Tips ： When the article is finished , Directories can be generated automatically , How to generate it, please refer to the help document on the right

Synchronization data consistency problem

Requirements for master-slave synchronization ：

• The data of read library and write library are consistent ( Final agreement );
• Write data must be written to the write library ;
• To read data, you must go to the Reading Library ( not always );

1 Understand the master-slave delay problem

2 Cause of master-slave delay problem

Example of master-slave delay

3 How to reduce master-slave delay

How to solve the problem of consistency

Method 1： Asynchronous replication

Method 2： Semi-synchronous replication

Method 3： Group replication

Group replication technology , abbreviation MGR（MySQL Group Replication）

• Paxos After the algorithm was proposed, it was widely used as a distributed consistency algorithm , such as Apache Of ZooKeeper Is based on Paxos Realized .