most important words
In 2021, I really hope that the industry can bloom in spring.
Last year, due to the impact of the epidemic, countless industries were affected. Under the cold winter of the Internet, many programmers were laid off, and the environment was particularly difficult.
After I was laid off by the company, I started looking for a job in a hurry. I hit a wall again and again, and completely wiped out my confidence. I suddenly felt that the interview was getting harder and harder.
So, I began to adjust my status and focused on cultivating technical knowledge. It seems that everything has started to improve, and finally I won the p7 post offer.
So, I want to share my learning experience and the interview experience summed up by interviewing dozens of Internet companies to my colleagues (Java programmers).
01 Common division of Redis interview questions (6 parts)
- Conceptual understanding of Redis
- Detailed explanation of the basic data structure of Redis
- Redis high concurrency problem strategy
- Redis cluster structure and design concept
- Redis persistence mechanism
- Redis application scenario design
- Redis Learning Roadmap (xmind)
Redis Learning Roadmap (xmind)
02 The interview questions involved are as follows
- What are the characteristics of Redis?
- Data types supported by Redis
- Why does Redis need to put all data in memory?
- What are the applicable scenarios of Redis?
- What are the common business scenarios of Redis?
- What are the differences between Mem*** and Redis?
- What are the advantages of Redis over mem***d?
- What are the commonly used commands of Redis?
- Why is Redis designed to be single-threaded?
- What is the maximum capacity that a value of type string can store?
- What is the maximum storage capacity of each data type in Redis?
- What are the persistence mechanisms of Redis? What is the difference?
- Please introduce the advantages and disadvantages of the two persistence mechanisms of RDB and AOF?
- What is cache penetration? How to deal with it?
- What is a cache avalanche? How to deal with it?
- What are the Java clients supported by Redis? Briefly describe the characteristics.
- What are the update strategies for the cache? What are the precautions for each?
- What is a distributed lock? what's the effect?
- What can distributed locks be implemented through?
- Introduce the matters needing attention in distributed lock implementation?
- How does Redis implement distributed locks?
- What are the common elimination algorithms?
- What are the Redis elimination strategies?
- What are the Redis cache invalidation strategies?
- How many ways are there for the persistence mechanism of Redis?
- Please introduce the advantages and disadvantages of the persistence mechanism RDB and AOF?
- Is Redis single-threaded?
- What is the Redis communication protocol? What are the characteristics?
- Please introduce the data type SortedSet (zset) of Redis and the underlying implementation mechanism?
- What is the maximum number of nodes in a Redis cluster?
- What is the master-slave replication model of Redis cluster?
- How does Redis do memory optimization?
- What are the commands related to Redis transactions? What is a Redis transaction? What is the principle?
- What are the points of attention for Redis transactions?
- Why doesn't Redis support rollback?
- Please introduce the Redis cluster implementation scheme
- Please introduce the common business usage scenarios of Redis?
- Will Redis Cluster lose write operations? Why?
- Please introduce Redis's Pipeline (pipeline) and usage scenarios
- Please explain how Redis batch commands are different from Pipeline?
- What is Redis slow query? Through what configuration?
- What is the experience of slow query repair in Redis? How to fix it?
- Please introduce the publish and subscribe function of Redis
- Please introduce several reasons that may cause Redis to block
- How to detect Redis blocking exceptions?
- What are the memory consumption categories of Redis? What command is used for memory statistics?
- Briefly introduce what are the memory management methods of Redis?
- How to set the memory limit of Redis? what's the effect?
- What is bigkey? What's the impact? How to discover bigkey?
- Please briefly describe the basic usage of Jedis?
- What are the advantages of the Jedis connection pool chaining method?
- What does the hot and cold data mean?
- What does cache hit ratio indicate? How to improve cache hit rate?
- How to optimize the performance of Redis service?
- How to implement local caching? Please describe how you know
- Please introduce Spring annotation caching
- If the data of the AOF file is abnormal, what should the Redis service do?
- What are the advantages and disadvantages of Redis' master-slave replication mode?
- What are the advantages and disadvantages of Redis sentinel mode?
- What are the Redis cluster architecture modes?
- How to set the maximum number of connections for Redis? View the maximum number of connections for Redis? View the current number of connections to Redis?
- What are the characteristics of the linked list data structure of Redis?
- Please introduce the underlying implementation of Redis' String type?
- What are the benefits of using SSD for the String type of Redis?
- Design a list of the top 50 products that display the most popular selling products of the day on the homepage of the trading website?
- … …
The answer analysis of the interview questions is too long, so I won't list them all here. They have been organized into PDF documents as shown below. Friends in need can get them at the end of the article!
Analysis of Redis Interview Questions
03 Finally, take a look at a Redis study note I compiled myself
- Why use redis / why use cache (high performance, high concurrency)
- Why use redis instead of map/guava for caching?
- Common data structures of redis and analysis of usage scenarios ( String, Hash, List, Set, Sorted Set )
- Redis memory elimination mechanism ( 2000w data in MySQL, only 20w data in Redis, how to ensure that the data in Redis is hot data? )
- Redis persistence mechanism ( how to ensure that data can be restored after redis hangs up and then restarts )
- Common Redis exceptions and solutions ( cache penetration, cache avalanche, cache warm-up, cache downgrade )
- Common application scenarios in distributed environments ( distributed locks, distributed auto-increment IDs )
- Redis cluster mode ( master-slave mode, sentinel mode, Cluster cluster mode )
- How to solve the problem of concurrent key competition in Redis?
- How to ensure data consistency when the cache and the database are double-written?
- … …
My Redis study notes
At last
After all, I have been working for so long. In addition to the first round of Tuhu, I have also interviewed many big factories, such as Ali, Ele.me, Meituan, and Didi. The interview process is not written in this article. . I will organize a detailed interview process and some details of the questions you want to know
Meituan Interview Experience
Byte interview experience
Rookie interview experience
Ant Financial interview experience
Vipshop interview experience
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Ant Financial Interview Experience
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Interview Experience
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Due to limited space, the pictures and texts cannot be issued in detail