MySQL architecture
Preface
This environment is based on Centos 7.8 system to build MySQL-5.7.14 for
specific construction, please refer to MySQL-5.7.14 environment construction
Mysql is composed of SQL interface, parser, optimizer, cache, and storage engine.
MySQL architecture
Hierarchical interpretation
Connectors refers to the interaction with SQL in different languages.
Management Services & Utilities: System Management and Control Tool
Connection Pool: Connection Pool. Manage buffering user connections, thread processing and other needs that require buffering. Mainly do authentication, connection restriction, memory checking, etc.
SQL Interface: SQL interface, accepts the user's SQL command, and returns the result that the user needs to query. For example, select from is to call SQL lnterface
Parser: parser. When SQL commands are passed to the parser, they will be verified and parsed by the parser.
Optimizer: Query optimizer. The SQL statement will use the query optimizer to optimize the query before the query.
Cache and Buffer: query cache. If the query cache has a matching query result, the query statement can go directly to the query cache to fetch data.
Engine: storage engine. The storage engine is a specific subsystem dealing with files in MySql.
1. Connection layer
# 查看最大连接数
show variables like '%max_connections%';
Second, the SQL layer
# 查看缓存配置情况
show variables like '%query_cache%';
Three, plug-in storage engine
The earlier version defaults to the myisam storage engine, and the inodb engine is supported by default since version 8.0
Fourth, the file system layer & log layer
File system supported by MySQL
Red Hat system supports ext*, xfs and other
windows systems supported by NAT32, NTFS, etc.
Network file system services: NFS, etc
....