Many students want to enter a big factory, especially those who have just graduated and have a short working life. Don't have any fluke, and steadfastly solidify the foundation. This is your only correct posture on the road to a high salary .
Okay, let's not say much, just serve the main dish.
01 Mysql
1. Three paradigms of database and judgment, ER diagram
2. The difference between innodb and myisam storage engine
3. Index classification (primary key, unique index, full-text index, covering index, etc.), the principle of the leftmost prefix, which conditions cannot use the index
4. The difference between B tree and B+ tree, why use B+ tree for index
5. Clustered index and non-clustered index (using non-clustered index query process)
6. ACID of the transaction (atomicity, consistency, isolation, durability)
7. Transaction isolation level and their respective problems (dirty read, non-repeatable read, phantom read) and solutions (gap lock and MVCC)
8. Optimistic and pessimistic locks, row locks and table locks, shared locks and exclusive locks (how does inndob manually add shared and exclusive locks)
9. MVCC (increase two version numbers) and specific control of delete, update, and select
10. Deadlock determination principle and specific scenarios
11. Slow query and solutions (explain, slow query log, show profile, etc.)
12. The difference between drop, truncate, and delete
13. The order of execution of different elements of the query statement (where, jion, limit, group by, having, etc.)
14. mysql optimization, read-write separation, master-slave replication
15. Transaction recovery mechanism when the database crashes (REDO log and UNDO log)
02 Redis
1. How does Redis make high availability and clustering
2. Comparison of the advantages and disadvantages of Redis and Memcached
3.What are the data storage types of Redis?
4.What are the application scenarios of Redis?
5. Redis persistence method, and which one is used in the project
6. How to solve the Redis cache avalanche?
7. How to solve the double write consistency between Redis and MySQL?
8. How to solve Redis cache penetration?
03 Computer Network
1. OSI seven-layer protocol, TCP/IP four-layer protocol
2. The network equipment corresponding to each layer (router, switch, gateway, bridge, hub, etc.), the protocol corresponding to each layer
3. The CSMA/CD protocol of the data link layer may be used in the written test
4. IP address classification, subnet division (commonly used in written tests)
5. The difference between TCP and UDP
6. TCP three handshake and four wave, why three handshake, why four wave
7. The essence of TCP: stop waiting protocol, continuous ARQ protocol, sliding window, flow control, congestion control (slow start, congestion avoidance, fast retransmission, fast recovery)
8. HTTP Status Code
9. HTTP caching mechanism (a series of requests such as cache-control, Expires and corresponding header fields)
10. The difference between session and cookie, what to do after cookie is disabled
11. DNS resolution process
12. Ports of commonly used protocols
04 Data structure and algorithm
1. Array, linked list (one-way, two-way, double-ended), stack and queue, binary tree, red-black tree, hash table, heap (maximum and minimum)
2. Personal experience: There are more questions about stacks and queues, hash tables, linked lists, and binary trees, but fewer pictures
3. Search: binary search and its transformation
4. Binary tree: pre-order, middle-order, post-order traversal, printing in a prescribed manner, operations between two nodes (nearest common ancestor, distance) and other issues.
5. The largest heap and smallest heap: large-scale data to find the largest number and other issues, how to adjust the heap and other issues.
6. Stacks and queues: data structures often used as algorithmic questions
7. Eight sorts: 3 simple: bubbling, selection, insertion and optimization, 5 advanced: quick sort, merge sort, heap sort, hill sort, bucket sort (fast sort, merge, heap are very important)
8. Handwritten heap sort
9. Which algorithm should be chosen to sort Ali's more than 20,000 employees by age?
05 Linux
1. Common commands: user control, permission control, process control, system status query, etc.
2. What does the /etc/hosts file do?
3 Linux directory structure (especially /proc is very important)
4. linux file system structure and startup process)
5. Java server troubleshooting (OOM, high CPU, high load, class conflict)
6. How to view thread information of Java applications
7. How to analyze the Thread dump file (Runnable, lock, code stack, operating system thread ID correlation)
06 Operating System
1. A binary file runs to produce the result, what did the operating system do (this is a very comprehensive question)
2. Deadlock conditions and banker algorithm, resource allocation diagram, etc.
3. Inter-process communication method
4. Five IO modes of linux (understanding of blocking and non-blocking, synchronous and asynchronous)
5. The difference between linux select, poll and epoll
6. The difference between process and thread, kernel-level thread and user-level thread
7. Page replacement algorithm, especially lru
8. Process scheduling algorithm
9. linux interrupt response mechanism
10. Virtual memory mechanism
08 Java programming
1. Talk about the understanding of Synchronized keywords, class locks, method locks, and reentry locks
2. The principle of volatile
3. Java thread status and mutual conversion
4. Several ways of thread synchronization and communication between threads
5. What is the general implementation of ArrayList and LinkedList? The difference between them and their advantages and disadvantages?
6. HashMap implementation principle, how to ensure the thread safety of HashMap
7. What is the internal implementation of ReentrantLock?
8. What are the garbage collection mechanism of JVM and the collection algorithm?
9. When will JVM trigger YGC and when will it trigger FGC?
10. How to optimize JVM memory and how to troubleshoot memory leaks
11. What is the principle of IOC in Spring framework?
12. How to implement an aspect with Spring?
13. Four necessary conditions for deadlock?
14. Common design patterns, handwriting a singleton, JDK, and Spring principles which adopt design patterns.
15. The relationship and difference between multithreading and high concurrency
16. What are the common high concurrency scenarios, and what are the corresponding architecture design schemes?
17. Introduce what are the complete distributed middleware, their application scenarios and functions.
18. Double 11 spike event, your technical architecture design ideas.
Most of the answers to the above interview questions have been covered in the following 81 Java interview compulsory test sites. If you don't understand it thoroughly, it is strongly recommended to study it three times .
Required questions and answers
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