Error number: 4047; Symbol: ER_WARN_SQL_AFTER_MTS_GAPS_GAP_NOT_CALCULATED; SQLSTATE: HY000
Message: The until clause SQL_AFTER_MTS_GAPS is being used for channel ‘%s’ when GTID_MODE = ON and SOURCE_AUTO_POSITION=1 meaning the server did not compute internally what gaps may exist in the relay log transaction execution. To close any execution gaps use either the SQL_BEFORE_GTIDS or SQL_AFTER_GTIDS until clause.
Error 4047, labelled as ER_WARN_SQL_AFTER_MTS_GAPS_GAP_NOT_CALCULATED, is a MySQL error that appears when a MySQL replication gap exists when using a Master-to-Slave Multi-Source replication setup.
错误4047标记为ER_WARN_SQL_AFTER_MTS_GAPS_GAP_NOT_CALCULATED，是MySQL的一个错误，当使用主从多源复制设置时出现MySQL复制间隙时出现。
Error 4047 occurs when replicas do not keep up with the Master server when there are multiple transactions at once. This may occur when the replicas lag behind or when conflicts arise. When this error occurs, MySQL attempts to insert rows in the replica that it missed; however, it can’t insert them whether because the row was already taken in by the replica or the row was changed externally.
Error 4047发生在复制从服务器未能跟上主服务器的变化，当多个事务同时发生时它就会出现。这可能是因为复制从服务器落后或者发生冲突。当此错误发生时，MySQL会尝试将错过的行插入到复制从服务器中；然而，由于行已被复制从服务器接管或行已经被外部改变，它无法将其插入。
Common cases for Error 4047 include replicas failing to connect, conflicts existing between replicas and the Master server, and a replica taking extra time to process a transaction.
The recommended action for troubleshooting Error 4047 is to identify the source of the errors and then try to replicate the errors on the Master server. It’s important to note that some of the solutions require enabling binlogging on slave configurations. Once the underlying problem is found, the solutions can vary.
解决Error4047的建议行动是识别错误来源，然后在主服务器上尝试复制错误。重要的是要注意，有些解决方案需要在从设置中启用binlogging。一旦发现了根本问题，解决方案就会变得各不相同。
For instance, one potential solution involves disabling the parallel replication option by setting the value to zero. If the replica continues to experience issues with latency or crashes, you may need to investigate the server load and make the necessary changes to ensure optimal replication performance. Additionally, you might have to identify and rectify any issues with transaction conflicts.
例如，一个潜在的解决方案包括通过将值设置为零来禁用并行复制选项。如果复制从服务器继续遇到延迟问题或崩溃问题，则可能需要调查服务器负载并进行必要的更改，以确保最佳复制性能。此外，您可能还需要识别并纠正任何事务冲突问题。
In some cases, you may have to stop replication altogether and initiate a new replication process from scratch. This should be done only if the source cause cannot be identified or if the other solutions are not working to fix the issue.
在某些情况下，您可能必须完全停止复制并从头开始新的复制过程。只有在无法识别源原因或其他解决方案无法解决问题时，才应该这样做。