今天搭建mysql 主从队列，延迟时间比较长
Seconds_Behind_Master: 47776
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: 1000
Master_UUID: 74d738a1-b62f-11e8-86a7-a0369ff53354
Master_Info_File: mysql.slave_master_info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Waiting for dependent transaction to commit
Master_Retry_Count: 86400
通过监控日志发现了很长的note 记录一下：
2018-09-13T02:41:26.069970Z 25 [Note] Multi-threaded slave statistics for channel '': seconds elapsed = 252; events assigned = 1025; worker queues filled over overrun level = 0; waited due a Worker queue full = 0; waited due the total size = 0; waited at clock conflicts = 11582222100 waited (count) when Workers occupied = 0 waited when Workers occupied = 0
2018-09-13T02:43:26.738761Z 25 [Note] Multi-threaded slave statistics for channel '': seconds elapsed = 120; events assigned = 73729; worker queues filled over overrun level = 0; waited due a Worker queue full = 0; waited due the total size = 0; waited at clock conflicts = 130894105700 waited (count) when Workers occupied = 5 waited when Workers occupied = 131145300
2018-09-13T02:45:26.230192Z 25 [Note] Multi-threaded slave statistics for channel '': seconds elapsed = 120; events assigned = 179201; worker queues filled over overrun level = 0; waited due a Worker queue full = 0; waited due the total size = 0; waited at clock conflicts = 248748357600 waited (count) when Workers occupied = 5 waited when Workers occupied = 131145300
2018-09-13T02:47:29.039700Z 25 [Note] Multi-threaded slave statistics for channel '': seconds elapsed = 123; events assigned = 280577; worker queues filled over overrun level = 0; waited due a Worker queue full = 0; waited due the total size = 0; waited at clock conflicts = 369673169800 waited (count) when Workers occupied = 5 waited when Workers occupied = 131145300
2018-09-13T02:49:33.520110Z 25 [Note] Multi-threaded slave statistics for channel '': seconds elapsed = 124; events assigned = 449537; worker queues filled over overrun level = 0; waited due a Worker queue full = 0; waited due the total size = 0; waited at clock conflicts = 491909458900 waited (count) when Workers occupied = 10 waited when Workers occupied = 136565800
SLAVE多线程同步的信息
seconds elapsed 就是上一次统计跟这一次统计的时间间隔
events assigned：总共有多少个event被分配执行，计的是总数。
worker queues filled over overrun level：多线程同步中，worker 的私有队列长度超长的次数，计的是总数。
waited due a Worker queue full ：因为worker的队列超长而产生等待的次数，计的是总数。
waited due the total size ：超过最大size的次数，这个由参数slave_pending_jobs_size_max 指定。
waited at clock conflicts ：因为逻辑时间产生冲突的等待时间，单位是纳秒。
waited (count) when Workers occupied ：因为workder被占用而出现等待的次数。（总计值）。
waited when Workersoccupied ：因为workder被占用而出现等待的总时间，总计值，单位是纳秒。