Cache architecture technology: Redis+MongDB, a must-hop for Ali P7 interview

A few days ago, a little brother came to me crying and squeezed his head into Alibaba. Three rounds of technology fell on the cache technology (Redis+MongDB) . After listening to the heartfelt words of my little brother, this...Cache architecture technology: Redis+MongDB, isn't it a pit that Ali P7 interviews must jump? If you can’t jump over, you’ll have to say godbye, "waiting for death" in the pit... and then... I’m thinking about myself every day, and suddenly I find that I don’t seem to have a good grasp of it, so I have to go home well." Make one make up".

 

After three days and three nights, I collected information related to the cache architecture: Redis+MongDB interviews, actual combat and other notes. After finishing the work, I feel pretty good. Today I will take out a treasure~~100% free to share with you

Let's talk about Redis first

Like the basic introduction to Redis, it is enough to master the knowledge points listed in the figure below.

Getting started with Redis basics

If you are advanced, you have to work harder. If you don't understand things like affairs, master-slave replication, sentries, clusters, etc., you can't get up.

Redis advanced advanced

Looking at the actual combat of Meituan's billion-level traffic Redis, Redis distributed locks, sessions, cache and database consistency issues, cache avalanches, etc. are all top technical points, which must be mastered and not discussed.

100 million traffic Redis combat

After reading these technical points, I will now test some of your Redis interview questions (get ready, take the trick):

1. Why use redis? /Why use cache?
2. Why use redis instead of map/guava for caching?
3. How to ensure data consistency between the cache and the database when it is double-written?
4. Redis common data structure and usage scenario analysis? (String/Hash/List/Set/Sorted Set)
5. How does redis set the expiration time?
6. Redis memory elimination mechanism (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?
7. What are the methods of Redis persistence and how to choose? (How to ensure that the data can be restored after redis hangs and restarts?)
8. redis affairs?
9. Common Redis exceptions and solutions? (Cache penetration/cache avalanche/cache warm-up/cache degradation)
10. Common application scenarios in a distributed environment? (Distributed lock/distributed self-increasing ID)
11. Redis cluster mode? (Master-Slave Mode/Sentinel Mode/Cluster Cluster Mode)
12. How to solve the key problem of concurrent competition in Redis?

 

If you can’t catch it, please see the screenshot of the answer below (there are a lot of analysis, but the interception is not complete, you can provide a complete answer analysis original):

 

 

To continue, Redis must have 70 questions (concept + data structure and instructions + high concurrency processing strategy + cluster + cache management and persistence mechanism + application scenario design) answers have been sorted out

• Part 1: Conceptual understanding of Redis
• 1. What is Redis?
• 2. What are the characteristics of Redis?
• 3. What are the differences between Memcache and Redis?　　
• 4. What are the advantages of Redis over Memcached?
• 5. How to implement local caching? Please describe the way you know
• 6. What is the Redis communication protocol? What are the characteristics?

• Part 2: Redis data structure and instructions
• 1. Data types supported by Redis
• 2. What are the commonly used commands in Redis?
• 3. What is the maximum storage capacity for a string type value?
• 4. What is the maximum storage capacity of each data type in Redis?
• 5. Please introduce the Redis data type SortedSet (zset) and the underlying implementation mechanism?
• 6. What are the Redis transaction related commands?
• 7. What is Redis transaction? What is the principle?
• 8. What are the points to note about Redis transactions?
• 9. Why doesn't Redis support rollback?
• 10. Please introduce Redis's Pipeline (pipeline) and usage scenarios
• 11. Please explain the difference between Redis batch commands and Pipeline?
• 12. Please introduce Redis's publish and subscribe function
• 13. What are the characteristics of Redis's linked list data structure?
• 14. Please introduce the underlying implementation of Redis's String type?
• 15. What are the benefits of using SSD for Redis String type?
• 16. What are the commands for setting the lifetime and expiration time of the key?

• Part 3: Redis High Concurrency Processing Strategy
• 1. Why does Redis need to put all data in memory?
• 2. Is Redis single-threaded?
• 3. Why is Redis designed to be single-threaded?
• 4. What is cache penetration? How to deal with it?
• 5. What is a cache avalanche? How to deal with it?
• 6. How many cache update strategies are there? What are the precautions?
• 7. Please introduce several reasons that may cause Redis to block
• 8. How to find abnormal blocking of Redis?

• Part 4: Redis cluster structure and design concept
• 1. What are the Redis cluster architecture modes?
• 2. What is the maximum number of nodes in a Redis cluster?
• 3. What is the master-slave replication model of Redis cluster?
• 4. Please introduce the Redis cluster implementation scheme
• 5. Will there be write operations lost in the Redis cluster? why
• 6. What is Redis slow query? Through what configuration?
• 7. What are the experience of slow query repair in Redis? How to fix it?
• 8. How to optimize the performance of Redis service?
• 9. What are the advantages and disadvantages of Redis's master-slave replication model?
• 10. What are the advantages and disadvantages of Redis sentinel mode?
• 11. How to set the maximum number of connections for Redis? Check the maximum number of Redis connections? View Redis current
• 12. Introduce some common security settings for Redis?

• Part 5: Redis cache management and persistence mechanism
• 1. What are the Redis persistence mechanisms?
• 2. What are the differences between Redis persistence mechanism AOF and RDB?
• 3. Please introduce the advantages and disadvantages of RDB persistence mechanism
• 4. Please introduce the advantages and disadvantages of AOF persistence mechanism
• 5. If the data of the AOF file is abnormal, what should the Redis service do?
• 6. What are the common elimination algorithms?
• 7. What are the Redis elimination strategies?
• 8. What are the Redis cache invalidation strategies?
• 9. How does Redis optimize memory?
• 10. What is bigkey? What is the impact?
• 11. How to find bigkey?
• 12. What are the memory consumption classifications of Redis? What command is used for memory statistics?
• 13. What are the memory management methods of Redis?
• 14. How to set the upper limit of Redis memory? what's the effect?
• 15. What should I do if Redis reports insufficient memory?

• Part VI: Redis application scenario design
• 1. What are the applicable scenarios for Redis?
• 2. What are the commonly used business scenarios for Redis?
• 3. What Java clients does Redis support? Briefly explain the characteristics.
• 4. Please briefly describe the basic usage of Jedis?
• 5. What are the advantages of Jedis connection pool link method?
• 6. What is a distributed lock? what's the effect?
• 7. What can be achieved by distributed locks?
• 8. Introduce the matters needing attention when implementing distributed locks?
• 9. How does Redis implement distributed locks?
• 10. What does the cache hit rate mean?
• 11. How to improve cache hit rate?
• 12. Please introduce Spring annotation caching

After talking about the interview, it’s time to get started and see the actual Redis combat. For example, the translated "Redis In Action" below is a good reference material.

 

The book is divided into three parts: introduction, core concepts, and advanced content.

• The first part introduces Redis, explains the basic use of Redis, the five data structures it has, and the commands to operate these five data structures, and explains how to use Redis to build article aggregation websites, cookies, shopping carts, A series of programs such as web page caching and database row caching.

 

• The second part introduces Redis commands in more detail, and shows how to use Redis to build more complex auxiliary tools and applications, and finally shows how to use Redis to build a simple social website.

 

• The third part introduces some of the problems that Redis users often encounter, explaining methods to reduce Redis memory usage, methods to extend Redis performance, and methods to use Lua language for script programming.

 

Redis said so much, don’t forget MongDB

 

From entry to advanced to actual combat, I have listed all the above technical points for MongDB. If you master it, you will be a big man~

In order to help you quickly become a big cow, I think you can't miss the two notes pdf of "Using MongoDB-Quick Start" + "Using MongoDB-Cluster Security" .

The first book: MongoDB quick start

1 MongoDB related concepts

• 1.1 Business application scenarios
• 1.2 Introduction to MongoDB
• 1.3 Architecture
• 1.4 Data Model
• 1.5 Features of MongoDB

2 Stand-alone deployment

• 2.1 Installation start in Windows system
• 2.2 Shell connection (mongo command)
• 2.3 Compass-graphical interface client
• 2.4 Installation, startup and connection in Linux system

3 Basic common commands

• 3.1 Case requirements
• 3.2 Database operation
• 3.3 Set operations
• 3.4 Document basic CRUD
• 3.5 Paging query of documents
• 3.6 More queries for documents

4 Index-Index

• 4.1 Overview
• 4.2 Types of indexes
• 4.3 Index management operations
• 4.4 Use of Index

5 Article comments

• 5.1 Demand analysis
• 5.2 Table structure analysis
• 5.3 Technical selection
• 5.4 Construction of article microservice module
• 5.5 Writing the article comment entity class
• 5.6 Basic addition, deletion, modification and checking of article comments
• 5.7 Query the pagination list of article comments based on the superior ID
• 5.8 MongoTemplate implements comments and likes

Get started quickly with MongoDB

Get started quickly with MongoDB

The second book: MongoDB cluster and security

1 Replica Sets-Replica Sets

• 1.1 Introduction
• 1.2 The three roles of the replica set
• 1.3 Replica set architecture goals
• 1.4 Creation of replica set
• 1.5 Data read and write operations of the replica set
• 1.6 Principles for the election of master nodes
• 1.7 Failure test
• 1.8 Compass connection replica set
• 1.9 SpringDataMongoDB connection replica set

2 Sharded Cluster-Sharded Cluster

• 2.1 Fragmentation concept
• 2.2 Components included in a sharded cluster
• 2.3 Sharded cluster architecture goals
• 2.4 Creation of replica set of shard (storage) node
• 2.5 Creation of configuration node replica set
• 2.6 Creation and operation of routing nodes
• 2.7 Compass connect to sharded cluster
• 2.8 SpringDataMongDB connects to the sharded cluster
• 2.9 Clear all node data (spare)

3 Safety certification

• 3.1 Introduction to MongoDB user and role permissions
• 3.2 Single instance environment
• 3.3 Replica set environment
• 3.4 Sharded cluster environment (extended)

MongoDB cluster and security

MongoDB cluster and security

to sum up

Space is limited! Space is limited! Regarding cache architecture technology: Redis+MongDB, let’s talk about it here...

All the relevant notes and materials introduced by the editor above have been organized into a book, whether it is Redis interview + Redis actual combat pdf , or MongDB quick start + MongDB cluster security and other handwritten pdf notes , it is easy to want to prostitute! !

——If you get it, then click like and forward to support a wave!

——It is not easy to organize, 100% free to share!

——I wish a bright future, continuous offers, study hard, and make progress every day!