{"id":14403,"date":"2024-01-09T02:24:23","date_gmt":"2024-01-09T09:24:23","guid":{"rendered":"https:\/\/www.mysqltutorial.org\/?page_id=14403"},"modified":"2024-01-09T07:34:17","modified_gmt":"2024-01-09T14:34:17","slug":"innodb_log_buffer_size","status":"publish","type":"page","link":"https:\/\/www.mysqltutorial.org\/mysql-administration\/innodb_log_buffer_size\/","title":{"rendered":"innodb_log_buffer_size: Configure InnoDB Log Buffer Size"},"content":{"rendered":"\n

Summary<\/strong>: In this tutorial, you will learn how to configure InnoDB log buffer size using the innodb_log_buffer_size<\/code> configuration variable.<\/p>\n\n\n\n

In InnoDB<\/a>, a log buffer is a memory structure that stores the data modification before being written to the log files on disk.<\/p>\n\n\n\n

An optimal size of the log buffer can improve performance by reducing the frequency of expensive I\/O operations.<\/p>\n\n\n\n

The size of the log buffer is controlled by the innodb_log_buffer_size<\/code> configuration variables.<\/p>\n\n\n\n

The default value of log buffer size is often suitable for most applications. However, if you have a write-intensive application, you may need to adjust the buffer size based on your server’s memory and application characteristics.<\/p>\n\n\n\n

To check whether you need to adjust the log buffer size, you can use the innodb_log_waits<\/code> status variable.<\/p>\n\n\n\n

The InnoDB Log Waits occur when a transaction<\/a> is unable to write to the log buffer because it’s full. The innodb_log_waits<\/code> variable stores the number of times such waits have occurred.<\/p>\n\n\n\n

If innodb_log_waits<\/code> variable is greater than zero, so you likely need to adjust the size of the log buffer.<\/p>\n\n\n\n

Checking InnoDB Log Waits<\/h2>\n\n\n\n

First, connect to the MySQL server<\/a>:<\/p>\n\n\n

mysql -u root -p<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
Second, check the innodb_log_waits<\/code> value using the following query:<\/p>\n\n\n
SHOW<\/span> GLOBAL<\/span> STATUS<\/span> LIKE<\/span> 'Innodb_log_waits'<\/span>;<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
+------------------+-------+<\/span>\n| Variable_name    | Value |\n+------------------+-------+<\/span>\n| Innodb_log_waits | 0     |\n+------------------+-------+<\/span>\n1 row in set<\/span> (0.00<\/span> sec)<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
The output shows zero indicating that the size of the log buffer size is sufficient. If you see a value greater than zero, then you need to set the log buffer size to a bigger value.<\/p>\n\n\n\n
Configure the InnoDB Log Buffer Size: innodb_log_buffer_size<\/h2>\n\n\n\n
First, open the MySQL configuration file<\/a> (my.ini<\/code> or my.cnf<\/code>) and set the value based on your systems’ available memory and workload requirements:<\/p>\n\n\n
innodb_log_buffer_size = 32M<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
In this example, we set the size of the log buffer to 32MB.<\/p>\n\n\n\n
Third, connect to the MySQL server<\/a>:<\/p>\n\n\n
mysql -u root -p<\/code><\/span><\/pre>\n\n\n
Finally, check the value of the global variable innodb_log_buffer_size<\/code>:<\/p>\n\n\n
SHOW<\/span> GLOBAL<\/span> VARIABLES<\/span> LIKE<\/span> 'innodb_log_buffer_size'<\/span>;<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
+------------------------+----------+\n| Variable_name          | Value    |\n+------------------------+----------+\n| innodb_log_buffer_size | 33554432<\/span> |\n+------------------------+----------+\n1<\/span> row in<\/span> set<\/span> (0.01 sec)<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
The buffer size is in bytes. You can convert it to MB as follows:<\/p>\n\n\n
SELECT<\/span> ROUND<\/span>(@@innodb_log_buffer_size<\/span> \/ 1024<\/span> \/ 1024<\/span>, 0<\/span>);<\/code><\/span>Code language:<\/span> CSS<\/span> (<\/span>css<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
+--------------------------------------------------+\n| ROUND(@@innodb_log_buffer_size \/ 1024<\/span> \/ 1024<\/span>, 0<\/span>) |\n+--------------------------------------------------+\n|                                               32<\/span> |\n+--------------------------------------------------+\n1<\/span> row in<\/span> set<\/span> (0.00 sec)<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
It is 32MB as we set in the configuration file.<\/p>\n\n\n\n
Summary<\/h2>\n\n\n\n
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  • Configure InnoDB log buffer size according to your system memory and the requirements of the applications using the innodb_log_buffer_size<\/code> variable.<\/li>\n<\/ul>\n
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Second, restart the MySQL server<\/a> for the changes to take effect.<\/p>\n\n\n\n