SQL Error Log Plugin
Contents
The SQL_ERROR_LOG
plugin collects errors sent to clients in a log file defined by sql_error_log_filename, so that they can later be analyzed. The log file can be rotated if sql_error_log_rotate is set.
Errors are logged as they happen and an error will be logged even if it was handled by a condition handler and was never technically sent to the client.
Comments are also logged, which can make the log easier to search. But this is only possible if the client does not strip the comments away. For example, the mariadb command-line client only leaves comments when started with the --comments option.
Installing the Plugin
Although the plugin's shared library is distributed with MariaDB by default, the plugin is not actually installed by MariaDB by default. There are two methods that can be used to install the plugin with MariaDB.
The first method can be used to install the plugin without restarting the server. You can install the plugin dynamically by executing INSTALL SONAME or INSTALL PLUGIN. For example:
INSTALL SONAME 'sql_errlog';
The second method can be used to tell the server to load the plugin when it starts up. The plugin can be installed this way by providing the --plugin-load or the --plugin-load-add options. This can be specified as a command-line argument to mariadbd or it can be specified in a relevant server option group in an option file. For example:
[mariadb] ... plugin_load_add = sql_errlog
Uninstalling the Plugin
You can uninstall the plugin dynamically by executing UNINSTALL SONAME or UNINSTALL PLUGIN. For example:
UNINSTALL SONAME 'sql_errlog';
If you installed the plugin by providing the --plugin-load or the --plugin-load-add options in a relevant server option group in an option file, then those options should be removed to prevent the plugin from being loaded the next time the server is restarted.
Logging
The log format until MariaDB 10.10 is:
Time User Error_code: Error_message : Query
Starting from MariaDB 10.11, the format is:
Time User Type Error_code: Error_message : Query
Each separated by a space or : as above
Option | Description | Version |
---|---|---|
Time | Time (YYYY-MM-DD hh-mm-ss) | 5.5.22 |
Thread Id | Thread Id of current thread | 10.6.17 |
User | privilege_user [login_user_name] @ hostname [ip] | 5.5.22 |
Database name | Name of the currently selected database | 10.6.17 |
Type | ERROR or WARNING | 10.11.6 |
Error_code | OS error, MariaDB storage engine code (120-199) or MariaDB internal error code (1000-) | 5.5.22 |
Query | Query text | 5.5.22 |
Example of Logs
2023-10-31 15:54:37 root[root] @ localhost [] ERROR 1146: Table 'test.t_doesnt_exist' doesn't exist : select * from t_doesnt_exist 2023-10-31 15:54:37 root[root] @ localhost [] ERROR 1064: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'syntax_error_query' at line 1 : syntax_error_query 2023-10-31 15:54:37 root[root] @ localhost [] ERROR 1146: Table 'test.temptab' doesn't exist : SELECT `c` FROM `temptab` 2023-11-01 11:31:15 [monty] @ storm [192.168.0.12] ERROR 1051: Unknown table 'test.t1' : drop table t1
Starting from 10.6.17, when the sql_error_log_with_db_and_thread_info
variable is enabled, the log also contains thread id and database name.
Example, when select is done from a non existing table with enabled sql_error_log_with_db_and_thread_info
, on database test
and thread id 4, the log will have:
2023-10-31 15:54:37 4 root[root] @ localhost [] `test` ERROR 1146: Table 'test.t_doesnt_exist' doesn't exist : select * from t_doesnt_exist
Example Usage
install plugin SQL_ERROR_LOG soname 'sql_errlog'; Query OK, 0 rows affected (0.00 sec) use test; Database changed set sql_mode='STRICT_ALL_TABLES,NO_ENGINE_SUBSTITUTION'; Query OK, 0 rows affected (0.00 sec) CREATE TABLE foo2 (id int) ENGINE=WHOOPSIE; ERROR 1286 (42000): Unknown storage engine 'WHOOPSIE' \! cat data/sql_errors.log 2013-03-19 9:38:40 msandbox[msandbox] @ localhost [] ERROR 1286: Unknown storage engine 'WHOOPSIE' : CREATE TABLE foo2 (id int) ENGINE=WHOOPSIE
Versions
Version | Status | Introduced |
---|---|---|
1.1 | Stable | MariaDB 10.6.17 |
1.0 | Stable | MariaDB 10.1.13 |
1.0 | Gamma | MariaDB 10.0.10 |
1.0 | Alpha | MariaDB 5.5.22 |