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    DataWorks:FAQ about real-time data synchronization to AnalyticDB for MySQL

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    DataWorks:FAQ about real-time data synchronization to AnalyticDB for MySQL

    Last Updated:Jun 10, 2025

    The topic provides answers to some frequently asked questions about failures for real-time synchronization to AnalyticDB for MySQL V3.0.

    What do I do if the network connectivity test fails for a data source?

    • Problem description: When I add a data source to DataWorks, the network connectivity test for the data source fails.

    • Solution: Check the network connectivity configurations of the data source. For more information, see Network connectivity solutions.

    The system displays the following error message for a real-time synchronization node: "com.alibaba.otter.canal.parse.exception.PositionNotFoundException: can't find start position for XXX." What do I do?

    • Problem description: The real-time synchronization node fails to run, and the system displays the error message "com.alibaba.otter.canal.parse.exception.PositionNotFoundException: can't find start position for XXX."

    • Cause: The binary logging feature is disabled for the PolarDB data source.

    • Solution: Enable the binary logging feature for the PolarDB data source, change one or more data records, and change the start offset of the real-time synchronization node to the current time. For more information about how to enable the binary logging feature for a PolarDB data source, see Enable binary logging.

    The system displays the following error message for a real-time synchronization node: "com.alibaba.otter.canal.parse.exception.CanalParseException: command : 'show master status' has an error! pls check. you need (at least one of) the SUPER,REPLICATION CLIENT privilege(s) for this operation." What do I do?

    • Problem description: The real-time synchronization node fails to run, and the system displays the error message "com.alibaba.otter.canal.parse.exception.CanalParseException: command : 'show master status' has an error! pls check. you need (at least one of) the SUPER,REPLICATION CLIENT privilege(s) for this operation."

    • Cause: The account used to synchronize data is not authorized to access the PolarDB data source, or the PolarDB database connected is not deployed on the PolarDB Writer node.

    • Solution: Authorize the account to access the PolarDB data source by referring to Create and manage a database account, or check whether the PolarDB database connected is deployed on the PolarDB Writer node. When a real-time synchronization node is run, the system cannot capture data from the PolarDB Reader nodes of the PolarDB cluster.

    The system displays the following error message for a real-time synchronization node: "com.alibaba.datax.plugin.reader.mysqlbinlogreader.MysqlBinlogReaderException: The mysql server does not enable the binlog write function. Please enable the mysql binlog write function first." What do I do?

    • Problem description: The real-time synchronization node fails to run, and the system displays the error message "com.alibaba.datax.plugin.reader.mysqlbinlogreader.MysqlBinlogReaderException: The mysql server does not enable the binlog write function. Please enable the mysql binlog write function first."

    • Cause: The loose_polar_log_bin parameter is not specified for the PolarDB data source.

    • Solution: Specify the loose_polar_log_bin parameter. For more information, see Configure cluster and node parameters.

    The system displays the following error message for a real-time synchronization node: MongoDBReader$Task - operation exceeded time limitcom.mongodb.MongoExecutionTimeoutException: operation exceeded time limit. What do I do?

    • Problem description: When the real-time synchronization node is run, an error occurs and the system displays the following error message: MongoDBReader$Task - operation exceeded time limitcom.mongodb.MongoExecutionTimeoutException: operation exceeded time limit.

    • Cause: The amount of data that you want to synchronize is excessively large.

    • Solutions:

      • Increase the number of parallel threads for the node.

      • Reduce the value of the BatcSsize parameter.

      • Add the cursorTimeoutInMs parameter to the configurations of the Reader plug-in and specify a large value for this parameter, such as 3600000s.