Programmer Think

1 Introduction to multi-level cache architecture In any project, we have some frequent queries, and the frequent query data are basically the same. For example, in the project, we view user personal information, shopping Carnival query activity information. These function points are used frequently, and we generally need to deal with the ...

Common problems in redis development - cache penetration - cache avalanche - redis brain crack - cache breakdown preface In our daily development, we all use the database to store data. Because there is usually no high concurrency in general system tasks, it seems that there is no problem. However, once the demand for a large amount of ...

concept Master Slave replication refers to copying data from one Redis server to other Redis servers. The former is called master/leader and the latter is called slave/follower; Data replication is unidirectional and can only be from master node to Slave node. Master mainly writes, Slave mainly reads. Master-slave copy, read-write separation! ...

1, Background cache optimization idea The performance of a website is good or bad, and the impact of network IO and disk IO is relatively large. The purpose of introducing cache now is to improve the performance of the website. In fact, the essence is not to use the disk memory to reduce the disk IO to improve the performance. But have w ...

Redis overview Redis is a key value storage system (official website: http://redis.io ), is a distributed cache database Redis initial operation Start redis service Startup in docker environment (multiple containers need to be run to start docker environment): The # bottom layer of docker start redis01 is also started through redis serv ...

Overview of distributed locks Before understanding distributed locks, we should first know why distributed locks are used. Let's first understand the following cache exceptions Cache exception Cache penetration It refers to querying a certain nonexistent data. Because the cache does not hit, we will query the database, but the database doe ...

Detailed analysis of Mybatis cache 1, Cache cache The purpose of caching is to improve the efficiency of query and reduce the pressure on the database. MyBatis provides level 1 cache and level 2 cache, and reserves an interface for integrating third-party cache. All classes related to cache in MyBatis are in the cache package. There is a ...

What is circular dependency The creation of class a depends on class B, and the creation of class B depends on class A There are four simple cases DependencyDependency injection modeAre circular dependencies resolvedAB interdependence (cyclic dependency)setter method is used for injectionyesAB interdependence (cyclic dependency)All are inje ...

1, What is interface idempotency Idempotency is that the results of only multiple operations are consistent. Someone here may have questions. Q: why should the results of multiple operations be consistent? For example, when I query data, what I find out is the same every time. Even if I modify it, should it be the same every time? A: by mult ...

Redis implements the publish / subscribe function, and developers can quickly carry out scenario applications through this lightweight function. SUBSCRIBE,UNSUBSCRIBE and PUBLISH Realized Publish / subscribe messaging paradigm , this decoupling between publishers and subscribers can achieve greater scalability and more dynamic network topology. ...