Mysql 5.6Master and Slave active / standby handoff 02/28 Update SLTechnology News&Howtos

Mysql 5.6Master and Slave active / standby handoff

2025-02-28 Update From: SLTechnology News&Howtos shulou NAV: SLTechnology News&Howtos > Database >

Shulou(Shulou.com)06/01 Report--

-- master/slave toggles records for later search

Environment:

Master:

Rhel 6.6

Mysql 5.6

192.168.15.101

Salve:

Rhel 7.2

Mysql 5.6

192.168.15.102

Key points for switching between master and slave libraries:

Main Library profile:

[root@rhel66db ~] # more / etc/my.cnf

[mysqld]

Port = 3306

Character_set_server=utf8

Character_set_client=utf8

Collation-server=utf8_general_ci

Lower_case_table_names=1

Max_connections=1000

Datadir=/usr/local/mysql

Socket=/tmp/mysql.sock

User=mysql

# Disabling symbolic-links is recommended to prevent assorted security risks

Symbolic-links=0

Server-id=101

Log-bin=mysql-bin

Auto_increment_increment=2

Auto_increment_offset=1

Binlog-ignore=mysql

Binlog-ignore=information_schema

Replicate-do-db=gaoyc

[mysqld_safe]

Log-error=/usr/local/mysql/mysqld.log

Pid-file=/usr/local/mysql/mysqld.pid

Prepare the library profile:

[root@rhel72 ~] # more / etc/my.cnf

[mysqld]

Port = 3306

Character_set_server=utf8

Character_set_client=utf8

Collation-server=utf8_general_ci

Lower_case_table_names=1

Max_connections=1000

Datadir=/usr/local/mysql

Socket=/tmp/mysql.sock

User=mysql

# Disabling symbolic-links is recommended to prevent assorted security risks

Symbolic-links=0

Server-id=102

Log-bin=mysql-bin

Auto_increment_increment=2

Auto_increment_offset=2

Binlog-ignore=mysql

Binlog-ignore=information_schema

Replicate-do-db=gaoyc

[mysqld_safe]

Log-error=/usr/local/mysql/mysqld.log

Pid-file=/usr/local/mysql/mysqld.pid

-- main library operation, configured as read-only

Mysql > set global read_only=1

Mysql > show variables like 'read%'

+-+ +

| | Variable_name | Value |

+-+ +

| | read_buffer_size | 131072 | |

| | read_only | ON |

| | read_rnd_buffer_size | 262144 | |

Check for updates

Mysql > SHOW MASTER STATUS

+-+ +

+-+ +

+-+ +

Mysql > SHOW MASTER STATUS

+-+ +

+-+ +

+-+ +

After confirming that there is no data change, go to the standby database operation:

-- prepare database operations:

Mysql > select user,host,password from mysql.user

+-- +

+-- +

| | root | 127.0.0.1 |

| | root |:: 1 |

+-- +

4 rows in set (0.00 sec)

Mysql > show processlist

+-+ -+

+-+ -+

+-+ -+

3 rows in set (0.00 sec)

Mysql > show processlist

+-+ -+

+-+ -+

+-+ -+

3 rows in set (0.00 sec)

After checking that the Slave has read all relay log is found, and after ensuring that all logs have been applied, stop replication.

Mysql > STOP SLAVE IO_THREAD

Query OK, 0 rows affected (0.00 sec)

Mysql > show slave status\ G

* * 1. Row *

Slave_IO_State:

Master_Host: 192.168.15.101

Master_User: mysql12

Master_Port: 3306

Connect_Retry: 60

Master_Log_File: mysql-bin.000005

Read_Master_Log_Pos: 2740

Relay_Log_File: rhel72-relay-bin.000003

Relay_Log_Pos: 283

Relay_Master_Log_File: mysql-bin.000005

Slave_IO_Running: No

Slave_SQL_Running: Yes

Replicate_Do_DB: gaoyc

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: 2740

Relay_Log_Space: 2248

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: NULL

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: 101

Master_UUID: 3e688040-3c80-11e8-a80a-0800275acb61

Master_Info_File: / usr/local/mysql/master.info

SQL_Delay: 0

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)

ERROR:

No query specified

Mysql > stop slave

Query OK, 0 rows affected (0.01 sec)

Mysql > show slave status\ G

* * 1. Row *

Slave_IO_State:

Master_Host: 192.168.15.101

Master_User: mysql12

Master_Port: 3306

Connect_Retry: 60

Master_Log_File: mysql-bin.000005

Read_Master_Log_Pos: 2740

Relay_Log_File: rhel72-relay-bin.000003

Relay_Log_Pos: 283

Relay_Master_Log_File: mysql-bin.000005

Slave_IO_Running: No

Slave_SQL_Running: No

Replicate_Do_DB: gaoyc

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: 2740

Relay_Log_Space: 2248

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: NULL

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: 101

Master_UUID: 3e688040-3c80-11e8-a80a-0800275acb61

Master_Info_File: / usr/local/mysql/master.info

SQL_Delay: 0

SQL_Remaining_Delay: NULL

Slave_SQL_Running_State:

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)

ERROR:

No query specified

Mysql > RESET MASTER

Query OK, 0 rows affected (0.02 sec)

Mysql > reset slave

Query OK, 0 rows affected (0.02 sec)

Mysql > GRANT REPLICATION SLAVE ON *. * TO 'mysql12'@'192.168.15.101' IDENTIFIED BY' mysql12'

Query OK, 0 rows affected (0.00 sec)

Mysql > FLUSH PRIVILEGES

Query OK, 0 rows affected (0.00 sec)

Mysql > select user,host,password from mysql.user

+-- +

+-- +

| | root | 127.0.0.1 |

| | root |:: 1 |

+-- +

5 rows in set (0.00 sec)

Mysql > quit

Bye

[root@rhel72 local] # ps-ef | grep mysql

Root 5789 10 02:04 pts/0 00:00:00 / bin/sh / usr/local/mysql/bin/mysqld_safe-- datadir=/usr/local/mysql-- pid-file=/usr/local/mysql/rhel72.pid

Mysql 6112 5789 0 02:04 pts/0 00:00:10 / usr/local/mysql/bin/mysqld-basedir=/usr/local/mysql-datadir=/usr/local/mysql-plugin-dir=/usr/local/mysql/lib/plugin-user=mysql-log-error=/usr/local/mysql/mysqld.log-pid-file=/usr/local/mysql/rhel72.pid-socket=/tmp/mysql.sock-port=3306

Root 6174 2877 0 02:18 pts/1 00:00:00 tail-30f mysqld.log

Root 8263 2195 0 04:29 pts/0 00:00:00 grep-color=auto mysql

[root@rhel72 local] # kill-9 6112 5789

[root@rhel72 local] # pwd

/ usr/local

[root@rhel72 local] #. / mysql.server start

Starting MySQL SUCCESS!

[root@rhel72 local] # mysql-uroot-pgyc1234

Warning: Using a password on the command line interface can be insecure.

Welcome to the MySQL monitor. Commands end with; or\ g.

Your MySQL connection id is 1

Server version: 5.6.38-enterprise-commercial-advanced-log MySQL Enterprise Server-Advanced Edition (Commercial)

Oracle is a registered trademark of Oracle Corporation and/or its

Affiliates. Other names may be trademarks of their respective

Owners.

Type 'help;' or'\ h' for help. Type'\ c'to clear the current input statement.

Mysql > select user,host,password from mysql.user

+-- +

+-- +

| | root | 127.0.0.1 |

| | root |:: 1 |

+-- +

5 rows in set (0.00 sec)

Mysql > show master status

+-+ +

+-+ +

+-+ +

1 row in set (0.00 sec)

-- the operation of the original master database

Mysql > set global read_only=0

Query OK, 0 rows affected (0.00 sec)

Mysql > show variables like 'read%'

+-+ +

| | Variable_name | Value |

+-+ +

| | read_buffer_size | 131072 | |

| | read_only | OFF |

| | read_rnd_buffer_size | 262144 | |

+-+ +

3 rows in set (0.00 sec)

Mysql > RESET MASTER

Query OK, 0 rows affected (0.03 sec)

Mysql > show master status

+-+ +

+-+ +

+-+ +

1 row in set (0.00 sec)

Mysql > CHANGE MASTER TO

-> MASTER_HOST='192.168.15.102'

-> MASTER_USER='mysql12'

-> MASTER_PASSWORD='mysql12'

-> MASTER_LOG_FILE='mysql-bin.000002'

-> MASTER_LOG_POS=120

ERROR 1198 (HY000): This operation cannot be performed with a running slave; run STOP SLAVE first

Mysql > stop slave

Query OK, 0 rows affected (0.00 sec)

Mysql > CHANGE MASTER TO

-> MASTER_HOST='192.168.15.102'

-> MASTER_USER='mysql12'

-> MASTER_PASSWORD='mysql12'

-> MASTER_LOG_FILE='mysql-bin.000002'

-> MASTER_LOG_POS=120

Query OK, 0 rows affected, 2 warnings (0.02 sec)

Mysql > start slave

Query OK, 0 rows affected (0.01 sec)

Mysql > show slave status\ G

* * 1. Row *

Slave_IO_State: Waiting for master to send event

Master_Host: 192.168.15.102

Master_User: mysql12

Master_Port: 3306

Connect_Retry: 60

Master_Log_File: mysql-bin.000002

Read_Master_Log_Pos: 120

Relay_Log_File: mysqld-relay-bin.000002

Relay_Log_Pos: 283

Relay_Master_Log_File: mysql-bin.000002

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

Replicate_Do_DB: gaoyc

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: 120

Relay_Log_Space: 457

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: 102

Master_UUID: 81add948-3c6e-11e8-a796-08002706db9b

Master_Info_File: / usr/local/mysql/master.info

SQL_Delay: 0

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)

ERROR:

No query specified

-- Verification

# # main Library

Mysql > ues gaoyc

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 'ues gaoyc' at line 1

Mysql > use gaoyc

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

Mysql > insert into gyc01 select * from gyc01

Query OK, 80 rows affected (0.01sec)

Records: 80 Duplicates: 0 Warnings: 0

# prepare the library

Mysql > use gaoyc

Database changed

Mysql > show tables

+-+

| | Tables_in_gaoyc |

+-+

| | gyc |

| | gyc01 |

| | tab1 |

+-+

3 rows in set (0.00 sec)

Mysql > select count (*) from gyc01

+-+

| | count (*) |

+-+

| | 80 |

+-+

1 row in set (0.00 sec)

Mysql > select count (*) from gyc01

+-+

| | count (*) |

+-+

| | 160 |

+-+

1 row in set (0.00 sec)

Description of slave status parameters

Mysql > show slave status\ G

* * 1. Row *

Slave_IO_State: Waiting for master to send event

Master_Host: 192.168.15.101

Master_User: mysql12

Master_Port: 3306

Connect_Retry: 60

Master_Log_File: mysql-bin.000005

Read_Master_Log_Pos: 2264

Relay_Log_File: rhel72-relay-bin.000002

Relay_Log_Pos: 1435

Relay_Master_Log_File: mysql-bin.000005

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

Replicate_Do_DB: gaoyc

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: 2264

Relay_Log_Space: 1609

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: 101

Master_UUID: 3e688040-3c80-11e8-a80a-0800275acb61

Master_Info_File: / usr/local/mysql/master.info

SQL_Delay: 0

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

The key fields from the status report to examine are:

Slave_IO_State: The current status of the slave. See Section 8.14.6, "Replication Slave I Thread States", andSection 8.14.7, "Replication Slave SQL Thread States", for more information.

Slave_IO_Running: Whether the I/O thread for reading the master's binary log is running. Normally, you want this to beYes unless you have not yet started replication or have explicitly stopped it with STOP SLAVE.

Slave_SQL_Running: Whether the SQL thread for executing events in the relay log is running. As with the I/O thread, this should normally be Yes.

Last_IO_Error, Last_SQL_Error: The last errors registered by the I/O and SQL threads when processing the relay log. Ideally these should be blank, indicating no errors.

Seconds_Behind_Master: The number of seconds that the slave SQL thread is behind processing the master binary log. A high number (or an increasing one) can indicate that the slave is unable to handle events from the master in a timely fashion.

A value of 0 for Seconds_Behind_Master can usually be interpreted as meaning that the slave has caught up with the master, but there are some cases where this is not strictly true. For example, this can occur if the network connection between master and slave is broken but the slave I/O thread has not yet noticed this-that is, slave_net_timeout has not yet elapsed.

It is also possible that transient values for Seconds_Behind_Master may not reflect the situation accurately. When the slave SQL thread has caught up on I thread is still queuing up a new event O, Seconds_Behind_Master displays 0; but when the slave I Dot O thread is still queuing up a new event, Seconds_Behind_Master may show a large value until the SQL thread finishes executing the new event. This is especially likely when the events have old timestamps; in such cases, if you execute SHOW SLAVE STATUS several times in a relatively short period, you may see this value change back and forth repeatedly between 0 and a relatively large value.

Several pairs of fields provide information about the progress of the slave in reading events from the master binary log and processing them in the relay log:

(Master_Log_file, Read_Master_Log_Pos): Coordinates in the master binary log indicating how far the slave I am O thread has read events from that log.

(Relay_Master_Log_File, Exec_Master_Log_Pos): Coordinates in the master binary log indicating how far the slave SQL thread has executed events received from that log.

(Relay_Log_File, Relay_Log_Pos): Coordinates in the slave relay log indicating how far the slave SQL thread has executed the relay log. These correspond to the preceding coordinates, but are expressed in slave relay log coordinates rather than master binary log coordinates.

The SHOW STATUS statement also provides some information relating specifically to replication slaves. The replication heartbeat information displayed by SHOW STATUS lets you check that the replication connection is active even if the master has not sent events to the slave recently. The master sends a heartbeat signal to a slave if there are no updates to, and no unsent events in, the binary log for a longer period than the heartbeat interval. The MASTER_HEARTBEAT_PERIOD setting on the master (set by theCHANGE MASTER TO statement) specifies the frequency of the heartbeat, which defaults to half of the connection timeout interval for the slave (slave_net_timeout). The Slave_last_heartbeat variable for SHOW STATUS shows when the replication slave last received a heartbeat signal.

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