Restricting the number of binlog files¶
Maximum number of binlog files can now be restricted in Percona Server for MySQL 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.
Example¶
Number of the binlog files before setting this variable
$ ls -l mysql-bin.0* | wc -l
The output could be the following:
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
The output could be the following:
20
Version Specific Information¶
-
Percona Server for MySQL 5.7.10-1: Variable max_binlog_files ported from Percona Server for MySQL 5.6.
-
Percona Server 5.7.23-23: Variable max_binlog_files is deprecated and replaced with binlog_space_limit.
System Variables¶
max_binlog_files¶
| Option | Description |
|---|---|
| Command-line | Yes |
| Config file | Yes |
| Scope | Global |
| Dynamic | Yes |
| Data type | ULONG |
| Default | 0 (unlimited) |
| Range | 0-102400 |
binlog_space_limit¶
| Option | Description |
|---|---|
| Command-line | Yes |
| Config file | Yes |
| Scope | Global |
| Dynamic | No |
| Data type | ULONG |
| Default | 0 (unlimited) |
| Range | 0-102400 |
This option places an upper limit on the total size in bytes of all binary logs. A value of 0 means
“no limit”. This is useful for a server host that has limited disk space.
When the limit is reached, oldest binary logs are purged until the total size is under the limit or only active log is remaining.
Note
You should not set --binlog-space-limit to less or equal than the value of --max-binlog-size because after the max-binlog-size limit will be reached, logs will be rotated and immediately pruned by binlog-space-limit.