Study Note 5: The instantaneous response of the core principle and case analysis of large web site technology architecture: high-performance architecture of the website

Website Performance testing is the premise and foundation of performance optimization, and is also the inspection and measurement standard of performance optimization results.

Different people will have different metrics: users, developers, ops people.

First, performance test indicators

1. Response Time

Refers to the time it takes an app to perform an action, including when the request starts and the last response data is received. Response time is the most important performance index of the system, which reflects the ' speed ' of the system intuitively.

2, concurrent number

The system can process the number of requests at the same time, this number reflects the load characteristics of the system, for the Web site, concurrency is the number of concurrent users of the site, refers to the number of simultaneous users to submit requests.

Site system users number of online users website number of concurrent users

At the beginning of the site design, product managers and operators will need to plan the number of site system users at different stages of development, based on the product characteristics and operational means, the number of online users and concurrent users.

These indicators will become an important basis for system non-functional design.

3. Throughput

Refers to the number of requests processed by the system within a unit of time, reflecting the overall processing capacity of the system.

• TPS: Number of transactions per second
• HPS: Number of HTTP requests per second
• QPS: Number of queries per second

Response time, concurrency number, throughput, three can be described by the highway. The response time is the speed, the concurrent volume is the car that is driving, the throughput is today through the toll station of the number of cars.

4. Performance counter

Some metrics that describe the performance of a server or operating system, such as system load, number of objects and threads, memory, CPU, disk, network IO, etc.

• System load: The sum of the number of threads that the current CPU is executing and waiting for the CPU to perform is an important indicator of how busy the system is.

Second, the performance test method

1. Performance test

Based on the performance index of the initial planning of the system design, the system continuously exerts pressure to verify whether the system can achieve the performance expectation within the acceptable range of resources.

2. Load test

On the basis of the performance test, the system continues to increase concurrent requests until one or more of the system's performance metrics reach a security threshold until the processing power decreases.

3. Pressure test

Continue to exert pressure on the system in excess of the security load until the system crashes or stops the service to obtain the maximum pressure withstand range of the system.

4. Stability Test

Tested system in a certain hardware, network, software environment, to the system load a certain business pressure, is the system to run a long time, in order to detect whether the system is stable.

Study Note 5: The instantaneous response of the core principle and case analysis of large web site technology architecture: high-performance architecture of the website