mysql exec time_MySQL Replication--复制延迟02--exec_time测试

复制延迟(Seconds_Behind_Master)测试

测试环境： MySQL 5.7.19

测试主从时间差：

检查主从系统时间差，同时在主库和从库执行SELECT NOW()语句：

主库：2019-06-24 10:57:56从库：2019-06-24 10:58:10从库比主库提前14秒，主从时间差14秒。

在主库上执行(使用基于语句格式复制)：

selectnow();

update tb003set c1=SLEEP(20) where id=1;select now();

主库上上执行效果：

mysql> selectnow();+---------------------+

| now() |

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

| 2019-06-24 11:01:54 |

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

1 row in set (0.00sec)

mysql> update tb003 set c1=SLEEP(20) where id=1;

Query OK,1 row affected, 1 warning (20.06sec)

Rows matched:1 Changed: 1 Warnings: 1mysql> selectnow();+---------------------+

| now() |

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

| 2019-06-24 11:02:14 |

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

1 row in set (0.00 sec)

主库上生成的binlog解析结果:

#190624 11:01:54 server id 1614520 end_log_pos 259 CRC32 0xcf2313f1 GTID last_committed=0 sequence_number=1 rbr_only=no

SET @@SESSION.GTID_NEXT= '025fd638-89ea-11e9-a749-40f2e9cf3aaa:9'/*!*/;

# at259#190624 11:01:54 server id 1614520 end_log_pos 340 CRC32 0xa14a2bcb Query thread_id=3186 exec_time=20 error_code=0SET TIMESTAMP=1561345314/*!*/;BEGIN/*!*/;

# at340#190624 11:01:54 server id 1614520 end_log_pos 456 CRC32 0xc283c9af Query thread_id=3186 exec_time=20 error_code=0use `db001`/*!*/;

SET TIMESTAMP=1561345314/*!*/;

update tb003set c1=SLEEP(20) where id=1

/*!*/;

# at456#190624 11:01:54 server id 1614520 end_log_pos 487 CRC32 0x0f3bdc57 Xid = 10020COMMIT/*!*/;

从库上relay log解析结果：

BINLOG '+zwQXQ+4ohgAdwAAAAAAAAAgAAQANS43LjE5LWxvZwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

AAAAAAAAAAAAAAAAAAAAAAAAEzgNAAgAEgAEBAQEEgAAXwAEGggAAAAICAgCAAAACgoKKioAEjQA

Af0UlBk=

'/*!*/;

# at 313#190624 11:01:54 server id 1614520 end_log_pos 259 CRC32 0xcf2313f1 GTID last_committed=0 sequence_number=1 rbr_only=no

SET @@SESSION.GTID_NEXT= '025fd638-89ea-11e9-a749-40f2e9cf3aaa:9'/*!*/;

# at378#190624 11:01:54 server id 1614520 end_log_pos 340 CRC32 0xa14a2bcb Query thread_id=3186 exec_time=20 error_code=0SET TIMESTAMP=1561345314/*!*/;BEGIN/*!*/;

# at459#190624 11:01:54 server id 1614520 end_log_pos 456 CRC32 0xc283c9af Query thread_id=3186 exec_time=20 error_code=0use `db001`/*!*/;

SET TIMESTAMP=1561345314/*!*/;

update tb003set c1=SLEEP(20) where id=1

/*!*/;

# at575#190624 11:01:54 server id 1614520 end_log_pos 487 CRC32 0x0f3bdc57 Xid = 10020COMMIT/*!*/;

从库上生成binlog解析结果(从库上默认binlog_format=row)：

#190624 11:01:54 server id 1614520 end_log_pos 259 CRC32 0x6e1a971f GTID last_committed=0 sequence_number=1 rbr_only=yes/*!50718 SET TRANSACTION ISOLATION LEVEL READ COMMITTED*//*!*/;

SET @@SESSION.GTID_NEXT= '025fd638-89ea-11e9-a749-40f2e9cf3aaa:9'/*!*/;

# at259#190624 11:01:54 server id 1614520 end_log_pos 332 CRC32 0x063cd6ca Query thread_id=3186 exec_time=54 error_code=0SET TIMESTAMP=1561345314/*!*/;BEGIN/*!*/;

# at332#190624 11:01:54 server id 1614520 end_log_pos 396 CRC32 0x405b61c7Rows_query

# update tb003set c1=SLEEP(20) where id=1# at396#190624 11:01:54 server id 1614520 end_log_pos 448 CRC32 0x015803f1 Table_map: `db001`.`tb003` mapped to number 232# at448#190624 11:01:54 server id 1614520 end_log_pos 518 CRC32 0xb59069f9 Update_rows: table id 232flags: STMT_END_F

BINLOG'Ij0QXR24ohgAQAAAAIwBAACAACh1cGRhdGUgdGIwMDMgc2V0IGMxPVNMRUVQKDIwKSB3aGVyZSBp

ZD0xx2FbQA==Ij0QXRO4ohgANAAAAMABAAAAAOgAAAAAAAEABWRiMDAxAAV0YjAwMwADCAMRAQAC8QNYAQ==Ij0QXR+4ohgARgAAAAYCAAAAAOgAAAAAAAEAAgAD///4AQAAAAAAAAABAAAAXRA89fgBAAAAAAAA

AAAAAABdED0i+WmQtQ==

'/*!*/;

### UPDATE `db001`.`tb003`

### WHERE

### @1=1 /*LONGINT meta=0 nullable=0 is_null=0*/### @2=1 /*INT meta=0 nullable=1 is_null=0*/### @3=1561345269 /*TIMESTAMP(0) meta=0 nullable=0 is_null=0*/### SET

### @1=1 /*LONGINT meta=0 nullable=0 is_null=0*/### @2=0 /*INT meta=0 nullable=1 is_null=0*/### @3=1561345314 /*TIMESTAMP(0) meta=0 nullable=0 is_null=0*/# at518#190624 11:01:54 server id 1614520 end_log_pos 549 CRC32 0xae037515 Xid = 6241COMMIT/*!*/;

无论时主库binlog事件中还是从库relaylog事件以及从库binlog事件中记录的时间都是事务语句执行开始时间：

SET TIMESTAMP=1561345314/*!*/;

SELECT FROM_UNIXTIME(1561345314);+---------------------------+

| FROM_UNIXTIME(1561345314) |

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

| 2019-06-24 11:01:54 |

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

exec_time计算：The time from when the query started to when it was logged in the binlog, in seconds.

1、由于SQL语句中使用函数SLEEP(20),因此SQL语句执行时间=SLEEP(20)的执行时间+UPDATE操作的执行时间，而UPDATE操作的执行时间在10ms以内，因此整个SQL语句在主库的执行时间=20S，因此主库binlog的中记录exec_time=20

2、从库的relaylog用来存放主库传递过来的binlog，因此从库relaylog与主库binlog相同，从库relaylog中记录也是exec_time=20

3、由于主库使用binlog_format=statement的复制格式，因此SQL语句被传递到从库并原样执行，同样执行需要20S，但该语句在主库的开始执行时间(the query started)为2019-06-24 11:01:54，而在从库执行结束时间(log in binlog)为2019-06-24 11:02:48，因此从库binlog中记录时间exec_time=54,忽略主从事务日志落盘和网络传输时间，exec_time=54S=主库语句执行时间(20)+从库语句执行时间(20S)+主从时间差(14S)。

在主库上执行(使用基于行格式复制)：

mysql> selectnow();+---------------------+

| now() |

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

| 2019-06-25 08:40:05 |

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

1 row in set (0.00sec)

mysql> update tb003 set c1=SLEEP(20) where id in (3,4);

Query OK,2 rows affected (40.04sec)

Rows matched:2 Changed: 2 Warnings: 0mysql> selectnow();+---------------------+

| now() |

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

| 2019-06-25 08:40:45 |

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

1 row in set (0.00 sec)

产生的binlog解析结果为：

# at 549#190625 8:40:05 server id 1614520 end_log_pos 614 CRC32 0x037e9b24 GTID last_committed=1 sequence_number=2 rbr_only=yes/*!50718 SET TRANSACTION ISOLATION LEVEL READ COMMITTED*//*!*/;

SET @@SESSION.GTID_NEXT= '025fd638-89ea-11e9-a749-40f2e9cf3aaa:65'/*!*/;

# at614#190625 8:40:05 server id 1614520 end_log_pos 687 CRC32 0xe186daee Query thread_id=837 exec_time=20 error_code=0SET TIMESTAMP=1561423205/*!*/;

BEGIN/*!*/;

# at687#190625 8:40:05 server id 1614520 end_log_pos 758 CRC32 0x9f76a54aRows_query

# update tb003set c1=SLEEP(20) where id in (3,4)

# at758#190625 8:40:05 server id 1614520 end_log_pos 810 CRC32 0x139892d9 Table_map: `db001`.`tb003` mapped to number 108# at810#190625 8:40:05 server id 1614520 end_log_pos 914 CRC32 0xf7980c93 Update_rows: table id 108flags: STMT_END_F

BINLOG'ZW0RXR24ohgARwAAAPYCAACAAC91cGRhdGUgdGIwMDMgc2V0IGMxPVNMRUVQKDIwKSB3aGVyZSBp

ZCBpbiAoMyw0KUqldp8=ZW0RXRO4ohgANAAAACoDAAAAAGwAAAAAAAEABWRiMDAxAAV0YjAwMwADCAMRAQAC2ZKYEw==ZW0RXR+4ohgAaAAAAJIDAAAAAGwAAAAAAAEAAgAD///4AwAAAAAAAAABAAAAXRFrW/gDAAAAAAAA

AAAAAABdEW1l+AQAAAAAAAAAAQAAAF0Ra1v4BAAAAAAAAAAAAAAAXRFtZZMMmPc=

'/*!*/;

### UPDATE `db001`.`tb003`

### WHERE

### @1=3 /*LONGINT meta=0 nullable=0 is_null=0*/### @2=1 /*INT meta=0 nullable=1 is_null=0*/### @3=1561422683 /*TIMESTAMP(0) meta=0 nullable=0 is_null=0*/### SET

### @1=3 /*LONGINT meta=0 nullable=0 is_null=0*/### @2=0 /*INT meta=0 nullable=1 is_null=0*/### @3=1561423205 /*TIMESTAMP(0) meta=0 nullable=0 is_null=0*/### UPDATE `db001`.`tb003`

### WHERE

### @1=4 /*LONGINT meta=0 nullable=0 is_null=0*/### @2=1 /*INT meta=0 nullable=1 is_null=0*/### @3=1561422683 /*TIMESTAMP(0) meta=0 nullable=0 is_null=0*/### SET

### @1=4 /*LONGINT meta=0 nullable=0 is_null=0*/### @2=0 /*INT meta=0 nullable=1 is_null=0*/### @3=1561423205 /*TIMESTAMP(0) meta=0 nullable=0 is_null=0*/# at914#190625 8:40:05 server id 1614520 end_log_pos 945 CRC32 0x1f65c801 Xid = 2610COMMIT/*!*/;

在主库上执行(使用基于行格式复制+两条语句组合事务操作)：

mysql> selectnow();+---------------------+

| now() |

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

| 2019-06-25 08:55:56 |

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

1 row in set (0.00sec)

mysql>begin;

Query OK,0 rows affected (0.00sec)

mysql> update tb003 set c1=SLEEP(20) where id =5;

Query OK,1 row affected (20.00sec)

Rows matched:1 Changed: 1 Warnings: 0mysql> update tb003 set c1=SLEEP(20) where id =6;

Query OK,1 row affected (20.00sec)

Rows matched:1 Changed: 1 Warnings: 0mysql>commit;

Query OK,0 rows affected (0.05sec)

mysql> selectnow();+---------------------+

| now() |

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

| 2019-06-25 08:56:36 |

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

1 row in set (0.00 sec)

产生的binlog解析结果为：

# at 945#190625 8:56:36 server id 1614520 end_log_pos 1010 CRC32 0x5a8cb5f0 GTID last_committed=2 sequence_number=3 rbr_only=yes/*!50718 SET TRANSACTION ISOLATION LEVEL READ COMMITTED*//*!*/;

SET @@SESSION.GTID_NEXT= '025fd638-89ea-11e9-a749-40f2e9cf3aaa:66'/*!*/;

# at1010#190625 8:55:56 server id 1614520 end_log_pos 1083 CRC32 0x5217a928 Query thread_id=838 exec_time=20 error_code=0SET TIMESTAMP=1561424156/*!*/;

BEGIN/*!*/;

# at1083#190625 8:55:56 server id 1614520 end_log_pos 1148 CRC32 0x1a70cac7Rows_query

# update tb003set c1=SLEEP(20) where id =5# at1148#190625 8:55:56 server id 1614520 end_log_pos 1200 CRC32 0x4cf6d8c7 Table_map: `db001`.`tb003` mapped to number 108# at1200#190625 8:55:56 server id 1614520 end_log_pos 1270 CRC32 0x033f26f8 Update_rows: table id 108flags: STMT_END_F

BINLOG'HHERXR24ohgAQQAAAHwEAACAACl1cGRhdGUgdGIwMDMgc2V0IGMxPVNMRUVQKDIwKSB3aGVyZSBp

ZCA9NcfKcBo=HHERXRO4ohgANAAAALAEAAAAAGwAAAAAAAEABWRiMDAxAAV0YjAwMwADCAMRAQACx9j2TA==HHERXR+4ohgARgAAAPYEAAAAAGwAAAAAAAEAAgAD///4BQAAAAAAAAABAAAAXRDBV/gFAAAAAAAA

AAAAAABdEXEc+CY/Aw==

'/*!*/;

### UPDATE `db001`.`tb003`

### WHERE

### @1=5 /*LONGINT meta=0 nullable=0 is_null=0*/### @2=1 /*INT meta=0 nullable=1 is_null=0*/### @3=1561379159 /*TIMESTAMP(0) meta=0 nullable=0 is_null=0*/### SET

### @1=5 /*LONGINT meta=0 nullable=0 is_null=0*/### @2=0 /*INT meta=0 nullable=1 is_null=0*/### @3=1561424156 /*TIMESTAMP(0) meta=0 nullable=0 is_null=0*/# at1270#190625 8:56:16 server id 1614520 end_log_pos 1335 CRC32 0x3b3202faRows_query

# update tb003set c1=SLEEP(20) where id =6# at1335#190625 8:56:16 server id 1614520 end_log_pos 1387 CRC32 0x8b013c05 Table_map: `db001`.`tb003` mapped to number 108# at1387#190625 8:56:16 server id 1614520 end_log_pos 1457 CRC32 0xf7d67996 Update_rows: table id 108flags: STMT_END_F

BINLOG'MHERXR24ohgAQQAAADcFAACAACl1cGRhdGUgdGIwMDMgc2V0IGMxPVNMRUVQKDIwKSB3aGVyZSBp

ZCA9NvoCMjs=MHERXRO4ohgANAAAAGsFAAAAAGwAAAAAAAEABWRiMDAxAAV0YjAwMwADCAMRAQACBTwBiw==MHERXR+4ohgARgAAALEFAAAAAGwAAAAAAAEAAgAD///4BgAAAAAAAAABAAAAXRB9NvgGAAAAAAAA

AAAAAABdEXEwlnnW9w==

'/*!*/;

### UPDATE `db001`.`tb003`

### WHERE

### @1=6 /*LONGINT meta=0 nullable=0 is_null=0*/### @2=1 /*INT meta=0 nullable=1 is_null=0*/### @3=1561361718 /*TIMESTAMP(0) meta=0 nullable=0 is_null=0*/### SET

### @1=6 /*LONGINT meta=0 nullable=0 is_null=0*/### @2=0 /*INT meta=0 nullable=1 is_null=0*/### @3=1561424176 /*TIMESTAMP(0) meta=0 nullable=0 is_null=0*/# at1457#190625 8:56:36 server id 1614520 end_log_pos 1488 CRC32 0x8b074201 Xid = 2625COMMIT/*!*/;

可以发现上面两个操作都执行了40秒，但在事务开始前(BEGIN)的exec_time都仅为20,且事务内部单个操作没有exec_time。

ev->exec_time的计算在sql/log_event.cc中的代码如下：

/*

exec_time calculation has changed to use the same method that is used

to fill out "thd_arg->start_time"

*/

structtimeval end_time;

ulonglong micro_end_time=my_micro_time();

my_micro_time_to_timeval(micro_end_time, &end_time);

exec_time= end_time.tv_sec - thd_arg->start_time.tv_sec;

exec_time在文件sql/log_event.h中的注解如下：

exec_time4 byte unsigned integerThe time from when the query started to when it was logged inthe binlog, in seconds.