In Java programs, most of the causes of performance problems are not the Java language, but the program itself. It is very important to develop good coding habits, which can significantly improve program performance.

The steps of performance tuning mainly include: measuring the current situation of the system, setting tuning goals, finding performance bottlenecks, performance tuning, and verifying whether the tuning goals are achieved.

Java performance tuning in modern large-scale critical systems is a challenging task. You need to pay attention to various issues, including algorithm structure, memory allocation mode, and the use of disk and file I0. The most difficult part of performance tuning is to find out the problem. Even experienced people will be misled by their intuition. The performance killer is always hidden in the most unexpected places.

To optimize the performance of Java programs, not only must have a sufficient understanding of the application code implementation, but also a deeper understanding of the lower-level OS and JVM. This article combines a lot of knowledge at the OS. JVM level that Java programmers also need to master: What is more attractive is that combined with their own experience, I summarized some performance optimization modes for everyone, such as how to optimize when the CPU utilization is high. , These modes have benefited a lot, and I believe that after reading them, they can provide a lot of help for performance optimization in your daily work.

So your editor (Lei Feng) did not spare this week to organize this information about Java performance actual combat source code + notes + project combat. This document is a bible for Java application performance tuning. The content is easy to understand. It introduces a large number of monitoring and measurement tools, involving various hardware architectures and operating systems. It covers techniques such as how to structure experiments, interpret results, and how to take actions. If you are a detailed control, then this book is for you.

The above is the content contained in the material. The following editor will show the catalog and detailed screenshots. Those who need complete source code + notes + actual project combat, only like the article, and then get the method at the end of the article! !

Java performance optimization notes: JVM performance monitoring and tuning articles

Memory structure

Program counter
Virtual machine stack
Native method stack
heap
Method area
Direct memory