In the master-slave replication, there are several parameters is very important to include slave_net_timeout, MASTER_HEARTBEAT_PERIOD, MASTER_CONNECT_RETRY, and MASTER_RETRY_COUNT.
It represents slave_net_timeout master slave has not received any data (including binlog, heartbeat) within slave_net_timeout of time, that slave disconnected, needs to reconnect. The default value is 60s.
MASTER_HEARTBEAT_PERIOD represents a period heartbeat. When the MASTER_HEARTBEAT_PERIOD of time, no Master binlog event sent to the slave when the slave sends data to the heartbeat.
MASTER_CONNECT_RETRY represents reconnection interval.
After slave_net_timeout timeout reconnection immediately subsequent reconnection interval MASTER_CONNECT_RETRY by the CHANGE MASTER TO command parameters specified. The default value is 60s.MASTER_CONNECT_RETRY represents the maximum number of reconnection. The default value is 86400 times.
View and set the 1.slave_net_timeout
View slave_net_timeout can use the following ways:
mysql> select @@global.slave_net_timeout;
+----------------------------+
| @@global.slave_net_timeout |
+----------------------------+
| 60 |
+----------------------------+
1 row in set (0.00 sec)or
mysql> show variables like 'slave_net_timeout';
+-------------------+-------+
| Variable_name | Value |
+-------------------+-------+
| slave_net_timeout | 50 |
+-------------------+-------+
1 row in set (0.00 sec)Set slave_net_timeout:
mysql> set global slave_net_timeout=50;
Query OK, 0 rows affected (0.00 sec)
mysql> show variables like 'slave_net_timeout';
+-------------------+-------+
| Variable_name | Value |
+-------------------+-------+
| slave_net_timeout | 50 |
+-------------------+-------+
1 row in set (0.00 sec)2.MASTER_HEARTBEAT_PERIOD, MASTER_CONNECT_RETRY,以及 MASTER_RETRY_COUNT
Set 2.1
MASTER_HEARTBEAT_PERIOD
MASTER_HEARTBEAT_PERIOD to command set by the change master.
with no change master to heartbeat parameters, the default is set to half of slave_net_timeoute. When slave_net_timeoute change, does not modify the heartbeat.
MASTER_RETRY_COUNT
MASTER_RETRY_COUNT through the command line parameter --master-retry-count settings can also be set by change master to fashion.
The former is not recommended, encourage the use of change master to.
MASTER_CONNECT_RETRY
MASTER_CONNECT_RETRY to command set by the change master.
2.2 View
Execution show slave status from the library, you can view Master_Retry_Count, Connect_Retry, as well as more master copy from the storage location information Master_Info_File.
>show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: xr-dba-mysql-hazyytest-test01
Master_User: XXXX
Master_Port: 5002
Connect_Retry: 10
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 488
Relay_Log_File: relay.000002
Relay_Log_Pos: 698
Relay_Master_Log_File: mysql-bin.000001
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: 488
Relay_Log_Space: 892
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: 48201050
Master_UUID: 10035945-ddeb-11e9-89f3-0022ac533a2f
Master_Info_File: mysql.slave_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: 10035945-ddeb-11e9-89f3-0022ac533a2f:1-2
Executed_Gtid_Set: 10035945-ddeb-11e9-89f3-0022ac533a2f:1-2
Auto_Position: 1
1 row in set (0.00 sec)Can be seen from the above results, Master_Info_File stored in the data tables:
Master_Info_File: mysql.slave_master_info.
Then by querying the data table to see these parameters:
>select * from mysql.slave_master_info\G
*************************** 1. row ***************************
Number_of_lines: 23
Master_log_name: mysql-bin.000001
Master_log_pos: 488
Host: xr-dba-mysql-hazyytest-test01
User_name: XXX
User_password: XXXX
Port: 5002
Connect_retry: 10
Enabled_ssl: 0
Ssl_ca:
Ssl_capath:
Ssl_cert:
Ssl_cipher:
Ssl_key:
Ssl_verify_server_cert: 0
Heartbeat: 8
Bind:
Ignored_server_ids: 0
Uuid: 10035945-ddeb-11e9-89f3-0022ac533a2f
Retry_count: 86400
Ssl_crl:
Ssl_crlpath:
Enabled_auto_position: 1
1 row in set (0.00 sec)Here, Connect_retry to 10, Heartbeat to 8, Retry_count 86400.
>select Connect_retry,Heartbeat, Retry_count from mysql.slave_master_info;
+---------------+-----------+-------------+
| Connect_retry | Heartbeat | Retry_count |
+---------------+-----------+-------------+
| 10 | 8 | 86400 |
+---------------+-----------+-------------+
1 row in set (0.00 sec)In addition, these parameters are configured in executing a query command from the main library on the library, the result is empty.
>select Connect_retry,Heartbeat, Retry_count from mysql.slave_master_info;
Empty set (0.00 sec)In MySQL5.7 version, you can also view these parameters in replication-connection-configuration-table in.
> select * from performance_schema.replication_connection_configuration\G
*************************** 1. row ***************************
CHANNEL_NAME:
HOST: 10.23.66.88
PORT: 5002
USER: repl
NETWORK_INTERFACE:
AUTO_POSITION: 1
SSL_ALLOWED: NO
SSL_CA_FILE:
SSL_CA_PATH:
SSL_CERTIFICATE:
SSL_CIPHER:
SSL_KEY:
SSL_VERIFY_SERVER_CERTIFICATE: NO
SSL_CRL_FILE:
SSL_CRL_PATH:
CONNECTION_RETRY_INTERVAL: 60
CONNECTION_RETRY_COUNT: 86400
HEARTBEAT_INTERVAL: 60.000
TLS_VERSION:
1 row in set (0.01 sec)