mysql日志介绍「建议收藏」

云烟 • 2023年 5月 24日上午10:00 • 未分类 • 阅读 271

欢迎大家来到IT世界,在知识的湖畔探索吧!

错误日志(log_error)

–记录启动\关闭\日常运行过程中,状态信息,警告,错误

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.cnflog_error=/var/log/mysql.loglog_timestamps=system重启生效show variables like 'log_error';

欢迎大家来到IT世界,在知识的湖畔探索吧!

默认位置：

DATADIR/hostname.err

配置方式

vim .etc/my.cnf

log_error=/data/mysql/data/mysql.log

查看：

欢迎大家来到IT世界,在知识的湖畔探索吧!mysql> select @@log_error;+----------------------+| @@log_error          |+----------------------+| /data/3307/mysql.log |+----------------------+1 row in set (0.00 sec)

binlog(binary logs):二进制日志 *****

(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

binlog配置 (5.7必须加server_id)

欢迎大家来到IT世界,在知识的湖畔探索吧!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;

log_error=/data/mysql/data/mysql.log
log_bin=/data/binlog/3306/mysql-bin #/data/binlog/3306/ ：目录 mysql-bin：文件名

[root@localhost 3306]# pwd/data/binlog/3306[root@localhost 3306]# ll总用量 8-rw-r----- 1 mysql mysql 154 9月   4 13:51 mysql-bin.000001-rw-r----- 1 mysql mysql  35 9月   4 13:51 mysql-bin.index

查看配置

mysql> show variables like '%log_bin%';+---------------------------------+-----------------------------------+| Variable_name                   | Value                             |+---------------------------------+-----------------------------------+| log_bin                         | ON                                || log_bin_basename                | /data/binlog/3306/mysql-bin       || log_bin_index                   | /data/binlog/3306/mysql-bin.index || log_bin_trust_function_creators | OFF                               || log_bin_use_v1_row_events       | OFF                               || sql_log_bin                     | ON                                |+---------------------------------+-----------------------------------+6 rows in set (0.00 sec)

binlog记录了什么?

—–binlog是SQL层的功能。记录的是变更SQL语句，不记录查询语句。

记录SQL语句种类

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

DML三种记录方式binlog_format（binlog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

mysql> show variables like 'bnlog_format';+---------------+-------+| Variable_name | Value |+---------------+-------+| binlog_format | ROW   |+---------------+-------+1 row in set (0.00 sec)

面试题

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    intimeinsert into t1 values(1,'zs',now())我们建议使用：row记录模式

event（事件）是什么?

事件的简介

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4个event
begin; 120 – 340
DML1 340 – 460
DML2 460 – 550
commit; 550 – 760

event的组成

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

查看一共多少个binlog

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)]>

通过执行flush logs命令之后，再次查询binary log信息，发现已经使用了一个新的bin log文件了。
flush logs命令的作用就是关闭当前使用的binary log，然后打开一个新的binary log文件，binlog文件的序号递增加1

查看mysql正在使用的日志文件

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

日志内容查看

event查看

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

binlog文件内容详细查看

mysqlbinlog /data/mysql/mysql-bin.000006mysqlbinlog --base64-output=decode-rows -vvv /data/binlog/mysql-bin.000003mysqlbinlog  -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

基于Position号进行日志截取

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;#设为0后，在Master数据库上执行的语句临时都不记录binlog，退出窗口可以恢复[(none)]>source /tmp/bin.sql

-----上述通过pos位置恢复 需要关闭gitd----经过测试发现 开起来gitd，通过pos位置无法恢复数据

mysqlbinlog --start-position=219 --stop-position=1012 /data/binlog/3306/mysql-bin.000002 >/tmp/bin.sql

binlog日志的GTID新特性

GTID 介绍

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’

GTID(Global Transaction ID)

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：

vim /etc/my.cnfgtid-mode=onenforce-gtid-consistency=truesystemctl restart mysqldMaster [(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 gtidDatabase changedMaster [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)

基于GTID进行查看binlog

具备GTID后,截取查看某些事务日志:--include-gtids--exclude-gtidsmysqlbinlog --include-gtids='dff98809-55c3-11e9-a58b-000c2928f5dd:1-6' --exclude-gtids='dff98809-55c3-11e9-a58b-000c2928f5dd:4'  /data/binlog/mysql-bin.000004跳过多个事务idmysqlbinlog --include-gtids='dff98809-55c3-11e9-a58b-000c2928f5dd:1-6' --exclude-gtids='dff98809-55c3-11e9-a58b-000c2928f5dd:4,dff98809-55c3-11e9-a58b-000c2928f5dd:5'  /data/binlog/mysql-bin.000004

GTID的幂等性

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-gtidsmysqlbinlog --skip-gtids --include-gtids='3ca79ab5-3e4d-11e9-a709-000c293b577e:4' /data/binlog/mysql-bin.000004 > /tmp/binlog.sqlset sql_log_bin=0;source /tmp/binlog.sqlset sql_log_bin=1;

使用二进制日志恢复数据案例

故障环境介绍

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）

恢复过程(无GTID时的恢复)

1，查看当前使用的 binlog文件

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：

| 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

set sql_log_bin=0;source /tmp/bin1.sqlsource /tmp/bin2.sqlset sql_log_bin=1;oldguo [db]>select * from t1;+------+| id  |+------+|    1 ||    2 ||  30 ||    4 ||    5 ||    6 ||    7 ||    8 ||    9 |

有GTID的恢复:

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

恢复

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

二进制日志其他操作

自动清理日志

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

手工清理（危险）

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

日志是怎么滚动

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

slow_log 慢日志

记录慢SQL语句的日志,定位低效SQL语句的工具日志

mysql> show variables like '%slow%';+---------------------------+-------------------------------------+| Variable_name             | Value                               |+---------------------------+-------------------------------------+| log_slow_admin_statements | OFF                                 || log_slow_slave_statements | OFF                                 || slow_launch_time          | 2                                   || slow_query_log            | ON                                  || slow_query_log_file       | /data/mysql/data/localhost-slow.log |+---------------------------+-------------------------------------+5 rows in set (0.00 sec)

开启慢日志(默认没开启)

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 #不走索引vim /etc/my.cnfslow_query_log=1 slow_query_log_file=/data/mysql/slow.loglong_query_time=0.1log_queries_not_using_indexessystemctl restart mysqld

mysqldumpslow 分析慢日志

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-MD5toolkit工具包中的命令:./pt-query-diagest  /data/mysql/slow.logAnemometer基于pt-query-digest将MySQL慢查询可视化

常用的参数
-s：是表示按照何种方式排序

参数值	说明
c	访问计数
l	锁定时间
r	返回记录
t	查询时间
al	平均锁定时间
ar	平均返回记录数
at	平均查询时间

-t：是top n的意思，即为返回前面多少条的数据
-g：后边可以写一个正则匹配模式，大小写不敏感的

Mysql慢查询日志分析及percona-toolkit的使用