Five Ali technical experts have been offered. How many interview questions can you answer

Interview position ：Java Back end Development Engineer .

It's really a bit of a rush before the interview , Three interviews in a week , And then I began to wait endlessly , I've been waiting for about three weeks , Finally, the four sides and HR Noodles . The whole process is quite tortuous , The technical interview is quite a survey of technical depth . Now I've got offer.

The interview questions are as follows ：

one side ( It's mainly about the basics )：

• Introduce yourself first , Talk about your basic knowledge , And project experience

• What data structures do you usually use ？

• Advantages and disadvantages of linked list and array ？

• solve hash What are the conflicting methods ？

• Tell me you're right HashMap The understanding of the , And the Weakhashmap The difference between ？

• What you just said is JDK1.7 Implementation of version , know JDK1.8 What changes have been made ？

• You use it in microservices RPC Communication or REST？

• RPC and HTTP What is the relationship of ？

• Talk about what is HTTP Long and short connections of ？

• TCP Three and four waves of , And why three handshakes , Not twice ？

• TCP  What are the States , Meaning of corresponding state ?

• And the implementation layer of lock in the contract （ Yes AQS The understanding of the ）？

• Understanding and Realization of optimistic lock and pessimistic lock , What are the ways to do it ？

• SynchronizedMap and ConcurrentHashMap What's the difference? ？

• How to implement a producer and consumer model using blocking queues ？

• Briefly Java  Garbage collection mechanism ？

• How to judge whether an object is alive ？

• What is? tomcat Class loading mechanism ？

• The mechanism of parent delegation model of classloader ？

• Let you evaluate yourself ？

Two sides ( Mainly asked the underlying and algorithm ):

• It's about the project 、 Tell me about the project experience

• redis What do you know about the underlying data structure of ？

• Know dynamic strings sds What are the advantages and disadvantages of (redis One of the underlying data structures )？

• redis What are the advantages and disadvantages of the single thread feature of ？

• Used to  Redis  Which data structures ,  What scenarios are used respectively ?

• How to solve the problem of cache breakdown ？

• Hytrix What are the isolation mechanisms of ？Hytrix What are the common configurations ？

• What tuning has been done ？JVM tuning 、 Database tuning is OK ！

• Gave a scene , Ask you how to adjust ？

On three sides ( database )：

• Still introduce yourself

• What is the high availability architecture of the database ？

• How to ensure the consistency of database master and slave ？

• know mysql The index algorithm of ？

• Why? mongodb The index of is used B Trees , and mysql use B+ Trees ？

• use mysql In the process , Do you have any problems ？

• What kind of transaction isolation level is used in production , Why? ？

• Talk about your understanding of microservice architecture ？

• Which have been used? RPC frame , Talk about their advantages and disadvantages ？

• Used to docker Do you , How much do you know about containers ？

Four sides ( On the side of Architecture )：

• Introduce yourself , Talk about project experience

• How to divide microservices in the project , How to determine the granularity ？

• In practice microservice architecture , What's the problem ？

• In terms of data consistency between microservices , How to solve it ？

• Why not use others MQ, Finally, I chose RokcetMQ？

• Why? RocketMQ no choice ZooKeeper, It's the realization of a NameServer colony ？

• Zookeeper In the course of the election , Can we still provide external services ？

• Yes Paxos How much does the algorithm know ？

• If you want to design a red envelope architecture for Spring Festival Gala , How would you design ？

• What do you want to ask me ？

Five sides (HR Noodles )：

Talk about life and ideals ,HR very ncie, Why did you choose to come to Ali , Future plans, career planning and salary, etc , It's been a lot of fun .

Interview summary ：

The technical foundation must be solid ： Algorithm 、 data structure 、 Operating system, etc , Ant financial interview attaches great importance to the basis of Technology , Students with a solid foundation are in favor of highlighting the encirclement in the first two rounds .

Technical width ： Mainly concentrated on high concurrency 、 Multithreading 、 Distributed architecture , Large and common middleware ( Cache, etc ) Selection and comparison of .

Technical principles go deep ： The point is to be prepared in advance JVM、 Multithreading and high concurrency .

Summary of the projects involved ： You need to be clear about the key details of your project 、 Optimize 、 characteristic 、 principle .

A lot of third-party libraries used & The principle of middleware , Even if you don't know , Also have your own ideas about how to replace the implementation , For example, an alternative to single sign on .

Last , Don't fall on HR Interview session , It's the key to avoid the heavy , Especially the advantages and disadvantages , If asked what your plan is , Please remember to tell HR You want to be an excellent technologist ！

Data acquisition method ： add to v yunduoa2019  Pack and take away all materials ~

Share some of my personal learning documents , Friends in need choose to get ：

a copy Java The core interview knowledge dictionary analyzes each knowledge point deeply , It should be very helpful , It takes most of Java Knowledge is gathered together and analyzed in depth （ It's highly recommended that we take a look at ）

• JVM

• JAVA aggregate

• JAVA Multithreaded concurrency

• JAVA Basics

• Spring principle

• Microservices

• Hetty And PC

• The Internet

• journal

• Zookeeper

• Kafks

• Rabbi tMQ

• Hbase

• MongoDB

• Cassandra

• Design patterns

• Load balancing

• database

• Consistency algorithm

• JAVA Algorithm

• data structure

• encryption algorithm

• Distributed cache

• Hadoop

• Spark

• Storm

• YARIN

• machine learning

• Cloud computing

2019 First line Internet enterprises in 350 Sorting out interview answers

• Performance optimization interview column

• Interview column of microservice Architecture

• Concurrent programming advanced interview column

• Open source framework interview column

• Distributed interview column

Interview scenes in big factories

1、 Organize interview documents

Since it's an interview , Then it's necessary to brush the questions , In fact, after the Spring Festival home , I can't go anywhere , I did a lot of interview questions myself , So in the interview process to be able to know , Basically, it will be clear what knowledge points will be asked during the interview , What are the high frequency questions , So brushing questions is a very important point in the pre interview preparation process .

According to their own interview experience and constantly collect （ Collector's Edition ）

Related ebooks 、 Bottom source

Alibaba must learn knowledge

Last

Many people sigh “ Learning is useless ”, In fact, the reason why there is the theory of uselessness , It's because what you want doesn't match what you learn , This means that I have not learned enough . Whether it's study or work , There should be initiative , So if you have a big factory dream , Then we should try our best to realize it .

All the above learning materials are free of charge , Finally, I wish you all good health , I got what I wanted offer！

Data acquisition method ：

add to v yunduoa2019  Pack and take away all materials ~