500 interview questions
Today, I will share with you all the most frequently used interview question banks in mainstream companies. They are also the latest answers after the Java version is upgraded, which will save the interviewees many unnecessary detours. At the same time, a detailed interview analysis document has been done for each topic to ensure that readers at each stage can understand it. At the same time, this part of the interview document can also be provided to students in need for free, and you can view it if you need it. How to get at the end of the article!
MySQL
- Primary key super key candidate key foreign key
- Four characteristics and meanings of database transactions
- The role of the view, can the view be changed?
- The difference between drop, delete and truncate
- How the index works and its types
- Type of connection
- Database paradigm
- The idea of database optimization
- The difference between stored procedures and triggers
21 good and bad MySQL performance optimization
MySQL55 questions and answers
Redis
- What are the benefits of using Redis?
- What are the advantages of redis over memcached?
- Redis common performance problems and solutions
- There are 2000w data in MySQL, and only 20w data is stored in redis. How to ensure that the data in redis is hot data
- What are the differences between Memcache and Redis?
- What are the common performance problems of Redis and how to solve them?
- The most suitable scenario for redis
- Do you understand the synchronization mechanism of Redis?
- Have you used Redis cluster, what is the principle of cluster?
- How does the redis cluster ensure consistency?
The most complete Redis book
Analysis of database interview questions:
MongoDB
- What is MongoDB?
- What language is MongoDB written in?
- What are the advantages of MongoDB?
- What is a database?
- What is a collection?
- What is a document?
- MongoDB and relational database terminology comparison chart
- What is "mongod"?
- What are the "mongod" parameters?
- What is "mongo"?
- Which MongoDB command can switch databases?
- What is a non-relational database?
- What are the types of non-relational databases?
- Why use MOngoDB?
- In which scenarios is MongoDB used?
- What do namespaces in MongoDB mean?
- Which languages support MongoDB?
- How to create a new database in MongoDB?
- How to view the database list in MongoDB?
- What does sharding in MongoDB mean?
- How to check the connection using MongoDB?
- What is replication?
- How to insert a document in a collection in MongoDB?
- How to remove-a database in MongoDB?
- How to create a collection in MongoDB?
- How to view a created collection in MongoDB?
- How to delete a collection in MongoDB?
- Why use analyzer in MongoDB?
- Does MongoDB support primary key foreign key relationships?
- What data types does MongoDB support?
- Why use the "Code" data type in MongoDB?
- Why use the "Regular Expression" data type in MongoDB?
- Why use the "Object ID" data type in MongoDB?
- How to insert a document in the collection?
- What are the components of "ObjectID"?
- What is an index in MongoDb?
- How to add index?
- What are the alternative products for MongoDB?
- How to query the documents in the collection?
- What method can be used to format the output result?
- How to use "AND" or "OR" conditions to query the documents in the collection in a loop?
- How to update data in MongoDB?
- How to delete documents?
- How to sort in MongoDB?
- What is aggregation?
- What is a replica set in MongoDB?
- Mongodb storage characteristics and internal principles?
Mongodb interview questions analysis:
Zookeeper
- What is zookeeper?
- What does zookeeper provide?
- zookeeper file system
- Four types of znodes for zookeeper
- zookeeper notification mechanism
- What are the application scenarios of zookeeper?
- zk naming service
- zk configuration management service
- zk cluster management
- zk's distributed lock
- zk queue management
- zk data replication
- How zk works
- How does zk ensure the order consistency of things
- Server working status under zk cluster
- How does zk elect Leader?
- zk synchronization process
- Distributed notification and coordination
- zk session mechanism
Analysis of zookeeper interview questions
Ngnix
- Please explain what is Nginx?
- Please list some features of Nginx?
- Please enumerate the differences between Nginx and Apache?
- Please explain how Nginx handles HTTP requests.
- In Nginx, how to use an undefined server name to prevent requests from being processed?
- What are the advantages of using a "reverse proxy server"?
- Please list the best uses of Nginx server.
- Please explain what are the Master and Worker processes on the Nginx server?
- Please explain how you open Nginx through a port other than 80?
- Please explain whether it is possible to replace Nginx errors with 502 errors, 503?
- In Nginx, explain how to keep double slashes in URLs?
- Please explain what is the role of ngx_ http_ upstream_ module?
- Please explain what is the C10K problem and how it was solved later?
- Please state what the stub_status and sub_filter commands do?
- Explain whether Nginx supports compressing requests to upstream?
- Explain how to get the current time in Nginx?
- Explain the purpose of -s with Nginx server?
- Explain how to add modules on Nginx server?
- How do multiple work processes in nginx listen to the same port? How to deal with the problem of customer connections?
- How is the hot update of the nginx program done?
Nginx interview questions analysis
Nginx full solution
Concurrent programming:
- What is multithreaded concurrency and parallelism?
- What is the thread safety issue?
- What is the memory visibility issue of shared variables?
- What is atomic operation in Java?
- What is the CAS operation in Java and the realization principle of AtomicLong?
- What is Java instruction reordering?
- What is the memory semantics of the Synchronized keyword in Java?
- What is the memory semantics of the Volatile keyword in Java?
- What is false sharing, why does it occur, and how to avoid it?
- What are reentrant locks, optimistic locks, pessimistic locks, fair locks, unfair locks, exclusive locks, and shared locks?
- Tell me about the implementation principle of ThreadLocal?
- How does ThreadLocal act as a thread isolation method for variables?
- Talk about the implementation principle of InheritableThreadLocal?
- How does InheritableThreadLocal make up for the fact that ThreadLocal does not support inheritance?
- How is the internal implementation of CyclicBarrier different from CountDownLatch?
- How does the Random class of the random number generator use the CAS algorithm to ensure the uniqueness of the new seed under multithreading?
- How does ThreadLocalRandom use the principle of ThreadLocal to solve the limitations of Random?
- How to use ThreadLocal to implement request scope scope bean in Spring framework?
- The realization of the bottom layer of the lock in the concurrent package (understanding of AQS)?
- Talk about the principle of exclusive lock ReentrantLock?
- Talk about the principle of ReentrantReadWriteLock?
- Understanding the principle of StampedLock?
- Talk about the understanding of the principle of the non-blocking unbounded queue ConcurrentLinkedQueue based on the linked list?
- How does the ConcurrentLinkedQueue internally use CAS non-blocking algorithm to ensure the thread safety of multi-threaded enqueue and dequeue operations?
- The principle of LinkedBlockingQueue based on linked list.
Concurrent programming interview collection
JVM
- Java memory allocation?
- What is the structure of the Java heap?
- What is Perm Gen space in the heap?
- Briefly describe the changes in the memory area of each version?
- Talk about the role of each area?
- Is there a memory leak in Java, briefly?
- Java class loading process?
- Describe the principle mechanism of JVM loading Class files?
- What is a class loader?
- What are the class loaders?
- What is the tomcat class loading mechanism?
- The class loader parent delegation model mechanism?
- What is GC? Why is GC?
- Briefly describe the Java garbage collection mechanism?
- How to judge whether an object is alive?
- The advantages and principles of garbage collection, and consider 2 types of recycling mechanisms?
- What is the basic principle of the garbage collector?
- Can the garbage collector reclaim memory immediately? Is there any way to proactively notify the virtual machine for garbage collection?
- Deep copy and shallow copy?
- What will System.gc() and Runtime.gc() do?
- If the object reference is set to null, will the garbage collector immediately release the memory occupied by the object?
- What is distributed garbage collection (DGC)? How does it work?
JVM interview analysis Daquan
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Spring
- Why do we need a proxy model?
- Talk about the advantages and bottlenecks of the static proxy model?
- Understanding of the realization principle of Java interface proxy mode?
- How to implement dynamic proxy using Java reflection?
- The designated enhancement of the Java interface proxy mode?
- Talk about the implementation of enhanced dynamic proxy for Cglib class?
- What is point cut, advice, and join point?
- What is the difference between join point and point cut?
- How to understand the aspects of aspect-oriented programming?
- Talk about the understanding of SpringAOP Weaving?
- Talk about the understanding of SpringAOP Introduction (introduction)?
- Explain the simple comparison between OOP and AOP?
- Explain the principle and difference between JDK dynamic proxy and CGLIB proxy?
- Explain the implementation principle of Schema-based AOP in the Spring framework?
- Explain how to implement transaction management based on AOP in the Spring framework?
- Talk about the understanding of the design idea of inversion of control?
- How to understand Spring IOC container?
Spring interview
Cache
- What are the redis data structures?
- Redis cache penetration, cache avalanche?
- How to use Redis to implement distributed locks?
- How to solve the problem of concurrent competition in Redis?
- Several methods of Redis persistence, what are the advantages and disadvantages, and how to achieve it?
- Redis's cache invalidation strategy?
- Redis cluster, high availability, principle?
- Redis cache fragmentation?
- Redis's data elimination strategy?
- Redis queue application scenario?
- Distributed usage scenario (storage session)?
network programming
- TCP connection and disconnection process?
- The interactive process of HTTP protocol, the difference between HTTP and HTTPS, the interactive process of SSL?
- What is the use of TCP's sliding window protocol?
- What are the methods of HTTP protocol?
- The basic process of Socket interaction?
- Talk about the tcp protocol (connection establishment process, slow start, sliding window, seven-layer model)?
- Webservice protocol (wsdl/soap format, the difference with restt protocol)?
- Talk about the Netty threading model, what is zero copy?
- TCP three handshake, four wave hands?
- DNS resolution process?
- How does TCP ensure reliable data transmission?
distributed
- What is the CAP theorem?
- Talk about CAP theory and BASE theory?
- What is final consistency? How to achieve final consistency?
- What is a consistent hash?
- Talk about distributed transactions?
- How to implement distributed locks?
- How to implement distributed session?
- How to ensure the consistency of the message?
- Understanding of load balancing?
- Forward proxy and reverse proxy?
- How does CDN implement?
- How to improve the QPS and throughput of the system?
- The underlying realization principle and mechanism of Dubbo?
- Describe the detailed process of a service from being published to being consumed?
- How to do service governance in distributed systems?
- How does message middleware solve the problem of message loss?
- How to deal with the failure of Dubbo service request?
- Understanding of distributed transactions?
- How to achieve load balancing and what algorithms can be implemented?
- What is the purpose of Zookeeper and the principle of election?
- Talk about the vertical split and horizontal split of data?
Partial data screenshot:
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How to obtain the information?
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