Shulou(Shulou.com)05/31 Report--

This article shows you the principle and process of Mysql replication. The content is concise and easy to understand. It will definitely brighten your eyes. I hope you can get something through the detailed introduction of this article.

The replication principle and process of Mysql

(1) the basic principle of replication process, three threads and the relationship between them.

Mysql's built-in replication function is the basis for building large, high-performance applications. Distribute the data of Mysql to multiple systems. The mechanism of this distribution is to copy the data of one host of Mysql to another host (slave) and execute it again. During replication, one server acts as the master server, while one or more other servers act as the slave server. The primary server writes updates to the binary log file and maintains an index of the file to track the log cycle. These logs can record updates sent to the slave server. When a slave server connects to the master server, it informs the master server of the location of the last successful update read by the slave server in the log. Receive any updates that have occurred since then from the server, then block and wait for the primary server to notify the new update.

3 threads:

First, the slave starts a worker thread-the Icano thread. The iUnip O thread opens a normal connection on master and then starts binlog dump process. Binlog dump process reads events from master's binary log, and if it has caught up with master, it sleeps and waits for master to generate new events. The Icano thread writes these events to the relay log.

SQL slave thread (SQL from the thread) handles the last step of the process. The SQL thread reads events from the relay log and updates the slave's data to make it consistent with the data in the master. As long as the thread is consistent with the Ibank O thread, the relay log is usually in the cache of OS, so the overhead of the relay log is small.

In addition, there is a worker thread in master: like other Mysql connections, slave opening a connection in master causes master to start a thread. There is an important limitation to the replication process-replication is serialized on slave, which means that parallel update operations on master cannot operate in parallel on slave.

The above is the principle and process of Mysql replication. Have you learned any knowledge or skills? If you want to learn more skills or enrich your knowledge reserve, you are welcome to follow the industry information channel.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.