The previous blog mainly talked about the deployment configuration of redis cluster, the construction of the ruby environment required by the redis.trib.rb tool, the creation of the redis.trib.rb tool, and the viewing of cluster-related information. For a review, please refer to https://www.cnblogs.com/qiuhom-1874/p/13442458.html ; Today we w ...
Posted by GB_001 on Mon, 23 May 2022 22:14:20 +0300
summary
https://baike.baidu.com/item/Redis/6549233?fr=aladdin Baidu Encyclopedia
Basic knowledge
redis has 16 databases by default, and the 0 database is used by default. You can use the * * select * * command to switch
Connected.
my:0>select 3 # Switch database
"OK"
my:3>dbsize # View DB size
"0"
my:3>
Other commands ...
Posted by manalnor on Mon, 23 May 2022 07:29:25 +0300
Idempotent problem
Definition of idempotency in Http/1.1: one and multiple requests for a resource should have the same result for the resource itself (except for problems such as network timeout). In other words, any number of executions will have the same impact on the resource itself as one execution
Under what circumstances is idempotent ...
Posted by aspekt9 on Sun, 22 May 2022 05:04:51 +0300
introduce
Intersection: an element that appears at least twice in all setsUnion: combine the elements of multiple sets and remove the duplicate elementsDifference set: an element that exists in the first set and does not exist in other sets
Related commands
commandexplainsinter key [key ...]Gets the intersection of all setssinterstore desiti ...
Posted by KoopaTroopa on Sun, 22 May 2022 02:45:39 +0300
Sentinel mode
(automatic election mode)
summary
The method of master-slave switching technology is: when the master server is down, a slave server needs to be manually switched to the master server, which requires manual intervention, which is laborious and laborious, and the service will not be available for a period of time. This is not a r ...
Posted by ron814 on Sat, 21 May 2022 18:52:19 +0300
hash type and operation
① Overview
The hash type in Redis can be understood as a map container with String Key and String Value, so the hash type is suitable for storing value object information. Such as Username, Password or Age. Even if there are only a few fields in the hash, its data only takes up a small amount of disk space. Each ha ...
Posted by daniel_grant on Sat, 21 May 2022 04:01:06 +0300
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1, Single node instance
The s ...
Posted by alex.hughson on Fri, 20 May 2022 17:24:46 +0300
Cache penetration
Problem description
There must be no cache and data that cannot be queried. Because the cache is written passively when it misses, and for the sake of fault tolerance, if the data cannot be found from the storage layer, it will not be written to the cache, which will cause the nonexistent data to be queried in the storage ...
Posted by scuzzo on Thu, 19 May 2022 21:57:24 +0300
preface
In some scenarios, multiple processes must monopolize and share resources in a mutually exclusive manner. At this time, distributed locking is the most direct and effective.
With the rapid development of technology, the increase of data scale and the increasing popularity of distributed systems, an application is often deployed on mul ...
Posted by laide234 on Thu, 19 May 2022 05:32:16 +0300
1, Preparatory work
The redis compressed package of 5.0.4 can be downloaded from the official website. linux environment
2, Unzip and install
1. Create 6 new folders to install redis directory The directory path is / root/tools/7001
[root@my 7001]# pwd
/root/tools/7001
[root@my 7001]# ls
redis-5.0.4.tar.gz
2. Unzip and install redis
ta ...
Posted by sarijit on Thu, 19 May 2022 00:34:17 +0300