The Java back-end development interview summary I shared includes 25 special technical points such as JavaOOP, Java collection container, Java exception, concurrent programming, Java reflection, Java serialization, JVM, Redis, Spring MVC, MyBatis, MySQL database, message middleware MQ, Dubbo, Linux, ZooKeeper, distributed & data structure and algorithm. Summarize and share with everyone here!
The length of my sharing may be a bit long, friends who watch it can learn about the catalog first
JavaOOP Interview Questions
Java Collections/Generic Interview Questions
Java Exception Interview Questions
IO and NIO in Java Interview Questions
Java Reflection Interview Questions Java Serialization Interview Questions Java Annotation Interview
Questions Multithreading
&
Concurrency Interview Questions
JVM Interview Questions
Mysql Interview
Questions Redis Interview Questions
Memcached Interview Questions
MongoDB
Interview Questions String
Spring Cloud Interview Questions
RabbitMQ Interview Questions
Dubbo Interview Questions
MyBatis Interview Questions
ZooKeeper Interview Questions
Data Structure Interview
Questions Algorithm Interview Questions
Elasticsearch Interview Questions
Kafka Interview Questions
Microservice Interview Questions
Linux Interview Questions
Due to the limited space, there are only some interview questions for each topic interview question. The following is a collection
1. JavaOOP interview questions
1. Is short s1 = 1; s1 = s1 + 1; wrong? Short s1 = 1; s1 += 1; Is it wrong?
2. The difference between overloading and rewriting
3. How many ways are there to instantiate an array?
4. Default values of various data in Java
5. What are the commonly used methods of the Object class?
6. Is passing by reference passed by value in java?
7. The difference between formal and actual parameters
8. Can the construction method be rewritten? Can it be overloaded?
9. What is the difference between an inner class and a static inner class?
10. What does the Static keyword do?
11. What are the functions and usages of final in java?
12. Is String str="aaa" the same as String str=new String("aaa")?
13. Tell me about the common methods of the math class in java?
14. Can Char type be converted into int type? Can it be converted into string type, can it be converted into double type
15. What is unpacking?
16. What are the wrapper classes in Java?
17. What is included in a java class?
18. How do you solve the problem of errors in floating-point data operations?
19. What are the characteristics of object-oriented?
20. What is the difference between access modifiers public, private, protected, and not written (default)?
21. What are the characteristics of the interface?
22. What is the difference between an abstract class and an interface?
23. The role of Hashcode
24. What is the difference between ordinary classes and abstract classes?
25. What is an interface? Why do you need an interface?
26. What are the characteristics of the interface?
27. What is the difference between copy and shallow copy?
28. Steps of JDBC operation
29. When to use assert
30. Does an array have a length() method? Does String have a length() method?
31. Use the most efficient method to calculate how much is 2 times 8?
32. What is the difference between String, StringBuilder and StringBuffer?
33. Can the interface inherit (extends) the interface? Can abstract classes implement (implements) interfaces? Can an abstract class inherit from a concrete class?
34. Can a ".java" source file contain multiple classes (not inner classes)? What are the restrictions?
35. What are the uses of the final keyword in Java?
2. Java collection/generic interview questions
1. The difference between ArrayList and linkedList
2. HashMap sorting question
3. Collection package structure, the difference from Collections
4. Constructor with set parameters
5. Talk about the difference between List, Set, and Map
6. How is concurrent collection different from normal collection?
7. What are the characteristics of Map
8. The collection class is stored in the Java.util package, and there are mainly several interfaces
9. What is the list interface
10. Talk about ArrayList (array)
11. Vector (array implementation, thread synchronization)
12. Talk about LinkList ( linked list )
13. What is the Set collection?
14, HashSet ( Hash table)
15. What is TreeSet ( binary tree )
16. What is the difference between List, Map and Set?
17. What scenarios are arrays and linked lists suitable for, and why?
18. Talk about ConcurrentHashMap
19. What is the difference between ArrayList and LinkedList in Java?
20. TreeMap ( sortable )
21. Please use two queues to simulate the stack structure?
22. Can the key and value in Map be null?
23. Doubly linked list based on data structure
24. The underlying implementation of HashMap
25. The difference between ConcurrentHashMap and Hashtable
26. State the storage performance and characteristics of ArrayList, Vector, LinkedList
27. What collection classes do you know? main method?
28. HashMap principle, what changes did java8 make
29. What is the difference between the poll() method and the remove() method?
30. Write a piece of code to remove an element while traversing the ArrayList
3. Java exception interview questions
1. What are the two types of exceptions in Java?
compile time exception
runtime exception
2. How many exception handling mechanisms are there?
Exception capture: try...catch...finally, exception throwing: throws. public class Box { private T t; public void add(T t) { this.t = t; } public T get() { return t;
3. How to customize an exception
Inherit an exception class, usually RumtimeException or Exception
4. Try catch fifinally, there is return in try, is finally still executed?
Execution, and the execution of finally is earlier than the return in try
in conclusion:
1. No matter whether there is an exception or not, the code in the finally block will be executed;
2. When there is return in try and catch, finally will still be executed;
3. finally is executed after the expression operation after return (at this time, the value after the operation is not returned, but the value to be returned is saved first, regardless of the code in finally, the returned value will not change, it is still the value saved before), so the return value of the function is determined before the execution of finally;
4. It is best not to include return in finally, otherwise the program will exit early, and the return value is not the return value saved in try or catch.
5. Excption and Error package structure
6. The difference between Thow and thorws
7. What is the difference between Error and Exception?
8. What is the difference between error and exception
9. What is the difference between final, finally, and finalize?
10. Understanding of Java exception handling mechanism?
11. Name the 5 most common RuntimeExceptions?
12. What is the difference between throw and throws?
13. Exception and Error interview questions in JAVA
14. What are the best practices you follow in Java exception handling?
15. What is the difference between the two keywords throw and throws in java?
16. Have you ever custom implemented exceptions? How do you write it?
17. Have you encountered OutOfMemoryError? How did you do it?
18. The simple principle and application of the exception handling mechanism in Java.
19. The five most common runtime exceptions.
20. How does the JAVA language handle exceptions? What do the keywords: throws, throw, try, catch, and finally represent? Can an exception be thrown inside a try block?
4. IO and NIO interview questions in Java
1. IO stream in Java?
2. How to convert byte stream to character stream?
3. What are the commonly used io classes?
4. How to serialize a java object into a file?
5. Blocking IO model
6. What is the difference between byte stream and character stream?
7. Multiplexing IO model
8. How to implement object cloning?
9. Asynchronous IO model
10. What is java serialization and how to implement java serialization?
11. NIO buffer
12. Stream-oriented and Buffer-oriented
13、Channel
14. How does NIO and IO affect the design of the application
15、Selector
16. The difference between Java IO and NIO
17. The difference between byte stream and character stream
18. Non-blocking IO model
19. Signal-driven IO model
20. NIO's non-blocking
21、Buffer
22、JAVA NIO
5. Java reflection interview questions
1. What is reflection?
2. Is it more efficient to create objects through Java reflection or to create objects through new?
3. What is object serialization, what is deserialization, and what needs to be done to realize object serialization?
4. Where will the reflection mechanism be used?
5. What are the advantages and disadvantages of the reflection mechanism?
6. Classes that implement Java reflection:
7. What is a dynamic proxy? What are the applications?
8. Java Reflection API
9. How to use Java reflection?
10. There are several ways to get the Class object
11. In addition to using new to create objects, what other methods can be used to create objects?
12. The role of java reflection
13. Implementation of reflection:
14. Reflection usage steps (acquire Class object, call object method)
6. Java serialization interview questions
1. What is java serialization?
2. Save (persist) the object and its state to memory or disk
3. Serialized objects are kept as byte arrays - static members are not saved
4. Serializable implements serialization
5. Serialized ID
6. Serialize user remote object transmission
7. WriteObject and readObject custom serialization strategy
8. Serialization does not save static variables
9. Serialization (implemented in deep clone)
10. The Transient keyword prevents the variable from being serialized into the file
11. How to implement java serialization?
12. The Transient keyword prevents the variable from being serialized into the file
13. Serialization of static variables?
7. Java annotation interview questions 1. What are the four standard meta-annotations?
2. What are annotations? What are their typical use cases?
3. Describe some useful annotations from the standard library.
4. What are annotations?
5. What object types can be returned from an annotated method declaration?
6. Which program elements can be commented?
7. Is there a way to limit the elements to which annotations can be applied?
8. What is a meta-annotation?
9. What is a duplicate comment?
10. How can you retrieve notes? How does this relate to retention policies?
11. Q11, is it possible to expand annotations?
8. Multithreading & Concurrency Interview Questions
1. What is a thread?
2. Inherit the Thread class
3. How to implement threads in java
4. ExecutorService, Callable, and Future have return value threads
5. What is the difference between multi-threaded Thread and Runnable?
6. 4 thread pools
7. Explain volatile variables in java
8. What is the difference between notify() and notifyAll()?
9. What is the difference between sleep() and wait()?
10. What is volatile? Can order be guaranteed?
11. What is the difference between the start() and run() methods in the Thread class?
12. Why are the methods wait, notify and notifyAll not in the thread class?
13. Shared locks and exclusive locks
14. What is the difference between interrupted and isInterruptedd methods in Java?
15. What is the difference between synchronized and ReentrantLock in Java?
16. There are three threads T1, T2, T3, how to ensure sequential execution?
17. What is the difference between SynchronizedMap and ConcurrentHashMap?
18. What is thread safety
19. Heavyweight lock (Mutex Lock)
20. What is the difference between the submit() and execute() methods in the Java thread pool?
21. Bias lock
22. Tell me how you use the synchronized keyword. Have you used it in the project? The three main ways to use the synchronized keyword
23. What is thread safety? Is Vector a thread-safe class?
24. There are several ways to implement multithreading in Java
25. Implement the Runnable interface.
26. Method based on thread pool
27. How to stop a running thread
28. Basic thread method
29. Thread yield (yield)
30. Thread wakeup (notify)
Due to the limited space, there are ways to obtain the complete interview questions and answer analysis at the beginning and at the end of the article.
Nine, JVM interview questions
1. JVM runtime memory
2. In 64-bit JVM, what is the maximum length of int?
3. The new generation, the old generation, and the permanent generation
4. For 32-bit and 64-bit JVM, what is the maximum length of int type variable?
5. JAVA8 and metadata
6. Generational collection algorithm
7. How to judge whether the JVM is 32-bit or 64-bit through a Java program?
8. Generational collection algorithm
9. What is the difference between JRE, JDK, JVM and JIT?
10. Explain Java heap space and GC?
11. JVM memory area
12. JAVA strong reference, soft reference, weak reference, phantom reference
13. Virtual machine stack (thread private)
14. Generational collection algorithm
15. Can you guarantee GC execution?
16. How to get the memory used by the Java program? % of heap used?
17. In the old generation - mark finishing algorithm
18. Describe the principle mechanism of JVM loading class files
19. Serial Old Collector (Single-threaded Marking Algorithm
20. Heap (Heap-thread sharing) - runtime data area
21. G1 collector
22. JVM class loading mechanism
23. The difference between heap and stack
24. What is a Java virtual machine? Why is Java called a "platform-independent programming language"?
25. Parallel Old Collector (Multithreaded Marking Algorithm )
26. Garbage collection algorithm
27. When do Minor GC and Full GC occur respectively?
28. What JVM performance tuning do you know
29. Tell me about the main components of the JVM and their functions?
30. What are queues and stacks? What's the difference?
10. Mysql interview questions
1. What are the different tables in MySQL?
2. TokuDB (Fractal Tree-node with data)
3. What are the names of the four transaction isolation levels supported by InnoDB in MySQL, and the differences between them?
4、Memory
5. What is myisamchk used for?
6. Where will MyISAM tables be stored and also provide their storage format?
7. Index
8. The common indexing principles are
9. How to display the first 50 rows?
10. First normal form (1st NF - the columns are all indivisible)
11. Second normal form (2nd NF- each table only describes one thing)
12. The third normal form (3rd NF - there is no transitive dependency on non-primary key columns)
13. Lock optimization strategy
14. SQL optimization
15. Select the appropriate data type for the fields in the table
16. What is a view
17. Under what circumstances is the index set but cannot be used
18. What are the problems caused by concurrent transactions?
19. What parts does the SQL language include? What is the key to the operation of each part
20. What is a lock?
21. What are the methods for optimizing SQL statements?
22. What are optimistic locks, pessimistic locks, timestamps, row-level locks, table-level locks, and page-level locks
12. Memcached interview questions
1. What is Memcached and what is its function?
2. Compared with MySQL's query cache, what are the advantages and disadvantages of memcached?
3. But I really need to dump all the items in memcached, and I really need to load the data into memcached, what should I do?
4. How does memcached authenticate?
5. How to use multithreading of memcached? How to use them?
6. What is the maximum length of the key that memcached can accept? (250bytes)
7. What restrictions does memcached have on item expiration time? (Why the 30-day limit?)
8. What is the maximum size of a single item that memcached can store? (1M byte)
9. Why is the size of a single item limited to 1M byte?
10. In order to make memcached use the memory of the server more effectively, can cache spaces of different sizes be configured on each server?
11. What is the binary protocol? Is it worth paying attention to?
12. How does memcached allocate memory?
13. Why not use malloc/free! ?
14. Why use slab?
15. Can memcached guarantee the atomicity of data storage?
Thirteen, MongoDB interview questions
1. What is mongodb?
2. Which language is MongoDB written in?
3. What do you mean by NoSQL database?
4. What are the types of NoSQL databases?
5. How do you compare MongoDB, CouchDB and CouchBase?
6. What makes MongoDB the best NoSQL database?
7. What is the most basic difference between MySQL and MongoDB?
8. Will the journal playback encounter problems when the entry is incomplete (for example, there happens to be a midway failure)?
9. What is the role of analyzers in MongoDB?
10. What is a namespace?
11. If a user removes an attribute on an object, is that attribute removed from the storage layer?
12. Is null value allowed?
13. Can the log feature be used for safe backup?
14. Does the update operation immediately fsync to disk?
15. Why is my data file so huge?
16. How to execute transactions/locks?
17. What is the difference between NoSQL and RDBMS?
18. Why use and not use NoSQL database?
19. Tell me about the advantages of NoSQL databases?
20. What are the characteristics of mongodb?
14. String interview questions
Spring Boot interview questions
1. Is String a basic data type?
2. What is Spring Framework?
3. If String is variable?
4. What are the different functions of Spring Framework?
5. How to compare the values of two strings are the same, how to compare whether two strings are the same object?
6. What is a Spring configuration file?
7. What are the different components of a Spring application?
8. What are the ways to use Spring?
9. tring str = new String("abc"); created several objects, why?
10. What is dependency injection?
11. Which characters are removed by the String.trim() method?
12. Can I customize the java.lang.String class and use it?
13. How many IOC containers are there in spring?
14. Distinguish between BeanFactory and ApplicationContext.
15. List some benefits of IoC.
16. The implementation mechanism of Spring IoC.
17. What configuration methods does spring provide?
18. What is a spring bean?
19. Does spring support centralized bean scope?
20. What is the inner bean of spring?
21. What is spring assembly
22. What is the life cycle of the spring bean container?
23. What are the ways of automatic assembly?
24. How to start annotation assembly in spring?
25. What are the limitations of automatic assembly?
26、@Component, @Controller, @Repository
27. What is annotation-based container configuration
28. What is the use of @Required annotation?
29. List the exceptions thrown by Spring DAO.
30. What is the use of @Qualifier annotation?
31. What is the use of @Autowired annotation?
32. What is the use of spring DAO?
33. What is the use of @RequestMapping annotation?
34. What classes exist in the spring JDBC API?
15. Spring Cloud interview questions
1. What is Spring Cloud?
2. What is the meaning of load balancing?
3. What is Spring Cloud Bus? do we need it
4. What is a Hystrix circuit breaker? do we need it
5. What is Hystrix? How does it achieve fault tolerance?
6. What is Netflix Feign? What are its advantages?
7. What is a service circuit breaker? What is service degradation
8. Both Eureka and zoo keeper can provide service registration and discovery functions. Please talk about the difference between the two?
9. What is microservice
10. What is a Hystrix circuit breaker? do we need it
11. What is the difference between spring cloud and dubbo?
12. What is the difference between SpringBoot and SpringCloud?
13. What is the difference between spring cloud and dubbo?
14. Talk about the realization principle of RPC
15. How do microservices communicate independently?
16. What are the advantages of using Spring Cloud?
17. Comparison between REST and RPC
18. What microservice technology stack do you know?
16. RabbitMQ interview questions
1. What is rabbitmq
2. The scenario of using rabbitmq
3. What are the advantages and disadvantages of RabbitMQ?
4. What is Message?
5. Why use rabbitmq
6. How to distribute the news?
7. How to ensure that the message is sent to RabbitMQ correctly? How to ensure that the receiver of the message consumes the message?
8. How are messages routed?
9. How to ensure that the message is not lost?
10. What transmission is the message based on?
11. How to ensure the sequence of messages
12. What is the difference between Kafka, ActiveMQ, RabbitMQ, and RocketMQ?
13. Fanout (broadcast distribution)?
14. How to ensure high availability?
15. Disadvantages of mq
16. How to ensure the reliable transmission of messages? what to do if the message is lost
17. How to avoid repeated message delivery or repeated consumption?
18. What is Message?
19. How to solve the problem of message queue delay and expiration? What should I do when the message queue is full? There are millions of messages that continue to backlog for several hours, how to solve it
20. RabbitMQ cluster
21. What is Connection?
22. Topic switcher (pattern matching)?
23. Exchange type?
24. Ideas for designing MQ
Seventeen, Dubbo interview questions
1. Why use Dubbo?
2. What is Dubbo?
3. What communication framework is used by default, and are there other options?
4. What is the difference between Dubbo and Spring Cloud?
5. What registration center is generally used? Is there another option?
6. What protocols does dubbo support, and which one is recommended?
7. What is the principle that the service provider can realize the failure kick?
8. What are the layers of Dubbo's overall architecture design?
9. How to solve the problem that the service call chain is too long?
10. Tell me about the core configuration?
11. What protocol does Dubbo recommend?
12. What serialization framework is used by default, and what else do you know?
13. Draw a flow chart of service registration and discovery?
14. How many solutions are there for Dubbo cluster fault tolerance?
15. Why does the service launch not affect the old version?
16. Dubbo service is downgraded, what should I do if it fails and retry?
17. What is the implementation principle of Dubbo Monitor?
18. What design patterns does Dubbo use?
19. How is the Dubbo configuration file loaded into Spring?
20. Is the service call blocked?
21. Does Dubbo support distributed transactions?
22. Can Dubbo cache the results?
18. MyBatis interview questions
1. What is Mybatis?
2. How many ways does MyBatis implement one-to-one? How does it work?
3. Disadvantages of MyBatis framework
4. There are several ways to implement one-to-many in MyBatis, how to operate?
5. What are the differences between MyBatis and Hibernate?
6. Does Mybatis support lazy loading? If supported, how is it implemented?
7. What should I do if the attribute name in the entity class is different from the field name in the table?
8. The first and second level caches of Mybatis:
9. Usually an Xml mapping file will write a Dao interface corresponding to it. Excuse me, what is the working principle of this Dao interface? Can the method in the Dao interface be overloaded when the parameters are different?
13. What are the requirements when using the mapper interface of MyBatis?
14. How to pass multiple parameters in mapper?
15. What are the ways to write Mapper?
16. Briefly describe the operating principle of Mybatis plug-ins and how to write a plug-in.
17. What are the programming steps of MyBatis?
Nineteen, ZooKeeper interview questions
1. What is Zookeeper ?
2. The data structure (tree) of zoo keeper ? Tell me about the distributed lock based on it? Master election based on it? Cluster management based on it? What are the usage scenarios of zoo keeper 's registration (watch) mechanism and polling mechanism?
3. What does ZooKeeper provide?
4. Tell me how to implement distributed locks with zoo keeper ?
5. ZAB protocol?
6. Zoo keeper synchronization process, write operation process, read operation process
7. What are the deployment methods of ZK? What are the roles in the cluster? The minimum number of machines required in the cluster
8. Realization of client registration Watcher
9. The server handles the realization of Watcher
10. Client callback Watcher
11. ACL permission control mechanism
12. Server role
13. Session management
14. Data synchronization
15. Server working status under Zoo keeper
16. How to deal with zk node downtime?
17. How does zoo keeper ensure the sequential consistency of transactions?
18. Why is there a Master in a distributed cluster?
19. The difference between zoo keeper load balancing and nginx load balancing
20. Chroot feature
21. How many machines are required for the cluster at least, and what are the cluster rules?
22. Does the cluster support dynamic addition of machines?
23. Is Zoo keeper 's watch notification to nodes permanent? Why not forever?
24. What are the Java clients of Zoo keeper ?
25. What is chubby? How do you compare it to zoo keeper ?
26. Talk about some commonly used commands of zoo keeper .
27. What is the connection and difference between ZAB and Paxos algorithm ?
28. Typical application scenarios of Zoo keeper
20. Data structure interview questions
1. Stack
A stack is a table that restricts insertion and deletion to only one location, which is the end of the table, called the top of the stack. It is Last In First Out (LIFO). There are only two basic operations on the stack: push (into the stack) and pop (out of the stack). The former is equivalent to inserting, and the latter is equivalent to deleting the last element.
2. Queue
4. Prefix tree
6. Hash Table
7、B-TREE
8. Bitmap
9. Linked list (Link)
10. What are the common features of stacks and queues?
11. What are the two storage structures commonly used by the stack?
12. What are the advantages of using a linked list to represent a linear list?
13. What is the purpose of adding head nodes?
14. In a computer, what is an algorithm ?
21. Algorithm interview questions
1. There are {1, 2, 3, 4, 5, 6, 7, 8, 9} in the data, please randomly shuffle the order and generate a new array (please implement it with code)
2. Given an array nums, write a function to move all 0s to the end of the array while maintaining the relative order of the nonzero elements.
3. How to solve the imbalance problem of sample categories?
4. In the process of neural network training, why does the gradient disappear? How to prevent it?
6. Bubble sorting algorithm , insertion sorting algorithm , quick sorting algorithm , Hill sorting algorithm , merge sorting algorithm
7. In K-Means or KNN, the Euclidean distance is usually used to represent the distance between the nearest data points, and sometimes the Manhattan distance is used to compare the difference between the two.
8. Parametric and non-parametric models
9. Generative model and discriminative model
10. Calculation of parameters and FLOPs in neural network
11. Bucket sorting algorithm , radix sorting algorithm , pruning algorithm , backtracking algorithm
12、AES
13、RSA
14、CRC
15. Shortest path algorithm
16. Minimum spanning tree algorithm
18. There are two baskets, namely A and B. Basket A contains eggs, and basket B contains apples. Please use object-oriented thinking to realize the exchange of items in the two baskets (please use code to implement)
19. Assuming today is March 1, 2015, Sunday, please calculate the day of the week after 13 months and 6 days, and the number of days from now (please use code to implement, please do not call API methods)
20、MD5
21. Write the code to judge whether an integer is a power of 2 (please implement the code, please do not call the API method)
22. Elasticsearch interview questions
1. How much do you know about elasticsearch? Tell me about your company's es cluster architecture, index data size, number of fragments, and some tuning methods.
2. What to do when there is too much elasticsearch index data, how to tune and deploy
3. Describe in detail the process of Elasticsearch indexing documents
4. What is the inverted index of elasticsearch
5. How does elasticsearch implement master election
6. Describe the Elasticsearch search process in detail?
7. When deploying Elasticsearch, what are the optimization methods for Linux settings
8. Among the nodes in Elasticsearch (for example, there are 20 in total), 10 of them choose a master, and the other 10 choose another master, what should I do?
9. What is the internal structure of lucence?
10. How does Elasticsearch realize the Master election?
11. Describe in detail the process of Elasticsearch indexing documents.
12. Describe in detail the process of updating and deleting documents in Elasticsearch.
13. When the client connects to the cluster, how does it select a specific node to execute the request?
14. Describe the process of Elasticsearch search in detail
15. In Elasticsearch, how do you find the corresponding inverted index based on a word?
16. When deploying Elasticsearch, what are the optimization methods for Linux settings?
17. Regarding GC, what should be paid attention to when using Elasticsearch?
18. How is spelling error correction implemented?
19. Describe in detail the process of Elasticsearch indexing documents.
20. How to monitor the Elasticsearch cluster status?
21. Introduce the overall technical architecture of your e-commerce search?
22. Tell us about your personalized search solution?
23. Do you understand dictionary trees?
24. How does Elasticsearch realize the aggregation of large data volumes (hundreds of millions)
23. Kafka interview questions
1. What is Kafka
2. Compression (GZIP or Snappy)
3. Segmentation of data files (sequential read and write, segment command, binary search )
4. Partition data files (offset, MessageSize, data)
5. Consumer Design
6. Batch sending
7、Consumer Group
8. How to get a list of topic topics
9. What is the command line of the producer and consumer?
10. Load balancing (partition will be evenly distributed to different brokers)
11. Is the consumer pushing or pulling?
12. What is the role of Zoo keeper for Kafka?
13. What are the two conditions for Kafka to judge whether a node is still alive?
14. Why do we need a message system, can mysql not meet the demand?
15. Talk about kafka's method of maintaining consumption status tracking
16. How does the consumer not automatically submit the offset, but submit it by the application?
17. There are three key differences between Kafka and traditional MQ messaging systems
18. Talk about the three mechanisms of Kafka's ack
19. How to solve the livelock problem caused by consumer failure?
20. Talk about master-slave synchronization:
24. Microservice interview questions
1. What are the advantages of microservice architecture?
2. What are the best practices for designing microservices?
3. What is the difference between monolithic, SOA and microservice architecture?
4. What are the characteristics of microservices?
5. How does the microservice architecture work?
6. What challenges do you face when using microservice architecture?
7. What are the advantages and disadvantages of microservice architecture?
8. What are the characteristics of microservices?
9. What is Domain Driven Design?
10. What are the main differences between SOA and Microservice Architecture?
11. Why is Domain Driven Design (DDD) needed?
12. What is coupling?
13. What is ubiquitous language?
14. What is cohesion?
15. What do you know about Spring Boot?
16. What is REST / RESTful and what is it used for?
17. What is Spring Boot's Actuator?
18. What is Spring Cloud?
19. What problems does Spring Cloud solve?
20. What is the use of using WebMvcTest annotations in Spring MVC application?
21. Can you give the main points about rest and microservices?
22. What do you know about Distributed Transaction?
23. What are different types of microservice testing?
24. What is a bounded context?
25. What is Idempotence and where is it used?
26. What is two-factor authentication?
27. What are the types of credentials for two-factor authentication?
28. What is the use of PACT in microservice architecture?
29. What is a client certificate?
25. Linux interview questions
1. What symbol is used to represent the absolute path? What is the current directory and the upper directory? What is the main catalog? What order is used to switch catalogs?
2. What command is used to check the ip address and interface information?
3. How to clear the screen? How to exit the current command? How to implement sleep? how to check when
4. What command is used to specify the command prompt?
5. Check the commands in the file
6. List several commonly used Linux commands
7. How to alias the command?
8. Create soft links (shortcuts) and hard links
9. What should you do when you need to bind a macro or key to a command?
10. What commands can be used to view the contents of a file?
11. Randomly write file commands? How to output a string with spaces, such as "hello world" to the screen?
12. Your system currently has many running tasks. Is there any way to remove all running processes without restarting the machine?
13. Which command is used to move files? Which order to rename?
14. Which command is used to copy files? What if it needs to be copied together with the folder? What if there is a prompt function?
15. How to view the contents of a large file page by page?
16. What kinds of wildcards can be used in commands under Linux? What do they mean?
17. What command is used to count the contents of a file? (line number, word count, byte count)
18. What is the use of the Grep command? How to ignore case? How to find lines that do not contain this string?
19. What are the states of processes in Linux? What symbols are used in the information displayed by ps?
20. How to view the summary and usage of a linux command? Suppose you happen to see a command you have never seen before in the /bin directory, how can you know what it does and how to use it?
21. How to view the current process? How to perform exit? How to check the current path?
22. What function does the Ls command perform? What parameters can be taken and what is the difference?
23. How do you usually check the logs?
24. Which file is in which folder is the terminal? Which command is in which folder is the black hole file?
25. Which command is used to delete files? What if you need to delete the directory and the files under the directory together? What command to use to delete empty folders?
26. How to make a command run in the background?
27. What command is used to create a directory? What command is used to create the file? What order do you use to copy files?
28. Which command can I use to check the disk space quota of my file system?
The above is the summary of the Java back-end development interview [25 technical topics]. Due to the limited space, there are only part of the interview questions for each topic. The following is a collection
