How to enable, disable, and view mysql logs

In mysql, logs are classified into error logs:-log-err query log:-log slow query log:-log-slow-queries update log:-log-update BINARY log: -Below I will introduce the methods for enabling, disabling, and viewing mysql logs.

1. Error Log
Use the-log-error [= file_name] Option to specify the location where mysqld saves the error log file. If the file_name value is not specified, mysqld uses the error log name host_name.err and writes the log file to the data directory. If you execute flush logs, the error log uses-old to rename the suffix and mysqld to create a new empty log file. (If the-log-error option is not provided, it will not be renamed ).

If-log-error is not specified, or (in Windows) if you use the-console option, the error is written to stderr. Standard output is usually your terminal.

2. General query logs
Use the-log [= file_name] Or-l [file_name] Option to start it. If the file_name value is not specified, the default name is host_name.log.

3. View logs

Check whether logs are enabled

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Mysql> show variables like 'Log _ % ';

View the current log activation status

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Mysql> show master status;

Display binary logs? ? /P>

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Mysql> show master logs;

4. Use mysqlbinlog to view binary log files

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Shell> mysqlbinlog/var/log/mysql/mysql-bin.000001 Or shell> mysqlbinlog/var/log/mysql/mysql-bin.000001 | tail Or shell> mysqlbinlog/var/log/mysql/mysql-bin.000001-no-default

If an error occurs, the following error occurs:

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/Usr/local/mysql/bin/mysqlbinlog: unknown variable 'default-character-set = utf8 ′

This problem is caused by the addition

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Default-character-set = utf8

.

Mysqlbinlog does not support this setting. There are two solutions:

1. modify the configuration file my. cnf (my. ini in windows)
Comment out default-character-set = utf8
2. Add the parameter-no-default during execution.

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Shell & gt; mysqlbinlog-no-default/var/log/mysql/mysql-bin.000001 | tail

You can export the log content to the. SQL file for ease of viewing.

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Mysqlbinlog ../log-bin/logbin.000001-> a. SQL C:/Program Files/MySQL Server 5.0/bin> C:/Program Files/MySQL Server 5.0/bin> mysqlbinlog ../log_bin_ljs/logbin.000001 /*! 40019 SET @ session. max_insert_delayed_threads = 0 */; /*! 50003 SET @ OLD_COMPLETION_TYPE = @ COMPLETION_TYPE, COMPLETION_TYPE = 0 */; DELIMITER /*! */; # At 4 #100830 16:30:55 server id 1 end_log_pos 98 Start: binlog v 4, server v 5.0. 67-community-nt-log created 100830 16:30:55 at startup # Warning: this binlog was not closed properly. Most probably mysqld crashed wri Ting it. ROLLBACK /*! */; DELIMITER; # End of log file ROLLBACK/* added by mysqlbinlog */; /*! 50003 SET COMPLETION_TYPE = @ OLD_COMPLETION_TYPE */; C:/Program Files/MySQL Server 5.0/bin>