On the "Golden Nine Silver Ten", young graduates are full of hope and anxiety, looking for and competing for a job opportunity. The development students who are already on the job also want to get better treatment and a bigger platform through social recruitment or internal promotion.
However, there are a large number of interviewers, and the technical market is relatively cold. The students who are interviewed have to face the huge competition of N candidates for 1 position.
Q: Under this situation, how can we get more and better offers?
A: Short-term preparation - brushing interview questions; long-term planning - consolidating core skills.
How to brush the interview questions? Brush high-frequency questions, deep questions, and time-sensitive questions.
How to consolidate core skills? First in-depth understanding of the principle, and then systematically apply it to practice.
With the development of the Internet, high reliability, high concurrency, and cost reduction and efficiency enhancement have become realistic challenges faced by major companies. The need for optimal performance optimization is becoming more and more urgent, ranging from distributed systems to algorithms as small as code blocks. Optimization has become something that you must face in your daily work. For developers, performance optimization has also changed from a plus to a hot skill, and lack of relevant knowledge will make it difficult to stand out in interviews or jobs.
As the saying goes, if you know yourself and your enemy, you will be victorious in every battle. If you want to overcome the problem of "performance optimization", you must first understand the characteristics of performance optimization and grasp its key and essence. **As a mandatory part of the interview, many applicants reported that some of the interviewer's questions will make them ambiguous, **I don't know how to answer, for example, many people don't understand the difference between buffering and caching. The answer to this kind of question can only rely on systematic sorting, and it is not feasible to rely on scattered knowledge. You need to have the ability to deduce by analogy, in order to further sublimate the scattered knowledge of the interview with both depth and breadth, and only then will the interviewer's eyes shine.
When faced with these situations, you may only start by feeling, or think first, and fail to find and grasp the essence. Therefore, I specially share this set of "Java Back-end Performance Tuning Practical Collection" to explain and analyze the correct ideas. , so that you can rely on it when optimizing performance.
Java back-end performance tuning practical brain map
In **this set of "Java Backend Performance Tuning Practical Collection"**, the classic cases of Java performance optimization are summarized, combined with a large number of code examples, to try to restore the real business scenario for you.
Divided into 7 modules, a total of 20+W words, I will systematically explain from theoretical analysis, tool support, case and interview, as well as four aspects of actual combat:
**Module 1: Performance Optimization Concepts,** establishes two standards for you. One is the performance tuning standard, which tells you which parameters can be used to measure system performance; the other is the tuning process standard, which guides you to understand which strict tuning strategies are adopted so that we can troubleshoot performance problems and solve them.
**Module 2: Design Pattern Tuning, **In architecture design, we often use some design patterns to optimize the architecture design. Here I will combine some complex application scenarios and share design optimization cases.
**Module 3: Java programming performance tuning, **JDK is the basic knowledge of the Java language. Familiar with the tool classes in each JDK package can help you write high-performance code. Here I will start with the basic data types, involving the tuning of containers in practical application scenarios, as well as the more important network communication tuning in the current Internet system architecture.
**Module 4: Multi-threaded performance tuning, ** At present, most servers are multi-core processors, and multi-threaded programming is widely used. In order to ensure the safety of threads, synchronization locks are usually used, which will bury a lot of hidden dangers for the system; in addition, there are performance problems caused by high concurrency of multiple threads, which will be explained in this module.
**Module 5: JVM performance monitoring and tuning, **Java applications run on the JVM, and tuning the JVM can improve system performance. Here we focus on the creation and recycling of Java objects, memory allocation, etc.
**Module 6: Database Performance Tuning, **Database is most likely to become the performance bottleneck of the entire system. Here I will focus on analyzing some commonly used database tuning methods.
Summarize
As a past person, I found that many learners and practitioners are facing a lot of troubles in Java performance optimization, such as:
- When encountering the problem of "performance optimization" in the work scene, ** often can only rely on blind guessing and feeling,** use temporary remedies to cover up, it seems that the problem has been solved, but the same problem will occur again next time, the reason It is the lack of methodology, guidance of ideas, and tool support;
- In ability training, due to the perennial exposure to CRUD and the lack of a high-concurrency practical environment, the "performance optimization" can only be imagined through theoretical knowledge, and it is impossible to understand its true face and practical process in actual work;
- In the workplace promotion, only focus on functional development, do not understand the principle of component design, lack in-depth thinking and summary, cannot complete high-level work such as high-concurrency and high-performance system design , and it is difficult to flex your muscles at work, and challenging work is often For those who are prepared.
In short, once encountering the problem of "performance optimization", few people can reversely analyze it from point to point , and finally find the bottleneck point and optimization method. However, performance optimization is the deep water area of software engineering, and it is also a measure of a programmer's ability. standard.
