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How to use caffeine_redis to customize the second level cache

The question is based on the requirements raised. I think there are two main issues: how to ensure data consistency because of the local cache. When the data of one node changes, how does the data of other nodes become invalid? The data is incorrect and needs to be resynchronized. How to invalidate the cache? Flowchart The next step is to cooperate with the product and other developers to draw a flowchart, as follows: Use a configuration table to record whether caching is needed and whether caching is enabled to achieve cache invalidation when notified. Because the project requirements are general, even if the message is lost, there will not be much impact, so we finally chose the subscription and publishing functions in redis to notify other nodes of invalid local cache. The development issues are clear, and the flow chart is also clear. Then get ready to start writing bugs. The overall idea is to

May 27, 2023 am 10:08 AM

redis

How to build a redis cluster under centos

Necessary tools: redis-3.0.0.tarredis-3.0.0.gem (ruby and redis interface) Analysis: First, the number of clusters requires a base. Here is a simple redis cluster (6 redis instances for clustering). Operates on one server, so only 6 different port numbers are required. They are: 7001, 7002, 7003, 7004, 7005, 7006. Steps: 1. Upload redis-3.0.0.tar to the server (specify your own software directory) and decompress redis-3.0.0.tar. 2. Install the c language environment (after installing centos, it comes with the c language environment) yuminst

May 27, 2023 am 10:04 AM

redisCentOS

How to synchronize MySQL data to Redis cache

1Mysql checks the data and then writes it to Redis synchronously. Disadvantage 1: It will cause delay to the interface, because synchronous writing to redis itself has delays and requires retrying. If redis writing fails, it needs to be retried. Then It's even more time consuming. Disadvantage 2: No decoupling. If redis crashes, the thread will be blocked directly. Disadvantage 3: If someone is the database, it cannot be synchronized unless the corresponding Redis is manually deleted, but there is also a time difference in the process of deleting Redis. 2Mysql check After completing the data, send MQ to synchronize Redis in the consumer thread. Disadvantage 1: There are more layers of MQ, which means there is a high probability of causing synchronization delay problems. Disadvantage 2: Prevent the availability of MQ. Disadvantage 3: If

May 27, 2023 am 09:08 AM

MySQLredis

How SpringBoot integrates Spring Cache to implement Redis caching

1. Introduction SpringCache is a framework that implements annotation-based caching functions. You only need to simply add an annotation to implement the caching function. SpringCache provides a layer of abstraction, and the bottom layer can switch different cache implementations. Specifically, different caching technologies are unified through the CacheManager interface. CacheManager is an abstract interface for various caching technologies provided by Spring. This is the default caching technology and is cached in Map. This also means that when the service hangs up, the cached data will be gone. Different caching technologies need to implement different CacheManagerCacheManager description EhCacheCach

May 27, 2023 am 08:47 AM

redisSpringBootspringcache

How to implement a universal Redis addition, deletion, modification and query script

1. Think about what duplicate codes there are?If it is just for simple addition, deletion, modification and query, then you only need to tell me which class needs to be serialized and deserialized, and tell me what the prefix of the key is, isn't that enough? As for the expiration time, we can ignore it this time. If we need to add the expiration time, it is not a difficult thing. Then we think about it for a while and use generics in Java to get the following basic class: 2 .Basic service class publicclassBasicDataRedisService{/***RediskeyprefixString*key prefix in Redis*/privateStringprefixString;p

May 27, 2023 am 08:28 AM

redis

How to use redis to create a flash sale support demo

Use redis to deduct inventory for flash sales, limiting each account to only one snap-up. This simple demo uses three basic types: string, hash, and list. Use int values of string type to store the remaining inventory, and reduce it after the snap-up is successful. 1. Use hash to store the ID of the member who has been "sold out" (to ensure the uniqueness of the user ID as a field). Note: The uid corresponding to the hash field may not necessarily be a successful snap up. Use a list to save the ID of a member who has actually been snapped up successfully. When I first wrote the list as a queue for subsequent processing of orders, I tried to use the bitmap of string to save whether the member had successfully purchased, but

May 27, 2023 am 08:22 AM

redisdemo

What are the persistence solutions in redis?

What are the persistence methods? What's the difference? Redis persistence solutions are divided into two types: RDB and AOF. RDBRDB persistence can be executed manually or periodically according to the configuration. Its function is to save the database status at a certain point in time to an RDB file. The RDB file is a compressed binary file through which the database status at a certain moment can be restored. state. Since the RDB file is saved on the hard disk, even if redis crashes or exits, as long as the RDB file exists, it can be used to restore the database state. RDB files can be generated through SAVE or BGSAVE. The SAVE command will block the redis process until the RDB file is generated. During the process blocking, re

May 27, 2023 am 08:08 AM

redis

How to quickly deploy Redis with Docker

1 Find the redis image on DockerHub [root@wugenqiangredis] #dockersearchredis2pull image [root@wugenqiang~] #dockerpullredis:3.2 Here we pull the official image, labeled 3.23 Run image [root@wugenqiangredis] #dockerrun-d--nameredis -server-p6379:6379-v$PWD/data:/data-dredis:3.2--requirepass"123456"

May 27, 2023 am 08:07 AM

Dockerredis

What are the persistence methods of Redis?

Why is persistence needed? Normally, all redis data is stored in memory. Once the database fails and is restarted, all data will be lost. Even in rediscluster or redissentinel mode, the recovery of master-slave synchronization data still takes some time. The persistence function can effectively avoid data loss caused by process exit. Data can be restored by using the previously persisted files during the next restart. After Redis persistence is turned on, the data will be stored on the disk, and the time it takes for the database to perform incremental synchronization is much less than full synchronization. Data recovery from failures plays a very important role in a production environment! There are two options for Redis data persistence. There are two options for Redis persistence.

May 27, 2023 am 08:02 AM

redis

How to use docker to start redis and access it remotely on Linux

1. Install docker on centos71. Install some necessary system tools yuminstall-yyum-utilsdevice-mapper-persistent-datalvm22. Install docker’s yum source yum-config-manager--add-repohttp://download.docker.com/linux /centos/docker-ce.repo#Central warehouse yum-config-manager--add-repohttp://mirrors.aliyun.com/docker-ce

May 27, 2023 am 08:01 AM

DockerLinuxredis

How to implement scheduled tasks in php redis

How to implement scheduled tasks in phpredis: 1. Modify the content of the configuration file redis.conf to "notify-keyspace-events"Ex""; 2. Restart the redis service; 3. Pass "object(Redis)#1(0){}string (22) "__keyevent@*__:expired" string (22) "__keyevent@0__:expire..." Just implement the scheduled task. PHP+redis implements the scheduled task and modify the configuration file redis.conf; notify-ke

May 26, 2023 pm 11:57 PM

PHPredis

How to use lazy deletion Lazy free in Redis

When Lazyfreekey expires using lazy deletion or the DEL delete command is used, Redis will not only remove the object from the global hash table, but also release the memory allocated by the object. When bigkey is encountered, releasing memory will cause the main thread to block. To this end, Redis 4.0 introduced the UNLINK command to put the object memory release operation into the bio background thread for execution. This effectively reduces main thread blocking. Redis6.0 goes a step further and introduces Lazy-free related configurations. When the configuration is enabled, the "release object" operation will be "executed asynchronously" within the key expiration and DEL commands. voiddelCommand(client*c){delGenericC

May 26, 2023 pm 11:37 PM

redis

How to build a stand-alone Redis cache service

1. Install gcc[root@localhost~]#yuminstallgcc Loaded plug-in: fastestmirror,langpacksbase|3.6kB00:00:00Loadingmirrorspeedsfromcachedhostfile*base: Resolving dependencies-->Checking transactions--->Software package gcc.x86_64.0.4 .8.5-16.el7 will be upgraded ---> Package gcc.x86_64.0.4.8.5-44.el7 will be updated --> Processing dependency libgomp=4.

May 26, 2023 pm 11:26 PM

redis

What will happen if Redis memory is too large?

1. When the main database is down, let’s first look at the disaster recovery process when the main database is down: As shown below, when the main database is down, our most common disaster recovery strategy is “cutting off the master”. Specifically, it selects a slave library from the remaining slave libraries of the cluster and upgrades it to the master library. After the slave library is upgraded to the master library, the remaining slave libraries are mounted under it to become its slave library, and finally the entire master-slave database is restored. Cluster structure. The above is a complete disaster recovery process, and the most costly process is the remounting of the slave library, not the switching of the main library. This is because redis cannot continue to synchronize data from the new main database after the main database changes based on synchronization points like mysql and mongodb. In the redis cluster, once the slave database changes master, Redis's approach is to clear the slave database that replaced the master database and then complete the synchronization from the new master database.

May 26, 2023 pm 11:19 PM

redis