目录
如果不知道错误日志的位置可以登录mysql服务查找错误日志变量
localhost-bin.index 文件：记录了累计共有多少个二进制文件
查看当前使用的是哪个二进制文件 show master status
一个二进制文件是否记录了整个mysqld进程里所有的库的操作？
知识点1：为什么需要日志信息？
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知识点2：错误日志 error
示例：查看mysql里面的日志变量信息。
root@(none) 10:28 mysql>show variables like "%log%";
+--------------------------------------------+---------------------------------------+
| Variable_name | Value |
+--------------------------------------------+---------------------------------------+
| back_log | 80 |
| binlog_cache_size | 32768 |
| binlog_checksum | CRC32 |
| binlog_direct_non_transactional_updates | OFF |
| binlog_error_action | ABORT_SERVER |
| binlog_format | ROW |
| binlog_group_commit_sync_delay | 0 |
| binlog_group_commit_sync_no_delay_count | 0 |
| binlog_gtid_simple_recovery | ON |
| binlog_max_flush_queue_time | 0 |
| binlog_order_commits | ON |
| binlog_row_image | FULL |
| binlog_rows_query_log_events | OFF |
| binlog_stmt_cache_size | 32768 |
| binlog_transaction_dependency_history_size | 25000 |
| binlog_transaction_dependency_tracking | COMMIT_ORDER |
| expire_logs_days | 0 |
| general_log | OFF |
| general_log_file | /data/mysql/localhost.log |
| innodb_api_enable_binlog | OFF |
| innodb_flush_log_at_timeout | 1 |
| innodb_flush_log_at_trx_commit | 1 |
| innodb_locks_unsafe_for_binlog | OFF |
| innodb_log_buffer_size | 16777216 |
| innodb_log_checksums | ON |
| innodb_log_compressed_pages | ON |
| innodb_log_file_size | 50331648 |
| innodb_log_files_in_group | 2 |
| innodb_log_group_home_dir | ./ |
| innodb_log_write_ahead_size | 8192 |
| innodb_max_undo_log_size | 1073741824 |
| innodb_online_alter_log_max_size | 134217728 |
| innodb_undo_log_truncate | OFF |
| innodb_undo_logs | 128 |
| log_bin | OFF |
| log_bin_basename | |
| log_bin_index | |
| log_bin_trust_function_creators | OFF |
| log_bin_use_v1_row_events | OFF |
| log_builtin_as_identified_by_password | OFF |
| log_error | ./localhost.localdomain.err |
| log_error_verbosity | 3 |
| log_output | FILE |
| log_queries_not_using_indexes | OFF |
| log_slave_updates | OFF |
| log_slow_admin_statements | OFF |
| log_slow_slave_statements | OFF |
| log_statements_unsafe_for_binlog | ON |
| log_syslog | OFF |
| log_syslog_facility | daemon |
| log_syslog_include_pid | ON |
| log_syslog_tag | |
| log_throttle_queries_not_using_indexes | 0 |
| log_timestamps | UTC |
| log_warnings | 2 |
| max_binlog_cache_size | 18446744073709547520 |
| max_binlog_size | 1073741824 |
| max_binlog_stmt_cache_size | 18446744073709547520 |
| max_relay_log_size | 0 |
| relay_log | |
| relay_log_basename | /data/mysql/localhost-relay-bin |
| relay_log_index | /data/mysql/localhost-relay-bin.index |
| relay_log_info_file | relay-log.info |
| relay_log_info_repository | FILE |
| relay_log_purge | ON |
| relay_log_recovery | OFF |
| relay_log_space_limit | 0 |
| slow_query_log | OFF |
| slow_query_log_file | /data/mysql/localhost-slow.log |
| sql_log_bin | ON |
| sql_log_off | OFF |
| sync_binlog | 1 |
| sync_relay_log | 10000 |
| sync_relay_log_info | 10000 |
+--------------------------------------------+---------------------------------------+
74 rows in set (0.00 sec)
错误日志的位置：
[root@localhost mysql]# ls
auto.cnf ibdata1 mysql sanchuang ucar_cloud
ca-key.pem ib_logfile0 mysql.sock server-cert.pem wangsh
ca.pem ib_logfile1 mysql.sock.lock server-key.pem
client-cert.pem ibtmp1 performance_schema student
client-key.pem localhost.localdomain.err private_key.pem sys
ib_buffer_pool localhost.localdomain.pid public_key.pem test
[root@localhost mysql]#
如果不知道错误日志的位置可以登录mysql服务查找错误日志变量
root@(none) 10:34 mysql>show variables like "log_error";
+---------------+-----------------------------+
| Variable_name | Value |
+---------------+-----------------------------+
| log_error | ./localhost.localdomain.err |
+---------------+-----------------------------+
1 row in set (0.01 sec)
错误日志记录了什么内容？
示例：mysql登录失败会记录错误日志。
使用tail -f 监控日志文件
[root@localhost mysql]# tail -f localhost.localdomain.err
错误输入密码：
生成错误日志：
日志文件配置错误：
生成警告
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知识点3：慢日志 slow_query_log
慢日志有什么作用？
慢日志默认是关闭的
root@(none) 10:57 mysql>show variables like "%slow_query%";
+---------------------+--------------------------------+
| Variable_name | Value |
+---------------------+--------------------------------+
| slow_query_log | OFF |
| slow_query_log_file | /data/mysql/localhost-slow.log |
+---------------------+--------------------------------+
2 rows in set (0.00 sec)
sql语句执行时间多长算慢日志？
root@(none) 10:45 mysql>show variables like "%long_query%";
+-----------------+-----------+
| Variable_name | Value |
+-----------------+-----------+
| long_query_time | 10.000000 |
+-----------------+-----------+
1 row in set (0.00 sec)
在配置文件里面开启慢日志
# slow log
slow_query_log = 1
long_query_time = 0.001 # 标准
# 在写入慢日志中包含慢管理语句。
log_slow_admin_statements = 1
root@(none) 11:34 mysql>show variables like "%slow%";
+---------------------------+--------------------------------+
| Variable_name | Value |
+---------------------------+--------------------------------+
| log_slow_admin_statements | ON |
| log_slow_slave_statements | OFF |
| slow_launch_time | 2 |
| slow_query_log | ON |
| slow_query_log_file | /data/mysql/localhost-slow.log |
+---------------------------+--------------------------------+
5 rows in set (0.01 sec)
root@(none) 11:35 mysql>
root@(none) 11:52 mysql>show variables like "%slow%";
+---------------------------+--------------------------------+
| Variable_name | Value |
+---------------------------+--------------------------------+
| log_slow_admin_statements | ON |
| log_slow_slave_statements | OFF |
| slow_launch_time | 2 |
| slow_query_log | ON |
| slow_query_log_file | /data/mysql/localhost-slow.log |
+---------------------------+--------------------------------+
5 rows in set (0.01 sec)
root@(none) 11:52 mysql>
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知识点4:通用日志 general log
root@(none) 12:13 mysql>show variables like "%general%";
+------------------+---------------------------+
| Variable_name | Value |
+------------------+---------------------------+
| general_log | OFF |
| general_log_file | /data/mysql/localhost.log |
+------------------+---------------------------+
2 rows in set (0.00 sec)
# general 日志
general_log
root@(none) 12:15 mysql>show variables like "%general%"
-> ;
+------------------+---------------------------+
| Variable_name | Value |
+------------------+---------------------------+
| general_log | ON |
| general_log_file | /data/mysql/localhost.log |
+------------------+---------------------------+
2 rows in set (0.00 sec)
root@(none) 12:15 mysql>
可以看到，开启general通用日志以后，所有使用过的sql语句都会记录在 localhost.log文件里面
root@(none) 14:40 mysql>use wangsh;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
root@wangsh 14:40 mysql>show tables;
+------------------+
| Tables_in_wangsh |
+------------------+
| shirts |
| tran_demo |
+------------------+
2 rows in set (0.00 sec)
root@wangsh 14:40 mysql>desc tran_demo;
+-------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id | int(11) | YES | | NULL | |
| name | varchar(20) | YES | | NULL | |
+-------+-------------+------+-----+---------+-------+
2 rows in set (0.00 sec)
root@wangsh 14:40 mysql>
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知识点5：二进制日志 binary log
二进制日志的作用？
root@wangsh 14:51 mysql>show variables like "%log_bin%";
+---------------------------------+-------+
| Variable_name | Value |
+---------------------------------+-------+
| log_bin | OFF |
| log_bin_basename | |
| log_bin_index | |
| log_bin_trust_function_creators | OFF |
| log_bin_use_v1_row_events | OFF |
| sql_log_bin | ON |
+---------------------------------+-------+
6 rows in set (0.00 sec)
示例：在配置文件里面开启二进制日志
# binary log
log_bin
server_id = 1
root@(none) 14:54 mysql>show variables like "%log_bin%";
+---------------------------------+---------------------------------+
| Variable_name | Value |
+---------------------------------+---------------------------------+
| log_bin | ON |
| log_bin_basename | /data/mysql/localhost-bin |
| log_bin_index | /data/mysql/localhost-bin.index |
| log_bin_trust_function_creators | OFF |
| log_bin_use_v1_row_events | OFF |
| sql_log_bin | ON |
+---------------------------------+---------------------------------+
6 rows in set (0.00 sec)
root@(none) 14:56 mysql>
[root@localhost mysql]# ls
auto.cnf ib_logfile1 mysql server-key.pem
ca-key.pem ibtmp1 mysql.sock student
ca.pem localhost-bin.000001 mysql.sock.lock sys
client-cert.pem localhost-bin.index performance_schema test
client-key.pem localhost.localdomain.err private_key.pem ucar_cloud
ib_buffer_pool localhost.localdomain.pid public_key.pem wangsh
ibdata1 localhost.log sanchuang
ib_logfile0 localhost-slow.log server-cert.pem
[root@localhost mysql]#
localhost-bin.index 文件：记录了累计共有多少个二进制文件
[root@localhost mysql]# ls
auto.cnf ib_logfile1 mysql server-key.pem
ca-key.pem ibtmp1 mysql.sock student
ca.pem localhost-bin.000001 mysql.sock.lock sys
client-cert.pem localhost-bin.index performance_schema test
client-key.pem localhost.localdomain.err private_key.pem ucar_cloud
ib_buffer_pool localhost.localdomain.pid public_key.pem wangsh
ibdata1 localhost.log sanchuang
ib_logfile0 localhost-slow.log server-cert.pem
[root@localhost mysql]# cat localhost-bin.index
./localhost-bin.000001
[root@localhost mysql]# service mysqld restart
Shutting down MySQL.... SUCCESS!
Starting MySQL. SUCCESS!
[root@localhost mysql]# ls
auto.cnf ib_logfile1 localhost-slow.log server-cert.pem
ca-key.pem ibtmp1 mysql server-key.pem
ca.pem localhost-bin.000001 mysql.sock student
client-cert.pem localhost-bin.000002 mysql.sock.lock sys
client-key.pem localhost-bin.index performance_schema test
ib_buffer_pool localhost.localdomain.err private_key.pem ucar_cloud
ibdata1 localhost.localdomain.pid public_key.pem wangsh
ib_logfile0 localhost.log sanchuang
[root@localhost mysql]# cat localhost-bin.index
./localhost-bin.000001
./localhost-bin.000002
查看当前使用的是哪个二进制文件 show master status
root@(none) 15:00 mysql>show master status;
+----------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+----------------------+----------+--------------+------------------+-------------------+
| localhost-bin.000002 | 154 | | | |
+----------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
root@(none) 15:00 mysql>
查看所有二进制文件和大小 show binary logs
root@(none) 15:03 mysql>show binary logs;
+----------------------+-----------+
| Log_name | File_size |
+----------------------+-----------+
| localhost-bin.000001 | 177 |
| localhost-bin.000002 | 205 |
| localhost-bin.000003 | 154 |
+----------------------+-----------+
3 rows in set (0.00 sec)
root@(none) 15:07 mysql>
一个二进制文件是否记录了整个mysqld进程里所有的库的操作？
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知识点6：哪些行为会产生新的二进制文件？
1、service mysqld restart
2、flush logs；
root@(none) 15:00 mysql>flush logs;
Query OK, 0 rows affected (0.00 sec)
root@(none) 15:03 mysql>show master status;
+----------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+----------------------+----------+--------------+------------------+-------------------+
| localhost-bin.000003 | 154 | | | |
+----------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
root@(none) 15:03 mysql>
[root@localhost mysql]# ls
auto.cnf ib_logfile1 localhost.log sanchuang
ca-key.pem ibtmp1 localhost-slow.log server-cert.pem
ca.pem localhost-bin.000001 mysql server-key.pem
client-cert.pem localhost-bin.000002 mysql.sock student
client-key.pem localhost-bin.000003 mysql.sock.lock sys
ib_buffer_pool localhost-bin.index performance_schema test
ibdata1 localhost.localdomain.err private_key.pem ucar_cloud
ib_logfile0 localhost.localdomain.pid public_key.pem wangsh
[root@localhost mysql]#
3、当日志达到最大值1G的时候，也会产生新的日志
root@(none) 15:07 mysql>show variables like "max_binlog_size";
+-----------------+------------+
| Variable_name | Value |
+-----------------+------------+
| max_binlog_size | 1073741824 |
+-----------------+------------+
1 row in set (0.00 sec)
root@(none) 15:15 mysql>
root@(none) 15:15 mysql>select 1073741824/1024/1024;
+----------------------+
| 1073741824/1024/1024 |
+----------------------+
| 1024.00000000 |
+----------------------+
1 row in set (0.00 sec)
root@(none) 15:17 mysql>
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知识点7：查看二进制文件 mysqlbinlog
root@ucar_cloud 15:33 mysql>use student;
Database changed
root@student 15:34 mysql>shwo tables;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'shwo tables' at line 1
root@student 15:34 mysql>show tables;
Empty set (0.00 sec)
root@student 15:34 mysql>create table test(id int, name varchar(20));
Query OK, 0 rows affected (0.01 sec)
root@student 15:35 mysql>insert into test(id,name) values(1,'wang');
Query OK, 1 row affected (0.00 sec)
[root@localhost mysql]# mysqlbinlog -v localhost-bin.000003
# at 535
#220812 15:35:34 server id 1 end_log_pos 580 CRC32 0xdd2e8bd1 Write_rows: table id 113 flags: STMT_END_F
BINLOG '
xgL2YhMBAAAANQAAABcCAAAAAHEAAAAAAAEAB3N0dWRlbnQABHRlc3QAAgMPAjwAA5EKdrY=
xgL2Yh4BAAAALQAAAEQCAAAAAHEAAAAAAAEAAgAC//wBAAAABHdhbmfRiy7d
'/*!*/;
### INSERT INTO `student`.`test`
### SET
### @1=1
### @2='wang'
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知识点8：Innodb存储引擎架构
redo log
redo log可以简单分为以下两个部分：
redo的整体流程
undo log
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知识点9：事务的执行过程
过程：
参考资料：
https://www.jianshu.com/p/20e10ed721d0
mysql之事务执行过程和ACID分析；一文读懂undolog、redolog、binlog刷盘时机和意义 - 知乎
