foreword

In the process of testing a job-level application, it is inevitable to test some performance of the service, such as the amount of cpu usage, the size of the memory used, etc. The simpler way is to create a parallel thread in the service, each Print the size of these concerns every once in a while, and then sort the printed values in chronological order, and draw a picture to see the rules

Here to calculate these quantities, there is a library in python that is psutil

psutil

Install

pip install can

pip install psutil

doc：https://psutil.readthedocs.io/en/latest/#

Introduction to common methods

1. cpu_percent

doc：https://psutil.readthedocs.io/en/latest/#psutil.cpu_percent

cpu usage, the return is a number from 0-100, the unit is %

interval: seconds percpu: True/False True for each cpu, False for total cpu

Pay special attention here when the interval is 0, the first call returns 0

print(psutil.cpu_percent(interval=30))
print(psutil.cpu_percent(interval=10, percpu=True))

result:

8.3

[31.2, 0.8, 27.0, 0.7, 22.2, 0.8, 18.9, 0.8, 16.8, 0.8, 13.5, 0.9]

There are 12 cpus shown here, if it is a mac, execute

sysctl machdep.cpu

You can see the information of the cpu

# 总核数 = 物理CPU个数 X 每颗物理CPU的核数
# 总逻辑CPU数 = 物理CPU个数 X 每颗物理CPU的核数 X 超线程数
core_count： 物理cpu的核数
thread_count： 逻辑cpu的数量

psutil.cpu_count

print(psutil.cpu_count(logical=False))  #6
print(psutil.cpu_count(logical=True))  #12

The default logical is True, returns the number of logical cpus, if it is False, returns the number of physical cores

The official website writes more clearly:

Return the number of logical CPUs in the system (same as os.cpu_count in Python 3.4). “logical CPUs” means the number of physical cores multiplied by the number of threads that can run on each core (this is known as Hyper Threading). If logical is False return the number of physical cores only.

3. psutil.virtual_memory

returns many values

s = psutil.virtual_memory()
print(s)

This command is similar to the free command in linux: https://blog.csdn.net/lijinzhou2017/article/details/103008827

total The total available physical memory size of the system
available The physical memory size that can also be used by the application
used The physical memory size that has been used
free How much physical memory is available
percent (total-available)/total

The units are all bytes, so if you want to display G when displaying, you need to divide by units = 1024✖️1024✖️1024

If you just want to know how much physical memory is left in a cross-platform way, just rely on available and percent

reference

https://www.cnblogs.com/feibazhf/p/12858792.html

psutil for system monitoring and process management python library