Jianzhi Ali P6 interview 168 questions summary: JVM + microservices + multithreading + high concurrency performance (collection)

Near the end of the new year, many students left messages saying that the interview was not going well recently. They were asking me if I had any interview questions that were frequently used by major companies in 19 years. I wanted to brush up on the questions during the holiday and try again after the year.

 

In fact, I usually collect interview information from major companies (for emergencies), and combined with the sharing of fans and friends, I have compiled dozens of interview questions from Tencent, Toutiao, Ali, Meituan and other companies in 19 years , The following is a display of some interview questions:

1. Redis interview questions (interview answers are attached at the end of the article)

1. What is Redis?
2. What are the benefits of using Redis?
3. What are the advantages of Redis over Memcached and what are the differences?
4. What is the persistence mechanism of Redis? Their advantages and disadvantages?
5. Redis common performance problems and solutions:
6. Redis recycling strategy (elimination strategy)?
7. Do you understand the synchronization mechanism of Redis?
8. Have you used Redis cluster? What is the principle of cluster?
9. Under what circumstances will the Redis cluster solution cause the entire cluster to be unavailable?
10. Talk about the concept of Redis hash slot?

2. Dubbo interview questions (interview answers are attached at the end of the article)

1. What is Dubbo and why use Dubbo?
2. What protocol does dubbo support and which one is recommended?
3. What kind of service containers are built in Dubbo?
4. Draw a flow chart of service registration and discovery
5. What registry does Dubbo use by default, are there other options?
6. What are the configuration methods of Dubbo and what are the core configurations?
7. What happens if the dependent services are unavailable when Dubbo starts?
8. What serialization framework Dubbo recommends and what else do you know?
9. What kind of cluster fault tolerance solutions does Dubbo have, and which is the default?
10. What kinds of load balancing strategies does Dubbo have, and which is the default?

3. Spring Boot interview questions (the interview answers are attached at the end of the article)

1. What is Spring Boot?
2. What are the advantages of Spring Boot?
3. How to reload changes on Spring Boot without restarting the server?
4. What is the monitor in Spring Boot?
5. How to realize the security of Spring Boot application?
6. How to integrate Spring Boot and ActiveMQ?
7. What is Swagger? Have you implemented it with Spring Boot?
8. What is a FreeMarker template?
9. What is a CSRF attack?
10. How do we monitor all Spring Boot microservices?

4. Spring Cloud interview questions (interview answers are attached at the end of the article)

1. What is Spring Cloud?
2. What are the advantages of using Spring Cloud?
3. What does service registration and discovery mean? How to achieve Spring Cloud?
4. What is the significance of load balancing?
5. What is Hystrix? How does it achieve fault tolerance?
6. What is a Hystrix circuit breaker? Do we need it?
7. What is Netflix Feign? What are its advantages?
8. What is Spring Cloud Bus? Do we need it?

5. JVM interview questions (interview answers are attached at the end of the article)

1. Three JVM performance tuning parameters, how many important parameters are JVM?
2. JVM memory management, JVM's common garbage collector, G1 garbage collector. GC tuning, Minor GC, Full GC trigger conditions
3. Java memory model
4. Java garbage collection mechanism
5. How does the jvm judge whether an object is recyclable and what kind of object can be used as the GC root
6. OOM tell me? How to troubleshoot? What causes OOM? When does OOM appear
7. What is Full GC? GC? major GC? stop the world
8. Describe a full gc process in JVM.
9. In the JVM, the class loading mechanism, the class loading process, what is the parent delegation model? , What are the class loaders
10. How to judge whether there is a memory leak? What are the ways to locate the cause of Full GC?

6. Java concurrent programming (with interview answers at the end of the article)

1. What is the difference between daemon thread and local thread in java?
2. The difference between thread and process?
3. The difference between deadlock and livelock, the difference between deadlock and starvation?
4. What is a thread group, and why is it not recommended in Java?
5. How to find which thread uses the longest CPU time on Windows and Linux?
6. What is an atomic operation? What are the atomic classes in the Java Concurrency API?
7. What is the Lock interface in the Java Concurrency API? What are its advantages over synchronization?
8. What is a blocking queue? What is the realization principle of blocking queue? How to use blocking queues to implement the producer-consumer model?
9. There are several ways to achieve multi-thread synchronization and mutual exclusion, what are they?
10. What are race conditions? How do you discover and resolve competition?

 

At last

I believe that this year, whether it is now, or in March or April, there will be a constant wave of resignations and job hunting. As a job seeker, the interview is a hurdle. Many people will fear the interview. Even programmers who have been working for many years may still have interview anxiety.

Therefore, for the 2020 "Golden Three Silver Four" interview hopping season, today I will share a wave of benefits on the official account, which contains compiled interview information from major Internet companies such as ATM, and some information about the Internet. Mainstream architecture technical materials, mainly explain videos on technologies such as Java distributed, high concurrency, source code analysis, spring, and performance optimization.

This set of materials is especially suitable for the following groups:

1. No work experience, but very solid foundation, proficient in java working mechanism, common design ideas, and common java development framework.
2. Those who have certain work experience, but do not know where to start in the face of the current popular technology, and need to quickly improve their core competitiveness.
3. I have been in the company for a long time and have a very comfortable life, but the interview hit a wall when I changed jobs. Those who need to study in a short period of time and change jobs to get a high salary can sign up.
4. Want to understand the latest recruitment needs/technical requirements of "first-line Internet companies", compare and find out their strengths and weaknesses, and evaluate their competitiveness in the existing market;
5. I have been doing Java development for several years, but have not yet formed a systematic Java knowledge system, and lack a clear improvement direction and learning path programmers.

Not much to say, directly upload the dry goods (the information will be updated continuously, subject to downloading) to receive for free~

I deliberately sorted out the following technologies. There are many technologies that cannot be explained clearly by a few sentences, so I just found some friends to record some videos. If you want to know what is happening, you must know why. If you want to learn Java engineering, high performance and distributed, explain the profound things in a simple way. Friends of performance tuning, Spring, MyBatis, Netty source code analysis can follow me

 

Share the most complete and latest interview documents, learn about large-scale Internet interview questions and answers first, and if you are interested in the summary of the interview document, you can like it, and follow my private message [Interview] to obtain (not easy to organize) large-scale Internet company interview answers for details!

Summary of interview questions

 

Part of the interview video