HA模式下，canal.instance.tsdb.enable=true，数据库进行主从切换后，canal的master与standby 切换后，会报如下异常。目前我使用的解决方式是将canal.instance.tsdb.enable=false，就可以进行正常的切换了。

2018-08-07 10:44:48.772 [destination = orderfailover , address = /10.8.132.135:3306 , EventParser] WARN c.a.otter.canal.parse.inbound.mysql.MysqlEventParser - prepare to find start position by switch ::1532919362000
2018-08-07 10:44:48.780 [destination = orderfailover , address = /10.8.132.135:3306 , EventParser] WARN c.a.otter.canal.parse.inbound.mysql.MysqlEventParser - Didn't find the corresponding binlog files from mysql-bin.000020 to mysql-bin.000021
2018-08-07 10:44:48.782 [destination = orderfailover , address = /10.8.132.135:3306 , EventParser] ERROR c.a.otter.canal.parse.inbound.mysql.MysqlEventParser - dump address /10.8.132.135:3306 has an error, retrying. caused by
com.alibaba.otter.canal.parse.exception.CanalParseException: can't find start position for orderfailover
2018-08-07 10:44:48.782 [Druid-ConnectionPool-Create-1877078260] ERROR com.alibaba.druid.pool.DruidDataSource - create connection SQLException, url: , errorCode 0, state null
java.sql.SQLException: connect error, url , driverClass org.h2.Driver
at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1582) ~[druid-1.1.9.jar:1.1.9]
at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:2466) ~[druid-1.1.9.jar:1.1.9]
2018-08-07 10:44:48.782 [destination = orderfailover , address = /10.8.132.135:3306 , EventParser] ERROR com.alibaba.otter.canal.common.alarm.LogAlarmHandler - destination:orderfailover[com.alibaba.otter.canal.parse.exception.CanalParseException: can't find start position for orderfailover
]
2018-08-07 10:44:49.282 [Druid-ConnectionPool-Create-1877078260] ERROR com.alibaba.druid.pool.DruidDataSource - create connection SQLException, url: , errorCode 0, state null
java.sql.SQLException: connect error, url , driverClass org.h2.Driver
at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1582) ~[druid-1.1.9.jar:1.1.9]
at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:2466) ~[druid-1.1.9.jar:1.1.9]
2018-08-07 10:44:49.783 [Druid-ConnectionPool-Create-1877078260] ERROR com.alibaba.druid.pool.DruidDataSource - create connection SQLException, url: , errorCode 0, state null
java.sql.SQLException: connect error, url , driverClass org.h2.Driver
at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1582) ~[druid-1.1.9.jar:1.1.9]
at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:2466) ~[druid-1.1.9.jar:1.1.9]
2018-08-07 10:44:50.283 [Druid-ConnectionPool-Create-1877078260] ERROR com.alibaba.druid.pool.DruidDataSource - create connection SQLException, url: , errorCode 0, state null
java.sql.SQLException: connect error, url , driverClass org.h2.Driver
at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1582) ~[druid-1.1.9.jar:1.1.9]
at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:2466) ~[druid-1.1.9.jar:1.1.9]
2018-08-07 10:44:50.783 [Druid-ConnectionPool-Create-1877078260] ERROR com.alibaba.druid.pool.DruidDataSource - create connection SQLException, url: , errorCode 0, state null
java.sql.SQLException: connect error, url , driverClass org.h2.Driver
at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1582) ~[druid-1.1.9.jar:1.1.9]
at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:2466) ~[druid-1.1.9.jar:1.1.9]
2018-08-07 10:44:51.283 [Druid-ConnectionPool-Create-1877078260] ERROR com.alibaba.druid.pool.DruidDataSource - create connection SQLException, url: , errorCode 0, state null