mysql dump binlog master状态

遇到个dump binlog延迟增加的问题，发现master上的dump线程状态多数时间是 

 Finished reading one binlog; switching to next binlog

 查问题要看系统IO，可能是dump程序太多，导致IO繁忙；

 dba反馈load 8，iowait和ioutil并不高；但是业务在跑定时任务，导致tps很高，tps高会导致dump 变慢？这个之前没有遇到过

 mysql> show processlist;
 +----------+---------+----------------------+------+-------------+---------+-------------------------------------------------------+------------------+-----------+---------------+-----------+
 | Id       | User    | Host                 | db   | Command     | Time    | State                                                 | Info             | Rows_sent | Rows_examined | Rows_read |
 +----------+---------+----------------------+------+-------------+---------+-------------------------------------------------------+------------------+-----------+---------------+-----------+
 | 18618377 | jw_sync | 172.20.136.45:58226  | NULL | Binlog Dump | 1724575 | Finished reading one binlog; switching to next binlog | NULL             |         0 |             0 |       198 |
 | 18618389 | jw_sync | 172.20.150.87:58321  | NULL | Binlog Dump | 1724572 | Finished reading one binlog; switching to next binlog | NULL             |         0 |             0 |       198 |
 | 18618665 | jw_sync | 172.20.148.70:37864  | NULL | Binlog Dump | 1724438 | Finished reading one binlog; switching to next binlog | NULL             |         0 |             0 |       198 |
 | 21133727 | jw_sync | 172.20.133.18:56499  | NULL | Binlog Dump |  578883 | Finished reading one binlog; switching to next binlog | NULL             |         0 |             0 |       198 |
 | 22466211 | jw_sync | 172.23.227.174:60700 | NULL | Query       |       0 | NULL                                                  | show processlist |         0 |             0 |         2 |
 +----------+---------+----------------------+------+-------------+---------+-------------------------------------------------------+------------------+-----------+---------------+

Binlog Dump 状态一共4个

1 Sending binlog event to slave

已经读出来，正在发送

2 Finished reading one binlog; switching to next binlog

The thread has finished reading a binary log file and is opening the next one to send to the slave.

3 Master has sent all binlog to slave; waiting for binlog to be updated

等着新的binlog产生

4 Waiting to finalize termination

线程停止时候一个短暂状态