preface
This is my interview with Ali Java backend development. I’m not going to write the first few pages. I have been too busy recently + my health condition has not been good, so I didn’t make a timely summary. Because I have had too many interviews recently, I think they are almost the same. There have been 4 technical interviews and 1 HR interview.
The operating system
1. What is the inter-process communication? Explain in detail which way you have used in which scenario
2. Conditions for deadlock occurrence
3. How many states do threads have in Java? Detailed instructions
4. OS pipeline implementation, ask deep, can not remember the specific problem
5. Break it down and break it down
6. Differences between virtual addresses, logical addresses, linear addresses, and physical addresses
7. What is the difference between coroutines and threads and processes
network
1. Three handshakes four waves, three waves ok
2. The difference between OSI and TCP/IP (the first question is asking me which book network read to learn, I said TCP/IP details)
3. HTTP server service, now want to do a frequency control for the user dimension or interface dimension, suppose 100 a second, ask without changing the original interface service, how do you achieve
4. Related to network security, how to defend against CSRF attacks
5. I am familiar with various protocols, such as TCP, UDP, and ICMP
6. The difference between microservices and HTTP services, your understanding of both
The database
1. Have you ever encountered garbled characters in mysql? How did you solve it
2.Select * From table_name where filed_name ! Do you have any questions about the meaning of the SQL statement = NULL
3. The difference between where and having
4. Introduce the mysql database engine InnoDB and its four isolation levels
5. What index has been used and what should I pay attention to using this index
6. What problems will arise in the database and table of data, and how to solve them
T_score (varchar),team1_id(int),team2_id (int);
Id :xx,team1_name: China,team2_name: Japan,score:4:1
algorithm
1. If I give you a positive integer k, which may be large but not exceeding integer_max, and I give you a positive integer m (0-9), how many times does m occur between 1 and k? If I give you k=12 and m=1, then 1 occurs four times
2. A N order int matrix, the person starts from (0,0), can only go up or right, the value of the matrix is the score value of the coordinate, the score value can only be obtained once, ask the person from (0,0) to (n-1, n-1) and back, what is the maximum score value obtained by the round trip
redis
1. Five data types in Redis
2. Explain redisObjects and SDS
3. Why does the redis sort set use a hop table instead of red black tree
4. How do I resolve cache inconsistency
Redis persistence, aOF file write and file synchronization explain
6. What scenarios are redis persistence AOF and RDB respectively applicable to
7. Redis various data structures and time complexity of operations
8. According to the master-slave replication principle of Redis, it is possible that the write operation writes to the master and the read operation reads to the slave, so that the latest data cannot be read. However, if I want to ensure consistency, how can I solve this problem
kafka
1. The concept explanation, the producer/consumer/partition/topic/offset/broker
2. Why does Kafka have such a high throughput compared to other MQ? Have you thought about what scenarios Kafka is suitable for, or how you compare the different MQ products
3. Cap theory in Kafka high Availability, discuss your understanding
4. How does Kafka ensure that messages are not re-consumed
5. I want to save messages in Kafka to different data sources
conclusion
Java Core Learning Notes, “covering JVM, high concurrency, reflection, Spring principle, distribution, microservices, MySQL, data structures, etc.” Master these knowledge points, in the interview candidates can be dazzled many. Opportunities are reserved for those who are prepared. Only with sufficient preparation can you stand out among the candidates.