在使用canal同步mysql数据的时候出现Could not find first log file name in binary log index file无法找到binlog文件的问题，详细错误如下
java.io.IOException: Received error packet: errno = 1236, sqlstate = HY000 errmsg = Could not find first log file name in binary log index file
at com.alibaba.otter.canal.parse.inbound.mysql.dbsync.DirectLogFetcher.fetch(DirectLogFetcher.java:102) ~[canal.parse-1.1.6.jar:na]
at com.alibaba.otter.canal.parse.inbound.mysql.MysqlConnection.dump(MysqlConnection.java:237) [canal.parse-1.1.6.jar:na]
at com.alibaba.otter.canal.parse.inbound.AbstractEventParser$1.run(AbstractEventParser.java:262) [canal.parse-1.1.6.jar:na]
at java.lang.Thread.run(Thread.java:750) [na:1.8.0_333]
java.io.IOException: Received error packet: errno = 1236, sqlstate = HY000 errmsg = Could not find first log file name in binary log index file
at com.alibaba.otter.canal.parse.inbound.mysql.dbsync.DirectLogFetcher.fetch(DirectLogFetcher.java:102) ~[canal.parse-1.1.6.jar:na]
at com.alibaba.otter.canal.parse.inbound.mysql.MysqlConnection.dump(MysqlConnection.java:237) ~[canal.parse-1.1.6.jar:na]
at com.alibaba.otter.canal.parse.inbound.AbstractEventParser$1.run(AbstractEventParser.java:262) ~[canal.parse-1.1.6.jar:na]
at java.lang.Thread.run(Thread.java:750) [na:1.8.0_333]
ERROR com.alibaba.otter.canal.common.alarm.LogAlarmHandler - destination:example[java.io.IOException: Received error packet: err
no = 1236, sqlstate = HY000 errmsg = Could not find first log file name in binary log index file
at com.alibaba.otter.canal.parse.inbound.mysql.dbsync.DirectLogFetcher.fetch(DirectLogFetcher.java:102)
at com.alibaba.otter.canal.parse.inbound.mysql.MysqlConnection.dump(MysqlConnection.java:237)
at com.alibaba.otter.canal.parse.inbound.AbstractEventParser$1.run(AbstractEventParser.java:262)
at java.lang.Thread.run(Thread.java:750)
]
此问题主要是因为logfile被覆盖导致，可以在canal/conf/example下查看meta.dat文件检查当前读取的binlog文件位置
"postion":{"gtid":"","included":false,"journalName":"mys
ql-bin.000591","position":25928,"serverId":21381487,"timestamp":1663232397000}}}],"destination":"example"}[root@iZ2vcfjagtpbh97ar0zj6cZ example]
然后对比当前MySQL的binlog文件和position
在MySQL中使用show master status查看
解决方案：
1、先停止canal server
2、删除canal/conf/example/meta.dat
3、更新canal/conf/example/instance.properties文件中
canal.instance.master.journal.name=xxx
canal.instance.master.position=xxx
这两个字段，分别对应当前数据库中的file和position
4、重启canal server
然后可以查看canal/logs/example/example.log检查是否还存在找不到binlog文件问题
