[performance tuning basics] performance tuning standards

When do I start to get involved in tuning ？

After system coding 、 After the project is successfully launched

Which computer resources will become the performance bottleneck of the system ？

CPU、 Memory 、 disk I/O、 The Internet 、 abnormal 、 database 、 Lock competition

What indicators can be used as the criteria for performance tuning ？

response time 、 throughput 、 Computer resource allocation utilization 、 Load carrying capacity