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db/MySQL系列/06-MySQL系列之-日志管理

2019-12-24

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1.错误日志(log_error)

1.1 作用

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记录启动\关闭\日常运行过程中,状态信息,警告,错误

1.2 错误日志配置

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默认就是开启的:  /数据路径下/hostname.err
手工设定:
Master [(none)]>select @@log_error;
vim /etc/my.cnf
log_error=/var/log/mysql.log
log_timestamps=system
重启生效
show variables like 'log_error';

1.3 日志内容查看

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主要关注[ERROR],看上下文

2. binlog(binary logs):二进制日志 *****

2.1 作用

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(1)备份恢复必须依赖二进制日志
(2)主从环境必须依赖二进制日志

2.2 binlog配置 (5.7必须加server_id)

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注意:MySQL默认是没有开启二进制日志的。
基础参数查看:
开关:
[(none)]>select @@log_bin;
日志路径及名字
[(none)]>select @@log_bin_basename;
服务ID号:
[(none)]>select @@server_id;
二进制日志格式:
[(none)]>select @@binlog_format;
双一标准之二:
[(none)]>select @@sync_binlog;

2.2.1 创建日志目录

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mkdir /data/binlog
chown -R mysql.mysql /data/binlog

2.2.2 修改配置文件

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vim /etc/my.cnf
server_id=6 ----->5.6中,单机可以不需要此参数
log_bin=/data/binlog/mysql-bin
binlog_format=row

2.2.3 重启数据库生效

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[root@db01 mysql]# /etc/init.d/mysqld restart

2.2.4 参数说明

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server_id=3306 
主要是在主从复制过程中必须要加的,但是在5.7版本中,要用以下参数(log_bin),开启binlog日志,即使是单机也是必加的
log_bin=/data/binlog/mysql-bin
(1)开启二进制日志功能
(2)设置二进制日志目录及名称前缀
binlog_format=row
binlog的记录格式??

2.3 binlog记录了什么?

2.3.0 引入

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binlog是SQL层的功能。记录的是变更SQL语句,不记录查询语句。

2.3.1 记录SQL语句种类

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DDL :原封不动的记录当前DDL(statement语句方式)。
DCL :原封不动的记录当前DCL(statement语句方式)。
DML :只记录已经提交的事务DML

2.3.2 DML三种记录方式

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binlog_formatbinlog的记录格式)参数影响
(1)statement(5.6默认)SBR(statement based replication) :语句模式原封不动的记录当前DML
(2)ROW(5.7 默认值) RBR(ROW based replication) :记录数据行的变化(用户看不懂,需要工具分析)
(3)mixed(混合)MBR(mixed based replication)模式 :以上两种模式的混合

2.3.3 面试题

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SBR与RBR模式的对比
STATEMENT:可读性较高,日志量少,但是不够严谨
ROW :可读性很低,日志量大,足够严谨
update t1 set xxx=xxx where id>1000 ? -->一共500w行,row模式怎么记录的日志
为什么row模式严谨?
id name intime
insert into t1 values(1,'zs',now())
我们建议使用:row记录模式

2.4 event(事件)是什么?

2.4.1 事件的简介

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二进制日志的最小记录单元
对于DDL,DCL,一个语句就是一个event
对于DML语句来讲:只记录已提交的事务。
例如以下列子,就被分为了4event
begin; 120 - 340
DML1 340 - 460
DML2 460 - 550
commit; 550 - 760

2.4.2 event的组成

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三部分构成:
(1) 事件的开始标识
(2) 事件内容
(3) 事件的结束标识
Position:
开始标识: at 194
结束标识: end_log_pos 254
194? 254?
某个事件在binlog中的相对位置号
位置号的作用是什么?
为了方便我们截取事件

2.5 日志文件查看

2.5.1 查看日志的开启情况

log_bin参数设置的路径,可以找到二进制日志

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Master [(none)]>show variables like '%log_bin%';
+---------------------------------+------------------------------+
| Variable_name | Value |
+---------------------------------+------------------------------+
| log_bin | ON |
| log_bin_basename | /data/binlog/mysql-bin |
| log_bin_index | /data/binlog/mysql-bin.index |
| log_bin_trust_function_creators | OFF |
| log_bin_use_v1_row_events | OFF |
| sql_log_bin | ON |
+---------------------------------+------------------------------+
6 rows in set (0.01 sec)

2.5.2 查看一共多少个binlog

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Master [(none)]>show binary logs;
+------------------+-----------+
| Log_name | File_size |
+------------------+-----------+
| mysql-bin.000001 | 154 |
+------------------+-----------+
1 row in set (0.01 sec)

Master [(none)]>flush logs;
Query OK, 0 rows affected (0.03 sec)

Master [(none)]>flush logs;
Query OK, 0 rows affected (0.01 sec)

Master [(none)]>show binary logs;
+------------------+-----------+
| Log_name | File_size |
+------------------+-----------+
| mysql-bin.000001 | 201 |
| mysql-bin.000002 | 201 |
| mysql-bin.000003 | 154 |
+------------------+-----------+
3 rows in set (0.00 sec)

Master [(none)]>

2.5.3 查看mysql正在使用的日志文件

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Master [(none)]>show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000003 | 154 | | | |
+------------------+----------+--------------+------------------+-------------------+
Master [(none)]>

file:当前MySQL正在使用的文件名
Position:最后一个事件的结束位置号

2.6 日志内容查看

2.6.1 event查看

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Master [binlog]>show binlog events in 'mysql-bin.000003';
+------------------+-----+----------------+-----------+-------------+----------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+-----+----------------+-----------+-------------+----------------------------------------+
| mysql-bin.000003 | 4 | Format_desc | 6 | 123 | Server ver: 5.7.20-log, Binlog ver: 4 |
| mysql-bin.000003 | 123 | Previous_gtids | 6 | 154 | |
| mysql-bin.000003 | 154 | Anonymous_Gtid | 6 | 219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000003 | 219 | Query | 6 | 319 | create database binlog |
| mysql-bin.000003 | 319 | Anonymous_Gtid | 6 | 384 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000003 | 384 | Query | 6 | 486 | use `binlog`; create table t1 (id int) |
+------------------+-----+----------------+-----------+-------------+----------------------------------------+

Log_name:binlog文件名
Pos:开始的position *****
Event_type:事件类型
Format_desc:格式描述,每一个日志文件的第一个事件,多用户没有意义,MySQL识别binlog必要信息
Server_id:mysql服务号标识
End_log_pos:事件的结束位置号 *****
Info:事件内容*****
补充:
SHOW BINLOG EVENTS
[IN 'log_name']
[FROM pos]
[LIMIT [offset,] row_count]
[root@db01 binlog]# mysql -e "show binlog events in 'mysql-bin.000004'" |grep drop

2.6.2 binlog文件内容详细查看

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mysqlbinlog /data/mysql/mysql-bin.000006
mysqlbinlog --base64-output=decode-rows -vvv /data/binlog/mysql-bin.000003
mysqlbinlog -d binlog /data/binlog/mysql-bin.000003
[root@db01 binlog]# mysqlbinlog --start-datetime='2019-05-06 17:00:00' --stop-datetime='2019-05-06 17:01:00' /data/binlog/mysql-bin.000004

2.7 基于Position号进行日志截取

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核心就是找截取的起点和终点
--start-position=321
--stop-position=513
mysqlbinlog --start-position=219 --stop-position=1347 /data/binlog/mysql-bin.000003 >/tmp/bin.sql

案例: 使用binlog日志进行数据恢复
模拟:
1.
[(none)]>create database binlog charset utf8;
2.
[(none)]>use binlog;
[binlog]>create table t1(id int);
3.
[binlog]>insert into t1 values(1);
[binlog]>commit;
[binlog]>insert into t1 values(2);
[binlog]>commit;
[binlog]>insert into t1 values(3);
[binlog]>commit;
4.
[binlog]>drop database binlog;
恢复:
[(none)]>show master status ;
[(none)]>show binlog events in 'mysql-bin.000004';
[root@db01 binlog]# mysqlbinlog --start-position=1227 --stop-position=2342 /data/binlog/mysql-bin.000004 >/tmp/bin.sql
[(none)]>set sql_Log_bin=0;
[(none)]>source /tmp/bin.sql

面试案例:
1. 备份策略每天全备,有全量的二进制日志
2.业务中一共10个库,其中一个被误drop了
3. 需要在其他9个库正常工作过程中进行数据恢复

2.8 binlog日志的GTID新特性

2.8.1 GTID 介绍

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5.6 版本新加的特性,5.7中做了加强
5.6 中不开启,没有这个功能.
5.7 中的GTID,即使不开也会有自动生成
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'

2.8.2. GTID(Global Transaction ID)

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是对于一个已提交事务的编号,并且是一个全局唯一的编号。
它的官方定义如下:

GTID = source_id :transaction_id
7E11FA47-31CA-19E1-9E56-C43AA21293967:29

重要参数介绍:

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vim /etc/my.cnf
gtid-mode=on
enforce-gtid-consistency=true
systemctl restart mysqld

Master [(none)]>create database gtid charset utf8;
Query OK, 1 row affected (0.01 sec)

Master [(none)]>show master status ;
+------------------+----------+--------------+------------------+----------------------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+----------------------------------------+
| mysql-bin.000004 | 326 | | | dff98809-55c3-11e9-a58b-000c2928f5dd:1 |
+------------------+----------+--------------+------------------+----------------------------------------+
1 row in set (0.00 sec)

Master [(none)]>use gtid
Database changed
Master [gtid]>create table t1 (id int);
Query OK, 0 rows affected (0.01 sec)

Master [gtid]>show master status ;
+------------------+----------+--------------+------------------+------------------------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+------------------------------------------+
| mysql-bin.000004 | 489 | | | dff98809-55c3-11e9-a58b-000c2928f5dd:1-2 |
+------------------+----------+--------------+------------------+------------------------------------------+
1 row in set (0.00 sec)

Master [gtid]>create table t2 (id int);
Query OK, 0 rows affected (0.01 sec)

Master [gtid]>create table t3 (id int);
Query OK, 0 rows affected (0.02 sec)

Master [gtid]>show master status ;
+------------------+----------+--------------+------------------+------------------------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+------------------------------------------+
| mysql-bin.000004 | 815 | | | dff98809-55c3-11e9-a58b-000c2928f5dd:1-4 |
+------------------+----------+--------------+------------------+------------------------------------------+
1 row in set (0.00 sec)

Master [gtid]>begin;
Query OK, 0 rows affected (0.00 sec)

Master [gtid]>insert into t1 values(1);
Query OK, 1 row affected (0.00 sec)

Master [gtid]>commit;
Query OK, 0 rows affected (0.00 sec)

Master [gtid]>show master status ;
+------------------+----------+--------------+------------------+------------------------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+------------------------------------------+
| mysql-bin.000004 | 1068 | | | dff98809-55c3-11e9-a58b-000c2928f5dd:1-5 |
+------------------+----------+--------------+------------------+------------------------------------------+
1 row in set (0.00 sec)

Master [gtid]>begin;
Query OK, 0 rows affected (0.00 sec)

Master [gtid]>insert into t2 values(1);
Query OK, 1 row affected (0.00 sec)

Master [gtid]>commit;
Query OK, 0 rows affected (0.01 sec)

Master [gtid]>show master status ;
+------------------+----------+--------------+------------------+------------------------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+------------------------------------------+
| mysql-bin.000004 | 1321 | | | dff98809-55c3-11e9-a58b-000c2928f5dd:1-6 |
+------------------+----------+--------------+------------------+------------------------------------------+
1 row in set (0.00 sec)

2.8.3. 基于GTID进行查看binlog

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具备GTID后,截取查看某些事务日志:
--include-gtids
--exclude-gtids
mysqlbinlog --include-gtids='dff98809-55c3-11e9-a58b-000c2928f5dd:1-6' --exclude-gtids='dff98809-55c3-11e9-a58b-000c2928f5dd:4' /data/binlog/mysql-bin.000004

2.8.4 GTID的幂等性

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开启GTID后,MySQL恢复Binlog时,重复GTID的事务不会再执行了
就想恢复?怎么办?
--skip-gtids
mysqlbinlog --include-gtids='3ca79ab5-3e4d-11e9-a709-000c293b577e:4' /data/binlog/mysql-bin.000004 /data/binlog/mysql-bin.000004
set sql_log_bin=0;
source /tmp/binlog.sql
set sql_log_bin=1;

2.9 使用二进制日志恢复数据案例

2.9.1 故障环境介绍

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创建了一个库  db, 导入了表t1 ,t1表中录入了很多数据
一个开发人员,drop database db;
没有备份,日志都在.怎么恢复?
思路:找到建库语句到删库之前所有的日志,进行恢复.(开启了GTID模式)
故障案例模拟:
(0) drop database if exists db ;
(1) create database db charset utf8;
(2) use db;
(3) create table t1 (id int);
(4) insert into t1 values(1),(2),(3);
(5) insert into t1 values(4),(5),(6);
(6) commit
(7) update t1 set id=30 where id=3;
(8) commit;
(9) delete from t1 where id=4;
(10)commit;
(11)insert into t1 values(7),(8),(9);
(12)commit;
(13)drop database db;
========================
drop database if exists db ;
create database db charset utf8;
use db;
create table t1 (id int);
insert into t1 values(1),(2),(3);
insert into t1 values(4),(5),(6);
commit;
update t1 set id=30 where id=3;
commit;
delete from t1 where id=4;
commit;
insert into t1 values(7),(8),(9);
commit;
drop database db;
=======
运行以上语句,模拟故障场景
需求:将数据库恢复到以下状态(提示第9步和第13步是误操作,其他都是正常操作)

2.9.2 恢复过程(无GTID时的恢复)

  1. 查看当前使用的 binlog文件
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oldguo [db]>show master status ;
+------------------+----------+--------------+------------------+-------------------+

| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |

+------------------+----------+--------------+------------------+-------------------+

| mysql-bin.000006 | 1873 | | | |

+------------------+----------+--------------+------------------+-------------------+

2.查看事件:

第一段:
| mysql-bin.000006 | 813 | Query | 1 | 907 | use `db`; create table t1 (id int) |

| mysql-bin.000006 | 907 | Query | 1 | 977 | BEGIN |

| mysql-bin.000006 | 977 | Table_map | 1 | 1020 | table_id: 77 (db.t1) |

| mysql-bin.000006 | 1020 | Write_rows | 1 | 1070 | table_id: 77 flags: STMT_END_F |

| mysql-bin.000006 | 1070 | Table_map | 1 | 1113 | table_id: 77 (db.t1) |

| mysql-bin.000006 | 1113 | Write_rows | 1 | 1163 | table_id: 77 flags: STMT_END_F |

| mysql-bin.000006 | 1163 | Xid | 1 | 1194 | COMMIT /* xid=74 */ |

| mysql-bin.000006 | 1194 | Query | 1 | 1264 | BEGIN |

| mysql-bin.000006 | 1264 | Table_map | 1 | 1307 | table_id: 77 (db.t1) |

| mysql-bin.000006 | 1307 | Update_rows | 1 | 1353 | table_id: 77 flags: STMT_END_F |

| mysql-bin.000006 | 1353 | Xid | 1 | 1384 | COMMIT /* xid=77 */

mysqlbinlog --start-position=813 --stop-position=1384 /data/mysql/mysql-bin.000006 >/tmp/bin1.sql

第二段:

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| mysql-bin.000006 | 1568 | Query      |        1 |        1638 | BEGIN                                              |

| mysql-bin.000006 | 1638 | Table_map | 1 | 1681 | table_id: 77 (db.t1) |

| mysql-bin.000006 | 1681 | Write_rows | 1 | 1731 | table_id: 77 flags: STMT_END_F |

| mysql-bin.000006 | 1731 | Xid | 1 | 1762 | COMMIT /* xid=81 */

mysqlbinlog --start-position=1568 --stop-position=1762 /data/mysql/mysql-bin.000006 >/tmp/bin2.sql

3.恢复

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set sql_log_bin=0;
source /tmp/bin1.sql
source /tmp/bin2.sql
set sql_log_bin=1;
oldguo [db]>select * from t1;

+------+

| id |

+------+

| 1 |

| 2 |

| 30 |

| 4 |

| 5 |

| 6 |

| 7 |

| 8 |

| 9 |

2.9.3 有GTID的恢复:

(1)截取

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mysqlbinlog --skip-gtids --include-gtids='3ca79ab5-3e4d-11e9-a709-000c293b577e:7-12' mysql-bin.000004> /tmp/bin.sql

(2)恢复

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set sql_log_bin=0;
source /tmp/bin.sql

2.10二进制日志其他操作

2.10.1 自动清理日志

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show variables like '%expire%';
expire_logs_days 0
自动清理时间,是要按照全备周期+1
set global expire_logs_days=8;
永久生效:
my.cnf
expire_logs_days=15;
企业建议,至少保留两个全备周期+1的binlog

2.10.2 手工清理

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PURGE BINARY LOGS BEFORE now() - INTERVAL 3 day;
PURGE BINARY LOGS TO 'mysql-bin.000010';
注意:不要手工 rm binlog文件
1. my.cnf binlog关闭掉,启动数据库
2.把数据库关闭,开启binlog,启动数据库
删除所有binlog,并从000001开始重新记录日志

*reset master; 主从关系中,主库执行此操作,主从环境必崩

2.10.3 日志是怎么滚动

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flush logs; 
重启mysql也会自动滚动一个新的
日志文件达到1G大小(max_binlog_size)
| max_binlog_size | 1073741824
备份时,加入参数也可以自动滚动

3.slow_log 慢日志

3.1 作用:

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3.2 开启慢日志(默认没开启)

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开关:
slow_query_log=1
文件位置及名字
slow_query_log_file=/data/mysql/slow.log
设定慢查询时间:
long_query_time=0.1
没走索引的语句也记录:
log_queries_not_using_indexes
vim /etc/my.cnf
slow_query_log=1
slow_query_log_file=/data/mysql/slow.log
long_query_time=0.1
log_queries_not_using_indexes
systemctl restart mysqld

3.3 mysqldumpslow 分析慢日志

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mysqldumpslow -s c -t 10 /data/mysql/slow.log

# 第三方工具(自己扩展)
https://www.percona.com/downloads/percona-toolkit/LATEST/
yum install perl-DBI perl-DBD-MySQL perl-Time-HiRes perl-IO-Socket-SSL perl-Digest-MD5
toolkit工具包中的命令:
./pt-query-diagest /data/mysql/slow.log
Anemometer基于pt-query-digest将MySQL慢查询可视化

作者:wwwoldguocom
链接:https://www.jianshu.com/p/00c54d2832ed
来源:简书
著作权归作者所有。商业转载请联系作者获得授权,非商业转载请注明出处。

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