Three-sided Alibaba Technology Java post, already offered an offer, see how many of these interview questions you can answer

 

Foreword

Interview position: Java backend development engineer

Before the interview, the three sides were really a bit rushed. I finished the interview three times in a week, and then began to wait endlessly. After waiting for about three weeks, I finally completed the four sides and the HR side. The whole process is still tortuous, and the technical interview still looks at the technical depth. Now I have got an offer.

The interview questions are as follows:

One side (mainly looking at the foundation):

1. Introduce yourself first, talk about your basic grasp, and project experience
2. What data structures do you usually use?
3. The advantages and disadvantages of linked lists and arrays?
4. What are the ways to solve the hash conflict?
5. Tell me about your understanding of HashMap and the difference with Weakhashmap?
6. You just talked about the implementation of JDK1.7. Do you know what changes JDK1.8 made?
7. Do you use RPC communication or REST in microservices?
8. What is the relationship between RPC and HTTP?
9. Talk about what is the long connection and short connection of HTTP?
10. TCP's three-way handshake and four-way wave, and why do we need three-way handshake instead of two?
11. What are the status of TCP and the meaning of the corresponding status?
12. The underlying implementation of locks in concurrent packages (understanding of AQS)?
13. Optimistic lock and pessimistic lock understanding and how to achieve, what are the ways to achieve?
14. What is the difference between SynchronizedMap and ConcurrentHashMap?
15. How to implement a producer and consumer model using blocking queues?
16. Briefly describe the Java garbage collection mechanism?
17. How to judge whether an object is alive?
18. What is the tomcat class loading mechanism?
19. Class loader parent delegation model mechanism?
20. Let you evaluate yourself?

Two sides (database):

• Still introduce yourself
• What is the high availability architecture of the database?
• How to ensure the master-slave consistency of the database?
• Do you know the indexing algorithm of mysql?
• Why does mongodb's index use B-trees and mysql uses B + -trees?
• Are there any problems encountered during the use of mysql?
• What transaction isolation level is used for production and why?
• Talk about your understanding of microservice architecture?
• What RPC frameworks have you used and talk about their advantages and disadvantages?
• Have you used docker, how much do you know about containers?

Three sides (partial architecture):

• Introduce yourself and talk about project experience
• How are microservices divided in the project, and how is the granularity determined?
• What are the problems encountered in the practice of microservice architecture?
• How to solve the problem of data consistency between microservices?
• Why not use other MQ, and finally chose RokcetMQ?
• Why didn't RocketMQ choose ZooKeeper, but implemented a NameServer cluster by itself?
• Can Zookeeper provide external services during the election process?
• How much do you know about the Paxos algorithm?
• If you were to design a red envelope architecture for the Spring Festival Gala, how would you design it?
• What do you want to ask me?

(HR side):

Talking about life and talking about ideals, HR is very ncie. The main exchange is why I chose to come to Alibaba. The future plans for career planning and treatment are very pleasant.

Interview summary:

The technical foundation must be solid: algorithms, data structures, operating systems, etc., Ant Financial interviews attach great importance to the foundation of technology, and students with solid foundations are conducive to highlighting the encirclement in the first two rounds.

Technical width: Mainly focus on the selection and comparison of high concurrency, multi-threading, distributed architecture, large and commonly used middleware (cache, etc.).

The technical principle is in-depth: the key is to prepare the JVM and multi-thread high concurrency in advance.

Summary of participating projects: You need to know the key details, optimization, characteristics, and principles of the projects you are doing.

Many of the principles of third-party libraries & middleware used, even if you do n’t know, should have their own ideas to show how to replace the implementation, such as single sign-on alternatives.

Finally, do n’t fall into the HR interview session. Avoiding the lesser is the key, especially the advantages and disadvantages. If you are asked about your plan, please remember to tell HR that you want to be an excellent technical expert!

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Share a wave of my interview collection

21 days after eating 283 pages of pdf

Java part: Java basics, collection, concurrency, multithreading, JVM, design pattern

Data structure algorithm: Java algorithm, data structure

Open source framework: Spring, MyBatis, MVC, netty, tomcat

Distributed part: architecture design, Redis cache, Zookeeper, kafka, RabbitMQ, load balancing, etc.

Microservices : SpringBoot, SpringCloud, Dubbo, Docker

 

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350 interview answers for first-tier Internet companies in 2019

1. Performance optimization interview column
2. Microservice architecture interview column
3. Concurrent programming advanced interview column
4. Open source framework interview question column
5. Distributed interview column

 

Interview scene of Dachang

 

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1. Topical arrangement of interview documents

Since it ’s an interview, brushing the questions is indispensable. In fact, I ca n’t go anywhere after the Spring Festival home. I ’ve brushed a lot of interview questions myself, so I ’ve been able to do well in the interview process. During the interview process, you will be asked what knowledge points and what are the high-frequency questions, so brushing questions is a very important point in the preliminary preparation process of the interview.

According to their own interview experience and constantly collected (collector's edition)

 

Related e-books, underlying source code

 

Alibaba must learn knowledge points

 

Conclusion

For the interview of big factories, the last thing I want to emphasize is that mentality is really important. It is the key to determine your play in the interview process. If you ca n’t play normally, it is likely that a small mistake and the offer are missing, so you must pay attention to it stand up. Another reminder is that full review is the key to eliminating your nervous state, but if you review enough, you will naturally have a lot of confidence in the interview process.

All the learning materials and interview materials in the above content can be provided free of charge. I hope everyone will have a good interview with gold, silver and four and win their favorite offer!