How to realize MySQL underlying optimization: Optimization and performance improvement of log system

MySQL is one of the most popular relational database management systems currently. As the core component of the backend of websites and applications, its performance optimization is particularly critical. Among them, the log system is an important part of MySQL, and its performance has a great impact on the overall performance of the database. Therefore, this article will discuss in depth the optimization and performance improvement of the MySQL log system.

The role of the log system

In the MySQL database, the log system is mainly divided into 4 categories: error log, query log, binary log and slow query log. The error log is used to record errors and warning messages that occur during normal operation of the MySQL server, so that administrators can check and solve them in a timely manner; the query log is used to record all query requests and responses received by the MySQL server for query optimization and performance analysis; The binary log is used to record all changes to the MySQL database for data backup and recovery; the slow query log is used to record events such as query statement timeout or too long execution time to optimize queries.

Optimization scheme of MySQL log system

MySQL log system has four major optimization schemes:

1. Choose the appropriate log storage location

MySQL logs can be stored in multiple locations, such as the system log directory, MySQL data directory, etc. To improve performance, it is recommended to store all log files on separate physical disks. This can avoid log files from interfering with data reading and writing.

2. Coordinate the writing time of different log types

In the MySQL log system, different log types write at different times. For example, error logs and slow query logs are written very infrequently, while query logs and binary logs are written relatively frequently. Therefore, in order to avoid excessive I/O operations, it is recommended to set the query log and binary log writing time to the same time interval, which can be achieved by adjusting the parameters log_bin and log_slave_updates.

3. Set the log file size reasonably

When the log file is too large, MySQL will frequently switch files, which will increase disk I/O and CPU load and reduce the database performance. Therefore, it is important to set the log file size appropriately. For more frequent logs, you can set it to a smaller value. For example, binary logs and query logs can be set to 2-4MB, while error logs and slow query logs can be set to 10-20MB.

4. Use a log engine that supports concurrent writing

In MySQL, the type of log engine affects the performance of concurrent log writing. Currently commonly used logging engines include MyISAM and InnoDB. MyISAM locks write operations, so writes can only be serialized. InnoDB supports multi-threaded concurrent writing, which can improve writing performance. Therefore, in scenarios with high concurrent writing, it is recommended to use InnoDB as the log engine.

Specific code examples to implement the optimization plan

Specific code examples will be given below to facilitate readers' actual operation.

1. Store all log files on independent physical disks:

Modify the my.cnf configuration file and add log-error, log-bin and slow-query -Change the path where the log is located to an independent physical disk path.

[mysqld]
log-error=/var/lib/mysql/logs/error.log
log-bin=/var/lib/mysql/logs/bin.log
slow-query-log-file=/var/lib/mysql/logs/slowquery.log

2. Coordinate the writing time of different log types:

Modify my. cnf configuration file, set the writing time of log_bin and log_slave_updates to 1s.

[mysqld]
log-bin=/var/lib/mysql/logs/bin.log
log_slave_updates=1

3. Set the log file size:

Modify the my.cnf configuration file and set the sizes of binlog and slow_query_log to 2M and 10M respectively.

[mysqld]
log-bin=/var/lib/mysql/logs/binlog
bin-log-size=2M
slow-query-log-file=/var/ lib/mysql/logs/slowquery.log
slow-query-log-file-size=10M

4. Use InnoDB as the log engine:

Modify my. cnf configuration file, change the default MyISAM engine to InnoDB.

[mysqld]
default-storage-engine=InnoDB

Summary

The above are the optimization and performance improvement methods of the MySQL log system and specific code examples. In practical applications, it needs to be adjusted and optimized according to specific conditions. At the same time, it can also be combined with other optimization solutions, such as index optimization, cache optimization, etc., to jointly improve the performance and reliability of the database.

The above is the detailed content of How to realize MySQL underlying optimization: Optimization and performance improvement of log system. For more information, please follow other related articles on the PHP Chinese website!