MySQL主从管理的系统视图

在上一篇博客中我们进行了基于日志点的主从复制配置，现在我们来看一下MySQL主从管理过程中MySQL是如何进行操作的，以及涉及到的相关内容；

查看表performance_schema的内容

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| softcentric        |
| sys                |
+--------------------+
5 rows in set (0.00 sec)

mysql> use performance_schema;
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> show tables;
+------------------------------------------------------+
| Tables_in_performance_schema                         |
+------------------------------------------------------+
| accounts                                             |
| cond_instances                                       |
| events_stages_current                                |
| events_stages_history                                |
| events_stages_history_long                           |
| events_stages_summary_by_account_by_event_name       |
| events_stages_summary_by_host_by_event_name          |
| events_stages_summary_by_thread_by_event_name        |
| events_stages_summary_by_user_by_event_name          |
| events_stages_summary_global_by_event_name           |
| events_statements_current                            |
| events_statements_history                            |
| events_statements_history_long                       |
| events_statements_summary_by_account_by_event_name   |
| events_statements_summary_by_digest                  |
| events_statements_summary_by_host_by_event_name      |
| events_statements_summary_by_program                 |
| events_statements_summary_by_thread_by_event_name    |
| events_statements_summary_by_user_by_event_name      |
| events_statements_summary_global_by_event_name       |
| events_transactions_current                          |
| events_transactions_history                          |
| events_transactions_history_long                     |
| events_transactions_summary_by_account_by_event_name |
| events_transactions_summary_by_host_by_event_name    |
| events_transactions_summary_by_thread_by_event_name  |
| events_transactions_summary_by_user_by_event_name    |
| events_transactions_summary_global_by_event_name     |
| events_waits_current                                 |
| events_waits_history                                 |
| events_waits_history_long                            |
| events_waits_summary_by_account_by_event_name        |
| events_waits_summary_by_host_by_event_name           |
| events_waits_summary_by_instance                     |
| events_waits_summary_by_thread_by_event_name         |
| events_waits_summary_by_user_by_event_name           |
| events_waits_summary_global_by_event_name            |
| file_instances                                       |
| file_summary_by_event_name                           |
| file_summary_by_instance                             |
| global_status                                        |
| global_variables                                     |
| host_cache                                           |
| hosts                                                |
| memory_summary_by_account_by_event_name              |
| memory_summary_by_host_by_event_name                 |
| memory_summary_by_thread_by_event_name               |
| memory_summary_by_user_by_event_name                 |
| memory_summary_global_by_event_name                  |
| metadata_locks                                       |
| mutex_instances                                      |
| objects_summary_global_by_type                       |
| performance_timers                                   |
| prepared_statements_instances                        |
| replication_applier_configuration                    |
| replication_applier_status                           |
| replication_applier_status_by_coordinator            |
| replication_applier_status_by_worker                 |
| replication_connection_configuration                 |
| replication_connection_status                        |
| replication_group_member_stats                       |
| replication_group_members                            |
| rwlock_instances                                     |
| session_account_connect_attrs                        |
| session_connect_attrs                                |
| session_status                                       |
| session_variables                                    |
| setup_actors                                         |
| setup_consumers                                      |
| setup_instruments                                    |
| setup_objects                                        |
| setup_timers                                         |
| socket_instances                                     |
| socket_summary_by_event_name                         |
| socket_summary_by_instance                           |
| status_by_account                                    |
| status_by_host                                       |
| status_by_thread                                     |
| status_by_user                                       |
| table_handles                                        |
| table_io_waits_summary_by_index_usage                |
| table_io_waits_summary_by_table                      |
| table_lock_waits_summary_by_table                    |
| threads                                              |
| user_variables_by_thread                             |
| users                                                |
| variables_by_thread                                  |
+------------------------------------------------------+
87 rows in set (0.00 sec)

以replication开头的表都是我们进行主从管理的系统视图；

• 表replication_applier_configuration 的内容

mysql> select * from replication_applier_configuration;
+--------------+---------------+
| CHANNEL_NAME | DESIRED_DELAY |
+--------------+---------------+
|              |             0 |
+--------------+---------------+
1 row in set (0.00 sec)
链路名称            主从延迟

链路名称用来在多链路复制时区分不同的链路；
主从延迟用来设置复制过程中设置的主动延迟；

mysql> change master to master_delay=3600;  #设置主动延迟

• 表replication_applier_status的内容
  mysql> select * from replication_applier_status;
+--------------+---------------+-----------------+----------------------------+
| CHANNEL_NAME | SERVICE_STATE | REMAINING_DELAY | COUNT_TRANSACTIONS_RETRIES |
+--------------+---------------+-----------------+----------------------------+
| | ON | NULL | 0 |
+--------------+---------------+-----------------+----------------------------+
1 row in set (0.00 sec)

  REMAINING_DELAY 是设置的主动延迟的时间；

• 表replication_applier_status_by_coordinator
  表示多线程复制是控制器的情况

• replication_applier_status_by_worker 多线程复制时的线程
  mysql> select * from replication_applier_status_by_worker;
+--------------+-----------+-----------+---------------+-----------------------+-------------------+--------------------+----------------------+
| CHANNEL_NAME | WORKER_ID | THREAD_ID | SERVICE_STATE | LAST_SEEN_TRANSACTION | LAST_ERROR_NUMBER | LAST_ERROR_MESSAGE | LAST_ERROR_TIMESTAMP |
+--------------+-----------+-----------+---------------+-----------------------+-------------------+--------------------+----------------------+
| | 0 | 35 | ON | ANONYMOUS | 0 | | 0000-00-00 00:00:00 |
+--------------+-----------+-----------+---------------+-----------------------+-------------------+--------------------+----------------------+
1 row in set (0.00 sec)

  上面只有一行数据，就是说只有一个线程在工作；

• replication_connection_configuration

• replication_connection_configuration
• replication_connection_status
• replication_group_member_stats
• replication_group_members