Basic Concepts---performance testing

• Performance test: In a certain load situation, the system's response time and other characteristics to meet the specific performance requirements.
• Load test: By testing the performance of the system in case of resource overload, to discover design errors or to verify the load capacity of the system.
• Stress test: Refers to the system's operation under the condition that the measured system is saturated with a certain amount of resources (CPU, memory).
• Reliability testing: The operating condition of the system under test for a long time operation.
• Configuration testing: By adjusting the different configurations of the tested system hardware and software, we find a configuration that is most suitable for the system under test or the operation of the tested system under different configurations.

1. Concurrency and parallelism

• Concurrency: in the operating system, there are several programs in a period of time that are running from the start to completion, and these programs are running on the same processor, but only one program is running on the processor at any one time point.
• parallelism: When the system has more than one CPU, the operation of the thread may be non-concurrent. When one CPU executes a thread, another CPU can execute another thread, and two threads do not preempt CPU resources, which can be done simultaneously, which we call parallel (Parallel).

2. Number of concurrent users and online users

• Concurrent Users : The number of users who submitted requests to the system at a physical time
• number of users online: the number of users accessing the system during a certain period of time, and these users do not necessarily submit requests to the system

3. TPS (Transactions Per Second) and response time

TPS: Number of transactions per second

Response time: The time at which a customer makes a request to a response, response time = client + server side + Network

4, clicks (The number of clicks is not the number of mouse clicks)

The number of HTTP requests that the user submits to the Web server per second. This indicator is a unique indicator of Web application: The Web application is a "request-response" mode, the user makes one request, the server will process it, So click is the smallest unit of transactions that the Web app can handle. If you define each click as a trade, CTR and TPS are a concept. It is easy to see that the larger the CTR, the greater the pressure on the server. CTR is just a performance reference, and it's important to analyze the impact of clicks. Note that the Click here does not refer to a single click of the mouse, because in a single click, the client may make multiple HTTP requests to the server.

5. Throughput: The number of business or requests processed by the system under measurement per unit of time

6. Utilization rate of resources

7, PV and UV

• PV: Access to a URL, resulting in a PV (page View, the number of pages visited), the daily Total PV volume per site is an important indicator of the size of a website.
• UV: As a standalone user, all pages that visit the site count as a single UV (Unique Visitor, user access).

Basic Concepts---performance testing