MySQL 5.6 已经支持延迟的流复制， 可设置备节点的延迟时间， 延迟复制是有意义的，例如防止主节点数据误删，查看数据库历史状态等。
重点：延迟复制实在原有的主从复制基础上、所以先要有主从复制的环境，然后配置延迟复制.
一、 语法：
|
1
|
CHANGE MASTER
TO
MASTER_DELAY = 30;
---表示延迟30s
|
备注：设置备节点延迟的时间，单位秒。
二、 配置延迟复制
登录从节点服务器进行设置：
|
1
2
3
4
5
6
|
root@localhost:mysql>stop slave;
Query OK, 0
rows
affected (0.21 sec)
root@localhost:mysql>CHANGE MASTER
TO
MASTER_DELAY = 30;
Query OK, 0
rows
affected (0.17 sec)
root@localhost:mysql>start slave;
Query OK, 0
rows
affected (0.27 sec)
|
三、查看从节点状态
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
|
root@localhost:mysql>
select
*
from
slave_relay_log_info\G
*************************** 1. row ***************************
Number_of_lines: 7
Relay_log_name: ./db2-relay-bin.000007
Relay_log_pos: 281
Master_log_name: bin-log.000041
Master_log_pos: 361
Sql_delay: 30
Number_of_workers: 0
Id: 1
1 row
in
set
(0.00 sec)
root@localhost:mysql>show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting
for
master
to
send event
Master_Host: 192.168.2.37
Master_User: rep1
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: bin-log.000040
Read_Master_Log_Pos: 604
Relay_Log_File: db2-relay-bin.000002
Relay_Log_Pos: 281
Relay_Master_Log_File: bin-log.000040
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 604
Relay_Log_Space: 452
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed:
No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert:
No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 1
Master_UUID: 0c130d47-22bb-11e4-aaaa-000c2986ac80
Master_Info_File: mysql.slave_master_info
SQL_Delay: 30
SQL_Remaining_Delay:
NULL
Slave_SQL_Running_State: Slave has
read
all
relay log; waiting
for
the slave I/O thread
to
update
it
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
1 row
in
set
(0.00 sec)
|
四、主节点创建表测试
|
1
2
3
4
5
|
root@localhost:mysql>
create
table
test_delay(id int4
primary
key
,
create_time datetime
default
current_timestamp
);
Query OK, 0
rows
affected (0.59 sec)
root@localhost:mysql>
insert
into
test_delay (id)
values
(1);
Query OK, 1 row affected (0.07 sec)
|
五、备节点查询
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
root@localhost:mysql>
select
*
from
test_delay;
Empty
set
(0.00 sec)
root@localhost:mysql>
select
*
from
test_delay;
Empty
set
(0.00 sec)
这时在备节点上还查不到表。
root@localhost:mysql>show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting
for
master
to
send event
Master_Host: 192.168.2.37
Master_User: rep1
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: bin-log.000040
Read_Master_Log_Pos: 1013
Relay_Log_File: db2-relay-bin.000002
Relay_Log_Pos: 281
Relay_Master_Log_File: bin-log.000040
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 604
Relay_Log_Space: 861
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed:
No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 15
Master_SSL_Verify_Server_Cert:
No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 1
Master_UUID: 0c130d47-22bb-11e4-aaaa-000c2986ac80
Master_Info_File: mysql.slave_master_info
SQL_Delay: 30
SQL_Remaining_Delay: 14
Slave_SQL_Running_State: Waiting until MASTER_DELAY seconds
after
master executed event
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
1 row
in
set
(0.00 sec)
root@localhost:mysql>
select
*
from
test_delay;
+
----+---------------------+
| id | create_time |
+
----+---------------------+
| 1 | 2014-12-12 14:38:47 |
+
----+---------------------+
1 row
in
set
(0.00 sec)
|
六、备注: 发现备节点在 30 秒后才能查到新建的表，这里有三个字段显示延迟的信息：
SQL_Delay: 显示已设置的主备延迟的时间，单位秒;
SQL_Remaining_Delay: 显示剩余的主备延迟时间，单位秒;
Slave_SQL_Running_State: 表示 SQL thread 状态;
本文转自crazy_charles 51CTO博客，原文链接：http://blog.51cto.com/douya/1786980，如需转载请自行联系原作者
