Restricting the number of binlog files

Maximum number of binlog files can now be restricted in Percona Server with max_binlog_files. When variable max_binlog_files is set to non-zero value, the server will remove the oldest binlog file(s) whenever their number exceeds the value of the variable.

This variable can be used with the existing max_binlog_size variable to limit the disk usage of the binlog files. If max_binlog_size is set to 1G and max_binlog_files to 20 this will limit the maximum size of the binlogs on disk to 20G. The actual size limit is not necessarily max_binlog_size * max_binlog_files. Server restart or FLUSH LOGS will make the server start a new log file and thus resulting in log files that are not fully written in these cases limit will be lower.

Version Specific Information

• 5.5.27-29.0: Variable max_binlog_files introduced.

System Variables

variable max_binlog_files

Version Info:

• 5.5.27-29.0 – Introduced.

Command Line:

Yes

Config File:

Yes

Scope:

Global

Dynamic:

Yes

Variable Type:

ULONG

Default Value:

0 (unlimited)

Range:

0-102400

Example

Number of the binlog files before setting this variable

$ ls -l mysql-bin.0* | wc -l
26

Variable max_binlog_files is set to 20:

max_binlog_files = 20

In order for new value to take effect FLUSH LOGS needs to be run. After that the number of binlog files is 20

$ ls -l mysql-bin.0* | wc -l
20