Mysql DBA Advanced Operations Learning Note-MYSQL Database Multi-instance Introduction

5.1 MySQL Multi-instance Introduction

5.1.1 What is MySQL multi-instance?

To put it simply, multiple different service ports (such as 3306,3307) are opened on a single machine, running multiple MySQL service processes that provide their own services through different sockets that listen to different service ports.
These MySQL multiple instances share a set of MySQL installers that use different (and also the same) MY.CNF configuration files, startup programs, and data files. What we learned today is a common set of installers that use different configuration files, different startup programs, and different data files. In the provision of services, multi-instance MySQL logically appears to be separate, multiple instances of itself is based on the configuration file corresponding to the setting value, to obtain the relevant hardware resources of the server how much.
To make an image analogy, MySQL multi-instance equivalent to the house of multiple bedrooms, each instance can be regarded as a bedroom, the entire server is a house, server hardware resources can be regarded as the house of the bathroom, kitchen is the public resources of the house. It's like being in a house in the north, so be sure to share the resources. In fact, many services can be many instances such as Nginx,apache,redias.

5.1.2 MySQL multiple instances of the role and problems.

5.1.2.1 Efficient use of server resources

When a single server resource is left, you can take advantage of the remaining resources to provide more services. The average server resource occupancy should be 60%-70%.

5.1.2.2 Conserve server resources

When the company's funds are more tense, but the database needs to separate as far as possible to provide services, and the need for master-slave synchronization technology when more than a good example.

The problem of mutual preemption of 5.1.2.3 resources

When an instance is high or slow, the entire instance consumes more memory, CPU, and disk IO resources from the entire server, causing the quality of the services on the server to degrade, which is equivalent to living in a different bedroom in a house, getting up to work in the morning, brushing your teeth, washing your face and so on. So the bathroom will be occupied for a long time, other people have to wait for the same reason.

Mysql DBA Advanced Operations Learning Note-MYSQL Database Multi-instance Introduction