在使用mysql5.7的时候，发现了不少在mysql5.6上不曾见过的日志，级别为note, 最常见的note日志以下三种，下面我们来逐个解释。
第一种，Aborted connection . 如上图，信息如下：
2020-08-17T14:44:24.102542Z 59 [Note] Aborted connection 59 to db: ‘unconnected’ user: ‘mha’ host: ‘10.xx.xx.xx’ (Got an error reading communication packets)
2020-08-17T14:44:31.273897Z 61 [Note] Aborted connection 61 to db: ‘unconnected’ user: ‘mha’ host: ‘10.xx.xx.xx(Got an error reading communication packets)
2020-08-17T14:44:31.273897Z 61 [Note] Aborted connection 61 to db: ‘unconnected’ user: ‘mha’ host: ‘10.xx.xx.xx(Got an error reading communication packets)
2020-08-17T14:44:31.273897Z 61 [Note] Aborted connection 61 to db: ‘unconnected’ user: ‘mha’ host: ‘10.xx.xx.xx(Got timeout reading communication packets)
上面两个是连接中断的错误信息，原因不一样，
Got an error reading communication packets 的原因是因为网络等原因导致。
Got timeout reading communication packets 这个错误的原因是会话的idle时间达到了数据库指定的timeout时间。