In 1994, my younger brother returned from the interview and finally got the Offer from Ant Financial in three months

The intermittent interview really exhausted me physically and mentally, and also deeply realized the shortcomings of my own technology stack. So AT the end of each interview, I would summarize carefully. Constantly on the Internet to find information to improve their own. The more interviews you have, the more you will find that the interview as a whole is just a stack. When we have direction and plan to improve ourselves, we will grow quickly.

Here’s a summary of more than two dozen interviews, big and small. Hope to bring you some help.

• What about design patterns? What do you know?

• Implement a single column pattern.

• What is the Simple Factory pattern?

• What is the Abstract Factory pattern?

• What is the observer model?

• What is the decorator pattern?

• What is the template method pattern?

• And so on, 23 common design patterns can be asked…..

• What are the design goals, philosophy, and core of the Spring framework

• What are the advantages and disadvantages of Spring?

• What are the applications of Spring

• What modules does Spring consist of?

• What design patterns are used in the Spring framework?

• Take a closer look at the core Container (Spring Context application Context) module

• What are the different types of events in the Spring framework

• What are the different components of a Spring application?

• What are some ways to use Spring?

• What is the Spring IOC container?

• What does inversion of control (IoC) do

• What are the advantages of IOC?

• Implementation mechanism of Spring IoC

• What features does Spring’s IoC support

• What’s the difference between BeanFactory and ApplicationContext?

• How does Spring design the BeanFactory and ApplicationContext context

• What is the usual implementation of ApplicationContext?

• What is Spring’s dependency injection?

Wait, several other interviewers have asked me if I have read the Spring source……

• Disadvantages of MyBatis framework:

• MyBatis framework for applications

• What are the differences between MyBatis and Hibernate?

• What is the difference between #{} and ${}

• What if the attribute name in the entity class is different from the field name in the table?

• Does Mybatis support lazy loading? If so, how does it work?

• Mybatis level 1 cache and level 2 cache principle

• What is interface binding for MyBatis? What are the implementation methods

• What are the requirements when using MyBatis mapper interface

And so on…

• What is Spring Boot?

• What are the advantages of Spring Boot?

• What are the core annotations for Spring Boot? Which notes are it mainly composed of?

• What is the principle of Spring Boot automatic configuration?

• How do you understand the Spring Boot configuration loading order?

• What is YAML?

• What are the advantages of YAML configurations?

• Can Spring Boot be configured using XML?

• What is the Spring Boot core configuration file? What is the difference between bootstrap.properties and application.properties?

And so on…

• MySQL replication principle and process

• MySQL myISam vs. InnoDB

• Varchar (50); varchar(50); char(50)

• Innodb transaction and log implementation

• MySQL binlog format

• Does your database support emoji? If not, how do you operate?

• How do you monitor your database? How do you search your slow logs?

• Which is faster, InooDB or MyISAM select count (*)? Why

• Why does mysql use autoincrement columns as primary keys

• B+ tree index and hash index difference

• Mysql optimization

And so on…

• When can stack memory overflow occur

• Detail the JVM memory model

• Why is JVM memory divided into new generation, old generation, persistent generation

• Why are the new generation Eden and Survivor

• What does a complete GC flow look like in the JVM

• How does the target get promoted to the old age

• You know which garbage collectors, each with its pros and cons

• Focus on CMS and G1, including principles, processes, advantages and disadvantages

• Knowledge of the JVM memory model, such as reordering, memory barriers, happening-before, main memory, working memory.

• Tell me briefly what you know about classloaders, can they break parental delegation and how. The JVM to optimize

• And so on…

• What is the default port of Tomcat and how to change it?

• What are the tomcat Connector operating modes (optimizations)?

• How many deployment modes can Tomcat be used?

• How does the Tomcat container create instances of servlet classes? What principles are used?

• How is Tomcat optimized?

• What is Netty? Have you ever used Netty?

• What are the characteristics of Netty?

• What is Netty zero copy?

• The advantages of Netty?

• Netty application scenarios?

• What is Netty’s high performance?

• What are the key components in Netty?

• How many ways does Netty send messages?

• How many threads does Netty have by default? When does it start?

• What’s a Dubbo? Why Dubbo?

• What’s the difference between Dubbo and Spring Cloud?

• What protocols does Dubbo support and which are recommended?

• What kinds of service containers are built into Dubbo?

• What types of node roles are there in Dubbo?

• What registry does Dubbo use by default? Any other options?

• What are the main configuration items of Dubbo and what are their functions?

• Dubbo has several fault tolerant mechanisms

• Dubbo’s service was downgraded

• Dubbo priority configuration

• And so on…

• What is ZooKeeper?

• What does ZooKeeper offer?

• Zookeeper file system

• ZAB agreement?

• Four types of data nodes zNodes

• Zookeeper Watcher mechanism – Data change notification

• The client registers the Watcher implementation

• The server handles the Watcher implementation

• The client calls back Watcher

• How does ZooKeeper keep the order of transactions consistent?

• Why is there a Master in a distributed cluster?

• What can I do if the ZK node is down?

• Zookeeper load balancing differs from NGINx load balancing

• What are the deployment modes of Zookeeper?

• And so on…

• What are the types of NoSQL databases?

• What are the basic differences between MySQL and MongoDB?

• What is the role of profilers in MongoDB?

• A:{B,C} A:{B,C} A:{C,B} A:{C,B}

• Does MongoDB support stored procedures? If so, how to use it?

• How to understand the GridFS mechanism in MongoDB and why MongoDB uses GridFS to store files?

• How do sharding and replication work?

• At what point does data expand into multiple shards?

• What if I launch a query when a shard is stopped or slow?

• And so on…

• Redis persistence mechanism

• Cache avalanche, cache penetration, cache warming, cache update, cache degradation and other issues

• What is hot data and cold data

• What are the differences between Memcache and Redis?

• Why is single-threaded Redis so fast

• The data types of Redis, as well as the usage scenarios of each data type, redis internal structure

• Redis expiration strategy and memory flushing mechanism

• Why is Redis a single threaded advantage

• How to solve the redis concurrent competing key problem

• What should Redis cluster solution do? What are the options?

• Have you attempted a multi-machine Redis deployment? How to ensure data consistency?

• How to handle the large number of requests

• Redis Common performance issues and solutions?

• Explain the Redis threading model

• Why are Redis operations atomic and how are they guaranteed to be atomic?

• Redis transactions

• Redis implements distributed locking

• And so on…

• What is SpringCloud? What are the advantages of using Spring Cloud?

• What do I mean by service registration and discovery? How is Spring Cloud implemented?

• What does load balancing mean? What is Ribbon?

• What is Hystrix? How does it achieve fault tolerance?

• What is Netflix Feign? What is Open Feign?

• What is Spring Cloud Bus?

• What is a service circuit breaker? What is service degradation?

• The difference between Eureka and ZooKeeper

• What is Spring Cloud Gateway?

• What is zuul Routing Gateway?

• What is a distributed configuration center?

• And so on…

• Why kafka? Why message queues

• What do ISR and AR stand for in Kafka? What is scaling of ISR

• What is a broker in Kafka

• How do Kafka followers synchronize data with the Leader

• What is the role of ZooKeeper in Kafka?

• What is the role of ZooKeeper in Kafka?

• Kafka’s producer workflow

• Kafka’s consumer workflow

• Scenarios of data loss and repeated consumption

• How is Kafka data loss, high reliability and consistency achieved

• How to solve the problem of data loss and repeated data consumption on the consumer side

• And so on…

• What is RabbitMQ?

• Rabbitmq usage scenarios

• RabbitMQ basic concepts

• The working mode of RabbitMQ

• How can RabbitMQ messages be ordered?

• How are messages distributed?

• How are messages routed?

• What transport is the message based on?

• How to ensure that messages are not re-consumed? In other words, how can messages be idempotent when consumed?

• How do I ensure that messages are sent to RabbitMQ correctly? How do I ensure that message recipients consume messages?

• And so on…

• Who is RocketMQ made up of?

• RocketMQ executes the process

• What do you know about Producer?

• Tell me what you know about Consumer?

• How many consumer consumption patterns are there?

• How many modes are there for consumers to get messages?

• What is a timed message? How to do that?

• How does RocketMQ ensure high availability?

• How to ensure that messages are not re-consumed? Or how to ensure idempotency when consuming messages?

• How to ensure the reliable transmission of messages? What if the message gets lost?

• How do I ensure that messages are sequential?

• How to solve message queue delay and expiration problem?

• What happens when the message queue is full? There are millions of messages waiting for hours. How do you fix them?

• And so on…

• What is Mycat? How does Mycat work?

• What is a ShardingSphere? How does ShardingSphere work?

• What is horizontal splitting? What is vertical split?

• Explain global table, ER table, shard table?

• When we split the database table, how to choose the split rules?

• What is the difference between Mycat and ShardingSphere?

• And so on…

• Pros and cons of concurrent programming

• Threads are different from processes

• There are four ways to create threads

• Java memory model

• Concurrency keywords synchronized, volatile, and final

• What are CAS, AQS, ReentrantLock,

• ReentrantReadWriteLock

• Concurrent container ConcurrentHashMap, SynchronizedMap, CopyOnWriteArrayList, ThreadLocal, BlockingQueue, ConcurrentLinkedQueue, ArrayBlockin GQueue and LinkedBlockingQueue

• Thread pool-related issues

• Concurrent tool

• And so on…

Concurrent programming related knowledge points asked a lot, not a list, anyway, I asked very meng forced ~

• What is Nginx and what does it do?

• Nginx comes with load balancing rules

• How does Nginx configure dynamic/static separation server

• Nginx security configuration mode

• The difference between FastCGI and CGI?

• Nginx common command?

• What are forward and reverse proxies

• How does Nginx achieve high concurrency

• And so on…

• How does Nginx handle HTTP requests

• What’s the difference between a Docker and a virtual machine?

• What is a Docker image

• Docker containers have several states

• Explain the ONBUILD directive for dockerfile

• How do I monitor Docker in production

• Docker and K8s related knowledge points are relatively few, so I have a general understanding.

• What is Kubernetes? What does it have to do with Docker?

• How does Kubernetes simplify containerized deployment?

• How much do you know about Kubernetes clustering?

In order to complement my weak tech stack, I struggled to buy or procure many high-quality resources online.