑些重點說:
1)介面測試其實是協定的測試，建議你從網路協定入手，這樣才能做好介面測試
2)至於測試管理工作我認為因人而異，有些人天生強勢，但有些偏平和，最關鍵的還是自身實力，如果自己不夠強，一句俗話叫做將熊熊一窩就是這個理，姿態不重要，實體才重要。
3)至於培養，相處，分配任務這些是管理細則，總的思路是用其所長補其所短，人無完人，而且大多數都會覺得自己比領導牛B，讓每位員工發揮最大價值，有成就感比較重要。
4)控制專案進度和品質 這個是方法問題，有很多方法可以控制，例如：測試版本控制，缺陷分析等手段，可以參考軟體工程，敏捷流程等方面的資料。希望對你有幫助
4、用Loadrunner做壓測，反應時間比實際高很多，用LR做壓測，平均反應時間幾十秒鐘，實際手動開啟連結1秒不到，差距很大，請問有哪些原因會導致這個問題呢？
例如下圖，vuser才十幾個，回應時間就十幾秒了，但實際上的體驗還是很快，如何解決？
初步猜測應該是回應時間的設定不當導致的，舉例說明：你要錄製登入腳本，並記錄登入的回應時間，你在LR的腳本中插入了事務函數（注意是一組函數），結果得到的回應時間是5s，但實際登入你感覺不到1s，那麼可能是你的函數位置不對，包含了輸入使用者名稱和密碼的時間，也可能是你的回應時間函數內包含了思考時間。你需要調整前者事務的位置，或在後者運行時設定中排除思考時間。供參考
5、請教一下怎麼樣去抓程式的頁面元素啊？像Selenium web那樣 抓頁面的元素？有什麼好的工具或方法？
建議使用Chrome開發者工具的Elements選項查看，以抓取頁面元素。除了使用Selenium，也可以考慮使用QTP（ALM）來進行自動化測試
6、請問軟體疲勞測試該怎麼做？
一般是做壓力測試，壓測依據項目和業務的不同都會有所差異，建議三種，一種是4H峰值壓力的80% ；一種是24H，壓力量可以控制在60p %，還有一種是7*24小時（有的是一直持續50%的壓力，有的是按時間波動壓力值進行測試）
#7、對B/S系統做壓力測試前需要做哪些準備？如何客觀的去分析一個系統？壓力測試工具以前只接觸過 Loadrunner，所以打算用Loadrunner，不太熟，裡面的需要做的系統指標的設定看起來很麻煩，不知怎麼去分析系統。除了選擇熟悉的工具，做壓力測試前還需要做什麼準備工作？
你的問題很難一兩句話說清楚，對於前期準備工作，只能談談我在性能測試項目中的拙見：
1）先對需求進行初步分析，確定哪些環節需要效能測試，也就是對你們系統來說壓力最大的點在哪裡
2）看現有資源，提前做好環境的準備工作，最好測試環境和生產環境1： 1（實在做不到也要盡量接近，這點很重要，不然你要做等比換算）
3）看被測系統使用的協定以及作業系統和應用伺服器等各類配置，選擇匹配的測試工具（多數WEB系統LR是可以應付的）
4) Look at the time. In most cases, there is not enough time for performance testing, so you need to focus on testing first.
8. How to choose between Loadrunner and Jmeter?
It all depends on your mood, just kidding~~ If you look at the code and network basics from the perspective of learning and getting started, if the code and network basics are good, just use Jmeter to get started, otherwise it is better to use LR to get started. From the perspective of enterprise applications, which one is more suitable and has better support for the system under test?
Tools are just forms. You can use any tool to understand the basic principles of performance testing.
9. How to locate the problem of frequent GC in Java?
Please try to use profiler to find memory abnormalities, such as too many objects created in a short period of time, or large object creation.
10. I want to implement 50 users to clock in and clock in concurrently. Parameterization and iteration have been set up. Then, I added a rendezvous point function in front of the sign-in function. The running results found that the sign-in time returned after the user signs in is One per minute, not checking in at the same time! Please tell me why? How to solve it?
How about removing the meeting point first? Start 50 users in parallel at the same time (concurrent operations can be achieved without setting a rendezvous point). If it still lasts for one minute, please check the transaction time and thinking time. The transaction time needs to be manually configured by you. The thinking time is in the startup state by default. , you can check it in the Runtime Setting. It is possible that the 1 minute you finally get is the time for the entire script to run once or the result includes thinking time, not the time to clock in at the same time.
11. How are e-commerce flash sale products tested?
It is not much different from the testing of other products. The main reason is that the time point requirements are relatively high. You can consider using the rendezvous point function in the performance test script to achieve concurrency in the same second.
12. Are stress testing and performance testing the same?
The classification methods are different and there is no conclusion. Generally speaking, performance testing is a general term for this type of testing. I prefer the following classification method
Performance testing (narrow sense) - The performance testing method is to test whether the performance of the system meets the requirements of a specific operating environment by simulating the business pressure of production operations and the combination of usage scenarios. production performance requirements.
Benchmark testing - simulate a certain number of users running one or more services under certain software, hardware and network environments, and use the test results as baseline data for reference in subsequent testing activities.
Load testing - by continuously increasing pressure on the system under test until the performance indicators reach the limit, such as "response time" exceeding the predetermined indicator or a certain resource has reached saturation.
Stress test - Stress test is also called strength test. It mainly tests the session capacity that the system can handle under a certain saturated state, such as when the CPU and memory are saturated, and whether errors will occur in the system. . Note: Keep running for 2-4 hours at the limit value of about 80%.
Configuration test - Configuration test method Through the adjustment of the software and hardware environment of the system under test, understand the various effects on the system The degree of performance impact, so as to find the optimal allocation principle of various system resources.
Reliability test - when the system is loaded with a certain business pressure, run the system for a period of time to detect whether the system is stable.
Concurrency testing - The concurrency testing method simulates concurrent user access to test whether there are deadlocks or other performance issues when multiple users concurrently access the same application, the same module or data records.
PS: Classification is actually not that important. In actual projects, they are often mixed applications
13. In addition to concurrent login, what are the other common test scenarios for web performance testing?
The scenario depends on the business. For example, if you are an e-commerce website, you must test the situation of placing orders at the same time? ?; if you are a hospital registration website, you must test that multiple people compete for a doctor's number source; If you are a banking system, you should consider multiple people withdrawing money at the same time, right?
14. How much pressure does a typical website have on millions of users?
This depends on the calculation method. The theoretical value of 1 million/day business visits divided into every second is very small; but this is not in line with the actual situation.
Based on online data, we can directly calculate the number of peak periods every day and the corresponding number of concurrent users
If the system is not online, you can use the 2/8 principle, and 80% of users are concentrated in 20% of the time period, the number of business visits is deduced
15. I am currently encountering a problem. When running a stress test on a win7 system configured with 8g and i3, the concurrency always fails to increase and is always at 140. Abnormalities, timeouts and other problems will appear around the time. How to analyze it? Is it because of the server or the computer problem?
If the server pressure does not increase, you can analyze it from the following dimensions:
Whether there are restrictions on network traffic,
Whether the database/application server reports an exception, if so, please check the log ;
Check the resource monitoring status of the operating system, how the CPU usage is, and whether it has reached 100%
If there are any performance problems in the code, you can manually access the system during large concurrent access. See Check whether there are any abnormalities in the business.
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