189 8069 5689
现象说明：老数据库版本是5.6,新库版本5.7，数据量不大，备份恢复数据均正常，配置主从使用gtid复制后也是正常的，第二天查看新库的时候，发现新库复制出现问题，报错如下:
2019-10-10T10:15:27.541697+08:00 4256 [Warning] Master server does not support semi-sync, fallback to asynchronous replication
2019-10-10T10:15:29.993985+08:00 4257 [ERROR] Transaction is tagged with inconsistent logical timestamps: sequence_number (3546074770274598260) <= last_committed (8314045271803935669)
2019-10-10T10:15:29.994028+08:00 4257 [Warning] Slave SQL for channel '': Coordinator thread of multi-threaded slave is being stopped in the middle of assigning a group of events; deferring to exit until the group completion ... , Error_code: 0
2019-10-10T10:15:29.994052+08:00 4257 [ERROR] Slave SQL for channel '': Cannot execute the current event group in the parallel mode. Encountered event Gtid, relay-log name ./relay.000002, position 1090573 which prevents execution of this event group in parallel mode. Reason: The master event is logically timestamped incorrectly.. Error_code: 1755
2019-10-10T10:15:29.994066+08:00 4257 [Warning] Slave: Cannot execute the current event group in the parallel mode. Encountered event Gtid, relay-log name ./relay.000002, position 1090573 which prevents execution of this event group in parallel mode. Reason: The master event is logically timestamped incorrectly.. Error_code: 1755
2019-10-10T10:15:29.994070+08:00 4257 [ERROR] Error running query, slave SQL thread aborted. Fix the problem, and restart the slave SQL thread with "SLAVE START". We stopped at log 'logbin.000015' position 234960156
2019-10-10T10:16:01.494097+08:00 4256 [Note] Slave I/O thread killed while reading event for channel ''
查看数据库的变量参数 slave_parallel_workers ,发现老库的是0，串行复制，新库的是4，并行组复制，根据网上查到的内容，也是由于这个参数导致
修复方法：修改新库的slave_parallel_workers 参数为0，清理数据库，清理binlog 日志，恢复数据，重建主从关系，主从复制OK
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