mysql> INSTALL PLUGIN maxdiskusage SONAME 'maxdiskusage.so';
mysql> SET GLOBAL maxdiskusage_minfree=1000;
mysql> SET GLOBAL maxdiskusage_monitor_fs='/var/lib/mysql';
mysql> SET GLOBAL maxdiskusage_action='WARN';
With WARN:
mysql> INSERT INTO t1() VALUES();
Query OK, 1 row affected, 1 warning (0.00 sec)
mysql> SHOW WARNINGS;
+---------+------+------------------------------------------+
| Level | Code | Message |
+---------+------+------------------------------------------+
| Warning | 1642 | Writing to a server with high disk usage |
+---------+------+------------------------------------------+
1 row in set (0.00 sec)
With BLOCK:
mysql> INSERT INTO t1() VALUES();
ERROR 3164 (HY000): Aborted by Audit API ('MYSQL_AUDIT_TABLE_ACCESS_INSERT';1).
This message is also written to the error log:
2018-02-21T08:55:10.490978Z 12 [ERROR] Plugin maxdiskusage reported: 'BLOCKING QUERY: Free filesystem space on /home (7682 MB) is less than 10000 MB: INSERT INTO t1() VALUES()'
| Setting | Default | Description |
|---|---|---|
maxdiskusage_action |
WARN | WARN, BLOCK or WARN_AND_BLOCK |
maxdiskusage_note |
'' | Note to add to the warning message |
maxdiskusage_minfree |
0 | Act if less than x MB of free space is available |
maxdiskusage_monitor_fs |
/var/lib/mysql | Directory to monitor, usally @@datadir |
maxdiskusage_pct |
100 | Execute the action if over this percentage of usage |
maxdiskusage_block_pct |
100 | Block if over this percentage of usage if action is WARN_AND_BLOCK |
maxdiskusage_warn_skip_count |
1000 | Skip every x events, reduces warning rate |
These can be set with SET GLOBAL, but you probably want to put those in your my.cnf
This is tested against MySQL 5.7 and MySQL 8.0. Pull requests for other MySQL and MariaDB versions are welcome.
Copy the mysql_maxdiskusage directory to the plugin directory of the MySQL source code.
Build the code as usual or just run make maxdiskusag.
Either use the resulting build or copy maxdiskusage.so to the plugin_dir.
https://dev.mysql.com/doc/refman/5.7/en/compiling-plugin-libraries.html
Might contain some code from https://github.com/gkodinov/audit_tripwire
Please open issues and send pull requests on GitHub.
Please format your code with clang-format.