Meituan is on all sides, and has already taken an offer

This collection of classics mainly comes from the Internet (Nioke.com, blog sites, etc.), and I hope it will be helpful to my friends.

one side

How message queues ensure reliability
How message queues ensure message idempotency
Advantages and disadvantages of message queues
Why use b+ tree
The difference between a clustered index and a primary key, how do other engines do it
usual database code
explain parameter
What are the http message parameters?
Do the question, the linked list is output in parity order

Self introduction
What sorting algorithms are there?
Introduce the quicksort/heapsort/mergesort.
How should the indexes in the database be designed?
What are the situations in which indexes fail?
What submission method does the HTTP interface you use use?
Difference between GET/POST?
Besides GET/POST what else?
Basic principles of object orientation? Let's talk about dependency inversion in detail.
Introduce the strategy pattern and the observer pattern?
How to ensure the idempotency of user requests? Idempotency means that the user may submit three payment requests in a row and return the same result (successful payment), but the actual background is only executed once to maintain consistency.
Introduce the four waves of TCP?
Does the client close immediately after the fourth wave? What is the status?
Two large files, each with a url on each line, to find the duplicate urls in the two files.
In a large file, each line has an integer, how to find the 100th largest number?
In a large file, each line has an integer, how to find the median?
Basic data structure of redis?
How is zset implemented? What are the commands?
Algorithm problem force buckle 221. The largest square

Project-related (module division, project requirements, technical solutions, database design, table structure and relationship, role)
The key fields of the http protocol, such as the key fields of the request and response header information, and their meanings
http status code: 100,200,502,504
The difference between http and https, what problem is https for solving
Three-way handshake, four-time wave (detailed process + state change)
What may be the reason for the large number of close_waits, the solution, what tool is used to see that there is a problem with the network, etc.
What are the common collections in Java? Do you understand the initial capacity loading factor of List, Set and Map?
What are the ways of thread communication in Java, the general principle
What to do if MySQL encounters problems with poor performance, such as slow queries
Database optimization plan (index | sub-database sub-table)
What are the indexes, data structures, and principles of indexing
The principle of sub-database sub-table, talk about the scene (horizontal | vertical, hot data | cold data blabla)
Algorithm Question: Sum of Two Numbers

Self-introduction, project introduction, asked about the amount of data
Know about microservices? (Have you conducted research on your own projects to understand the tools and methods commonly used by companies at present)
Do you know about springcloud?
A machine can not meet the transportation needs, what should I do? A: Build more machines, Q: How do multiple machines work together?
Explain mapreduce
If there is a large file, TB level, and the numbers in the file are out of order, how to sort? How is mapreduce implemented?
Merge sort in the sorting process, please describe its process? time complexity
The difference between process and thread, when using Java, what is the difference between the concept of multithreading and the thread process in os? How are threads and processes in Java scheduled when they are actually used?
Multi-threaded synchronization mutex method? Answered the semaphore, asked how to implement it, answered pv operation, gave a specific scene, asked how to initialize the variable (equivalent to oral code)
What indexes are there? (mysql example)
What kind of tree structures are b-trees and b+ trees, and the query complexity? Is it a balanced binary tree?
Have you used redis? What exactly?
Hand tearing code: LRU algorithm; forward and reverse order traversal of binary tree