MySQL 5.6 master-slave replication Part 4 [some ignored Operation Details]

MySQL 5.6 master-slave replication Part 4 [some ignored Operation Details]

1. STOP SLAVE
 
There are two types of threads responsible for synchronization from the server:
1) IO thread
2) SQL thread
 
IO thread is responsible for obtaining binary logs on the master and executing Multiple SQL threads.
 
IO thread determines Retrieved_Gtid_Set
SQL thread determines Executed_Gtid_Set
 
Since IO thread is prior to SQL thread, Retrieved_Gtid_Set may be slightly more than Executed_Gtid_Set.
For example:

 

Mysql [localhost] {msandbox} (test)> SHOW slave STATUS \ G
.......
.......
Retrieved_Gtid_Set: 67cd9435-7cae-11e2-aa8d-00241db92e69: 1-9
Executed_Gtid_Set: 67cd9435-7cae-11e2-aa8d-00241db92e69: 1-7
Auto_Position: 1

Therefore, when stopping slave, the correct operation is:
1) stop slave io_thread;
2) show slave status: Make sure Executed_Gtid_Set has caught up with Retrieved_Gtid_Set.
3) stop slave SQL _thread.
 
2. flush tables with read lock and show slave status
 
Open a session 1 on a fully normal slave server:
Mysql> flush tables with read lock;
If the master server is updated,
Run another session2 on the server:
Mysql> show slave status will be stuck until the unlock tables is executed in session1.
 
If show slave status is also executed in session 1, it cannot be recovered ....
 
Mysql [localhost] {msandbox} (test)> flush tables with read lock;
Query OK, 0 rows affected (0.01 sec)
// The master server is updated.
Mysql [localhost] {msandbox} (test)> show slave status;
Stuck here...
Of course, ctrl + c can be canceled,
 
Ctrl-C-sending "kill query 1" to server...
Ctrl-C-query aborted.
Ctrl-C-sending "KILL 1" to server...
Ctrl-C-query aborted.
ERROR 2013 (HY000): Lost connection to MySQL server during query
Mysql [localhost] {msandbox} (test)>
It is useless even if you unlock tables .. The connection has been disconnected ..
Mysql [localhost] {msandbox} (test)> unlock tables;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 14
Current database: test
 
Query OK, 0 rows affected (0.01 sec)
 
And now mysqld cannot stop...
[Modify @ H209 msb_5_6_10_ B] $./stop
Warning; Aborted waiting on pid file: '/home/modify/sandboxes/msb_5_6_10_ B/data/mysql_sandbox5612.pid' after 190 seconds
Attempting normal termination-kill-15 10858
 
So before flush tables with read lock, stop slave...
 
Http://bugs.mysql.com /? Id = 68460

MySQL 5.6 master-slave replication Part 1 [Introduction and configuration]

MySQL 5.6 master-slave replication Part 2 [restore an slave server]

MySQL 5.6 master-slave replication Part 3 [upgrade slave server to master server]

MySQL 5.6 master-slave replication Part 4 [some ignored Operation Details]

MySQL master-slave Replication Event validation MySQL Replication Event Checksum

Use pt-table-checksum to check whether master-slave replication is normal