同大多数关系型数据库一样，日志文件是MySQL数据库的重要组成部分。MySQL有几种不同的日志文件，通常包括错误日志文件，二进制日志，通用日志，慢查询日志，等等。这些日志可以帮助我们定位mysqld内部发生的事件，数据库性能故障，记录数据的变更历史，用户恢复数据库等等。二进制日志，也叫binary log，是MySQL Server中最为重要的日志之一，本文主要描述二进制日志。
1、MySQL日志文件系统的组成
2、二进制日志(Binary log)
3、二进制日志相关演示
a、启用二进制日志
--当前环境
root@localhost[(none)]> show variables like '%version%';
+-------------------------+------------------------------+
| Variable_name | Value |
+-------------------------+------------------------------+
| innodb_version | 5.5.39 |
| protocol_version | 10 |
| slave_type_conversions | |
| version | 5.5.39 |
| version_comment | MySQL Community Server (GPL) |
| version_compile_machine | x86_64 |
| version_compile_os | Linux |
+-------------------------+------------------------------+
root@localhost[(none)]> show variables like '%log_bin%';
+---------------------------------+-------+
| Variable_name | Value |
+---------------------------------+-------+
| log_bin | OFF | --该参数用于设定是否启用二进制日志
| log_bin_trust_function_creators | OFF |
| sql_log_bin | ON |
+---------------------------------+-------+
--以下为binary log相关参数
root@localhost[(none)]> show variables like '%binlog%';
+-----------------------------------------+----------------------+
| Variable_name | Value |
+-----------------------------------------+----------------------+
| binlog_cache_size | 32768 |
| binlog_direct_non_transactional_updates | OFF |
| binlog_format | STATEMENT |
| binlog_stmt_cache_size | 32768 |
| innodb_locks_unsafe_for_binlog | OFF |
| max_binlog_cache_size | 18446744073709547520 |
| max_binlog_size | 1073741824 |
| max_binlog_stmt_cache_size | 18446744073709547520 |
| sync_binlog | 0 |
+-----------------------------------------+----------------------+
--当前mysql服务器数据文件的缺省位置
root@localhost[(none)]> show variables like '%datadir%';
+---------------+-----------------+
| Variable_name | Value |
+---------------+-----------------+
| datadir | /var/lib/mysql/ |
+---------------+-----------------+
--停止mysql服务器
suse11b:~ # service mysql stop
Shutting down MySQL.... done
--编辑my.cnf来设定binary log日志位置(注，配置二进制日志路径及文件名后，系统变量log_bin被自动置为on)
suse11b:~ # vi /etc/my.cnf
suse11b:~ # grep -v ^# /etc/my.cnf
[mysqld]
log-error=/tmp/suse11b.err
log_bin=/var/lib/mysql/binarylog/binlog
suse11b:~ # mkdir -p /var/lib/mysql/binarylog
suse11b:~ # chown -R mysql:mysql /var/lib/mysql/binarylog
suse11b:~ # /etc/init.d/mysql start
Starting MySQL.. done
suse11b:~ # ls -hltr /var/lib/mysql/binarylog/*
-rw-rw---- 1 mysql mysql 39 Oct 3 13:41 /var/lib/mysql/binarylog/binlog.index #索引文件
-rw-rw---- 1 mysql mysql 107 Oct 3 13:41 /var/lib/mysql/binarylog/binlog.000001 #日志文件
b、切换日志
suse11b:~ # mysql -uroot -pxxx
root@localhost[(none)]> flush logs;
Query OK, 0 rows affected (0.04 sec)
root@localhost[(none)]> system ls -hltr /var/lib/mysql/binarylog/*
-rw-rw---- 1 mysql mysql 78 Oct 3 13:43 /var/lib/mysql/binarylog/binlog.index
-rw-rw---- 1 mysql mysql 107 Oct 3 13:43 /var/lib/mysql/binarylog/binlog.000002 #切换后产生了000002
-rw-rw---- 1 mysql mysql 147 Oct 3 13:43 /var/lib/mysql/binarylog/binlog.000001
root@localhost[(none)]> system mysqladmin flush-logs #使用mysqladmin命令行工具flush-logs方式切换日志
root@localhost[(none)]> system ls -hltr /var/lib/mysql/binarylog/*
-rw-rw---- 1 mysql mysql 147 Oct 3 13:43 /var/lib/mysql/binarylog/binlog.000001
-rw-rw---- 1 mysql mysql 117 Oct 3 13:45 /var/lib/mysql/binarylog/binlog.index
-rw-rw---- 1 mysql mysql 107 Oct 3 13:45 /var/lib/mysql/binarylog/binlog.000003 #切换后产生了000003
-rw-rw---- 1 mysql mysql 147 Oct 3 13:45 /var/lib/mysql/binarylog/binlog.000002
root@localhost[(none)]> system mysqladmin refresh #使用mysqladmin命令行工具refresh方式切换日志
root@localhost[(none)]> system ls -hltr /var/lib/mysql/binarylog/*
-rw-rw---- 1 mysql mysql 147 Oct 3 13:43 /var/lib/mysql/binarylog/binlog.000001
-rw-rw---- 1 mysql mysql 147 Oct 3 13:45 /var/lib/mysql/binarylog/binlog.000002
-rw-rw---- 1 mysql mysql 156 Oct 3 13:46 /var/lib/mysql/binarylog/binlog.index
-rw-rw---- 1 mysql mysql 107 Oct 3 13:46 /var/lib/mysql/binarylog/binlog.000004 #切换后产生了000004
-rw-rw---- 1 mysql mysql 147 Oct 3 13:46 /var/lib/mysql/binarylog/binlog.000003
c、模拟产生二进制日志及查看内容
root@localhost[(none)]> create database tempdb;
Query OK, 1 row affected (0.00 sec)
root@localhost[(none)]> use tempdb
Database changed
root@localhost[tempdb]> create table tb1(id smallint,val varchar(10));
Query OK, 0 rows affected (0.00 sec)
root@localhost[tempdb]> insert into tb1 values(1,'jack');
Query OK, 1 row affected (0.01 sec)
root@localhost[tempdb]> system strings /var/lib/mysql/binarylog/binlog.000004
bin?8.T
5.5.39-log
z=.T
tempdb
create database tempdb
tempdb
create table tb1(id smallint,val varchar(10))
tempdb
BEGIN
tempdb
insert into tb1 values(1,'jack')
root@localhost[tempdb]> system more /var/lib/mysql/binarylog/binlog.index
/var/lib/mysql/binarylog/binlog.000001
/var/lib/mysql/binarylog/binlog.000002
/var/lib/mysql/binarylog/binlog.000003
/var/lib/mysql/binarylog/binlog.000004
--使用命令行工具mysqlbinlog直接提取二进制日志的内容
root@localhost[tempdb]> system mysqlbinlog /var/lib/mysql/binarylog/binlog.000004
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
/*!40019 SET @@session.max_insert_delayed_threads=0*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
DELIMITER /*!*/;
# at 4
#141003 13:46:39 server id 1 end_log_pos 107 Start: binlog v 4, server v 5.5.39-log created 141003 13:46:39
# Warning: this binlog is either in use or was not closed properly.
BINLOG '
PzguVA8BAAAAZwAAAGsAAAABAAQANS41LjM5LWxvZwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAEzgNAAgAEgAEBAQEEgAAVAAEGggAAAAICAgCAA==
'/*!*/;
# at 107
#141003 14:08:58 server id 1 end_log_pos 194 Query thread_id=1 exec_time=0 error_code=0
SET TIMESTAMP=1412316538/*!*/;
SET @@session.pseudo_thread_id=1/*!*/;
SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/;
SET @@session.sql_mode=0/*!*/;
SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/;
/*!\C utf8 *//*!*/;
SET @@session.character_set_client=33,@@session.collation_connection=33,@@session.collation_server=8/*!*/;
SET @@session.lc_time_names=0/*!*/;
SET @@session.collation_database=DEFAULT/*!*/;
create database tempdb
/*!*/;
# at 194
#141003 14:09:36 server id 1 end_log_pos 304 Query thread_id=1 exec_time=0 error_code=0
use `tempdb`/*!*/;
SET TIMESTAMP=1412316576/*!*/;
create table tb1(id smallint,val varchar(10))
/*!*/;
# at 304
#141003 14:09:56 server id 1 end_log_pos 374 Query thread_id=1 exec_time=0 error_code=0
SET TIMESTAMP=1412316596/*!*/;
BEGIN
/*!*/;
# at 374
#141003 14:09:56 server id 1 end_log_pos 471 Query thread_id=1 exec_time=0 error_code=0
SET TIMESTAMP=1412316596/*!*/;
insert into tb1 values(1,'jack')
/*!*/;
# at 471
#141003 14:09:56 server id 1 end_log_pos 498 Xid = 25
COMMIT/*!*/;
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;
--从以上的内容可以看出二进制日志记录了所有操作的DML语句及其开销，以及一些系统环境变量的信息。
d、管理二进制日志
--对于二进制日志，应尽可能保存在安全的位置，与数据分开存储
--使用show binary logs获取二进制日志相关信息
root@localhost[(none)]> help show binary logs;
Name: 'SHOW BINARY LOGS'
Description:
Syntax:
SHOW BINARY LOGS
SHOW MASTER LOGS
Lists the binary log files on the server. This statement is used as
part of the procedure described in [HELP PURGE BINARY LOGS], that shows
how to determine which logs can be purged.
root@localhost[tempdb]> show binary logs;
+---------------+-----------+
| Log_name | File_size |
+---------------+-----------+
| binlog.000001 | 147 |
| binlog.000002 | 147 |
| binlog.000003 | 147 |
| binlog.000004 | 498 |
+---------------+-----------+
show binlog events用于在二进制日志中显示事件。如果未指定'log_name'，则显示第一个二进制日志。
root@localhost[(none)]> help show binlog events; --获取帮助信息
Name: 'SHOW BINLOG EVENTS'
Description:
Syntax:
SHOW BINLOG EVENTS
[IN 'log_name'] [FROM pos] [LIMIT [offset,] row_count]
Shows the events in the binary log. If you do not specify 'log_name',
the first binary log is displayed.
root@localhost[(none)]> show binlog events;
+---------------+-----+-------------+-----------+-------------+---------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+---------------+-----+-------------+-----------+-------------+---------------------------------------+
| binlog.000001 | 4 | Format_desc | 1 | 107 | Server ver: 5.5.39-log, Binlog ver: 4 |
| binlog.000001 | 107 | Rotate | 1 | 147 | binlog.000002;pos=4 |
+---------------+-----+-------------+-----------+-------------+---------------------------------------+
root@localhost[(none)]> show binlog events in 'binlog.000005'; --binlog.000005不存在，所以报错
ERROR 1220 (HY000): Error when executing command SHOW BINLOG EVENTS: Could not find target log
--下面的这个查询中，前面执行的DML在这里均可以看到
root@localhost[tempdb]> show binlog events in 'binlog.000004';
+---------------+-----+-------------+-----------+-------------+-------------------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+---------------+-----+-------------+-----------+-------------+-------------------------------------------------------------+
| binlog.000004 | 4 | Format_desc | 1 | 107 | Server ver: 5.5.39-log, Binlog ver: 4 |
| binlog.000004 | 107 | Query | 1 | 194 | create database tempdb |
| binlog.000004 | 194 | Query | 1 | 304 | use `tempdb`; create table tb1(id smallint,val varchar(10)) |
| binlog.000004 | 304 | Query | 1 | 374 | BEGIN |
| binlog.000004 | 374 | Query | 1 | 471 | use `tempdb`; insert into tb1 values(1,'jack') |
| binlog.000004 | 471 | Xid | 1 | 498 | COMMIT /* xid=25 */ |
+---------------+-----+-------------+-----------+-------------+-------------------------------------------------------------+
root@localhost[tempdb]> show binlog events in 'binlog.000004' from 374;
+---------------+-----+------------+-----------+-------------+------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+---------------+-----+------------+-----------+-------------+------------------------------------------------+
| binlog.000004 | 374 | Query | 1 | 471 | use `tempdb`; insert into tb1 values(1,'jack') |
| binlog.000004 | 471 | Xid | 1 | 498 | COMMIT /* xid=25 */ |
+---------------+-----+------------+-----------+-------------+------------------------------------------------+
root@localhost[tempdb]> show binlog events in 'binlog.000004' from 374 limit 1;
+---------------+-----+------------+-----------+-------------+------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+---------------+-----+------------+-----------+-------------+------------------------------------------------+
| binlog.000004 | 374 | Query | 1 | 471 | use `tempdb`; insert into tb1 values(1,'jack') |
+---------------+-----+------------+-----------+-------------+------------------------------------------------+
d、删除历史日志
--使用purge手动删除指定日志
--使用expire-log-days删除失效日志，设置变量expire_logs_days，删除超出这个变量保留期之前的所有日志被删除
--自动日志删除通常发生在服务器启动以及日志flush
--reset master方式
root@localhost[(none)]> help purge;
Name: 'PURGE BINARY LOGS'
Description:
Syntax:
PURGE { BINARY | MASTER } LOGS
{ TO 'log_name' | BEFORE datetime_expr }
Examples:
PURGE BINARY LOGS TO 'mysql-bin.010';
PURGE BINARY LOGS BEFORE '2008-04-02 22:46:26';
root@localhost[tempdb]> purge binary logs to 'binlog.000003';
Query OK, 0 rows affected (0.12 sec)
root@localhost[tempdb]> show binary logs;
+---------------+-----------+
| Log_name | File_size |
+---------------+-----------+
| binlog.000003 | 147 |
| binlog.000004 | 498 |
+---------------+-----------+
root@localhost[tempdb]> system ls -hltr /var/lib/mysql/binarylog/*
-rw-rw---- 1 mysql mysql 147 Oct 3 13:46 /var/lib/mysql/binarylog/binlog.000003
-rw-rw---- 1 mysql mysql 498 Oct 3 14:09 /var/lib/mysql/binarylog/binlog.000004
-rw-rw---- 1 mysql mysql 78 Oct 3 14:23 /var/lib/mysql/binarylog/binlog.index
--使用before子句purge日志，binlog.000003被删除
root@localhost[tempdb]> purge binary logs before '2014-10-03 14:09:56';
Query OK, 0 rows affected (0.02 sec)
root@localhost[tempdb]> show binary logs;
+---------------+-----------+
| Log_name | File_size |
+---------------+-----------+
| binlog.000004 | 498 |
+---------------+-----------+
--Author: Leshami
--Blog : http://blog.csdn.net/leshami
--重置所有日志
--reset master将删除在索引文件中列出所有的日志文件并重置索引文件，最后生成一个新的binlog文件。
--该操作之前先备份binlog至其它位置以备以后需要。
root@localhost[tempdb]> help reset master;
Name: 'RESET MASTER'
Description:
Syntax:
RESET MASTER
Deletes all binary log files listed in the index file, resets the
binary log index file to be empty, and creates a new binary log file.
This statement is intended to be used only when the master is started
for the first time.
root@localhost[tempdb]> reset master;
Query OK, 0 rows affected (0.13 sec)
root@localhost[tempdb]> show binary logs;
+---------------+-----------+
| Log_name | File_size |
+---------------+-----------+
| binlog.000001 | 107 | --reset之后，从000001开始生成全新空日志
+---------------+-----------+
--expire_log系统变量控制二进制日志自动删除的天数。默认值为0,表示“没有自动删除”。启动时和二进制日志循环时可能删除。
root@localhost[tempdb]> show variables like 'expire_log%';
+------------------+-------+
| Variable_name | Value |
+------------------+-------+
| expire_logs_days | 0 |
+------------------+-------+
root@localhost[tempdb]> set expire_logs_days=7; --提示次系统变量为全局变量
ERROR 1229 (HY000): Variable 'expire_logs_days' is a GLOBAL variable and should be set with SET GLOBAL
root@localhost[tempdb]> set global expire_logs_days=7; --设置
Query OK, 0 rows affected (0.01 sec)
root@localhost[tempdb]> select @@expire_logs_days;
+--------------------+
| @@expire_logs_days |
+--------------------+
| 7 |
+--------------------+
![[Web front-end] Permulaan pantas Node.js](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
