Slow query log rotation and expiration¶
This feature is a tech preview. Before using this feature in production, we recommend that you test restoring production from physical backups in your environment, and also use the alternative backup method for redundancy.
This feature was implemented in Percona Server for MySQL 8.0.27-18.
Percona has implemented two new variables, max_slowlog_size and max_slowlog_files to provide users with ability to control the slow query log disk usage. These variables have the same behavior as the max_binlog_size variable and the max_binlog_files variable used for controlling the binary log.
System variables¶
max_slowlog_size¶
| Option | Description |
|---|---|
| Command-line | Yes |
| Config file | Yes |
| Scope | Global |
| Dynamic | Yes |
| Data type | numeric |
| Default | 0 (unlimited) |
| Range | 0 - 1073741824 |
The server rotates the slow query log when the log’s size reaches this value. The default value is 0. If you limit the size and this feature is enabled, the server renames the slow query log file to slow_query_log_file.000001.
max_slowlog_files¶
| Option | Description |
|---|---|
| Command-line | Yes |
| Config file | Yes |
| Scope | Global |
| Dynamic | Yes |
| Data type | numeric |
| Default | 0 (unlimited) |
| Range | 0 - 102400 |
This variable limits the total amount of slow query log files and is used with max_slowlog_size.
The server creates and adds slow query logs until reaching the range’s upper value. When the upper value is reached, the server creates a new slow query log file with a higher sequence number and deletes the log file with the lowest sequence number maintaining the total amount defined in the range.
