AWS DMS 无法正确地将文本列从本地 Postgres 加载到 Aurora Serverless

Question

我面临一个问题，我的本地数据库实例中有一堆

text

作为数据类型的列。

当我使用

dms.t3.micro

实例运行 DMS 时，文本列未正确传输。我考虑了本地部署所需的所有设置，但我想知道为什么这不起作用。

特定值的最大大小为 10 - 15kb。 在日志中我没有发现任何可疑的东西：

2023-04-07T06:57:08:287106 [TARGET_LOAD ]T: Insert row to table 'table_1' with LOB Lookup ('3' LOBs) (odbc_util.c:3874)

使用验证时，我在该表上得到

Mismatched records

，因为它们未传输。

完全加载完成后在日志中发现这一点：

2023-04-07T07:23:30:466649 [VALIDATOR       ]D:  iSourceLatency : 0, iTargetLatency : 1226882  iMigrationLatency : 2453764  (replicationtask.c:3626)

谁能给个正确的解释吗？

这是我的 DMS 设置：

    {
    "Logging": {
        "EnableLogging": true,
        "EnableLogContext": false,
        "LogComponents": [
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "TRANSFORMATION"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "SOURCE_UNLOAD"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "IO"
            },
            {
                "Severity": "LOGGER_SEVERITY_DETAILED_DEBUG",
                "Id": "TARGET_LOAD"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "PERFORMANCE"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "SOURCE_CAPTURE"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "SORTER"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "REST_SERVER"
            },
            {
                "Severity": "LOGGER_SEVERITY_DETAILED_DEBUG",
                "Id": "VALIDATOR_EXT"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "TARGET_APPLY"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "TASK_MANAGER"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "TABLES_MANAGER"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "METADATA_MANAGER"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "FILE_FACTORY"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "COMMON"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "ADDONS"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "DATA_STRUCTURE"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "COMMUNICATION"
            },
            {
                "Severity": "LOGGER_SEVERITY_DEFAULT",
                "Id": "FILE_TRANSFER"
            }
        ]
    },
    "StreamBufferSettings": {
        "StreamBufferCount": 3,
        "StreamBufferSizeInMB": 8,
        "CtrlStreamBufferSizeInMB": 5
    },
    "ErrorBehavior": {
        "FailOnNoTablesCaptured": true,
        "ApplyErrorUpdatePolicy": "LOG_ERROR",
        "FailOnTransactionConsistencyBreached": false,
        "RecoverableErrorThrottlingMax": 1800,
        "DataErrorEscalationPolicy": "SUSPEND_TABLE",
        "ApplyErrorEscalationCount": 0,
        "RecoverableErrorStopRetryAfterThrottlingMax": true,
        "RecoverableErrorThrottling": true,
        "ApplyErrorFailOnTruncationDdl": false,
        "DataTruncationErrorPolicy": "LOG_ERROR",
        "ApplyErrorInsertPolicy": "LOG_ERROR",
        "EventErrorPolicy": "IGNORE",
        "ApplyErrorEscalationPolicy": "LOG_ERROR",
        "RecoverableErrorCount": -1,
        "DataErrorEscalationCount": 0,
        "TableErrorEscalationPolicy": "STOP_TASK",
        "RecoverableErrorInterval": 5,
        "ApplyErrorDeletePolicy": "IGNORE_RECORD",
        "TableErrorEscalationCount": 0,
        "FullLoadIgnoreConflicts": true,
        "DataErrorPolicy": "LOG_ERROR",
        "TableErrorPolicy": "SUSPEND_TABLE"
    },
    "ValidationSettings": {
        "EnableValidation": false
    },
    "TTSettings": null,
    "FullLoadSettings": {
        "CreatePkAfterFullLoad": false,
        "StopTaskCachedChangesApplied": false,
        "StopTaskCachedChangesNotApplied": false,
        "MaxFullLoadSubTasks": 2,
        "TransactionConsistencyTimeout": 600,
        "CommitRate": 100,
        "TargetTablePrepMode": "DROP_AND_CREATE"
    },
    "TargetMetadata": {
        "TargetSchema": "",
        "SupportLobs": true,
        "FullLobMode": true,
        "LobChunkSize": 64,
        "LimitedSizeLobMode": false,
        "InlineLobMaxSize": 4,
        "LoadMaxFileSize": 0,
        "BatchApplyEnabled": false,
        "ParallelLoadThreads": 0,
        "ParallelLoadBufferSize": 0,
        "ParallelLoadQueuesPerThread": 0,
        "ParallelApplyThreads": 0,
        "ParallelApplyBufferSize": 0,
        "ParallelApplyQueuesPerThread": 0,
        "TaskRecoveryTableEnabled": false
    },
    "ControlTablesSettings": {
        "historyTimeslotInMinutes": 5,
        "HistoryTimeslotInMinutes": 5,
        "HistoryTableEnabled": true,
        "SuspendedTablesTableEnabled": true,
        "StatusTableEnabled": true,
        "FullLoadExceptionTableEnabled": false
    },
    "ChangeProcessingTuning": {
        "BatchApplyPreserveTransaction": true,
        "BatchApplyTimeoutMin": 1,
        "BatchApplyTimeoutMax": 30,
        "BatchApplyMemoryLimit": 500,
        "BatchSplitSize": 0,
        "MinTransactionSize": 1000,
        "CommitTimeout": 1,
        "MemoryLimitTotal": 1024,
        "MemoryKeepTime": 60,
        "StatementCacheSize": 50
    },
    "ChangeProcessingDdlHandlingPolicy": {
        "HandleSourceTableDropped": true,
        "HandleSourceTableTruncated": true,
        "HandleSourceTableAltered": true
    },
    "PostProcessingRules": null,
    "BeforeImageSettings": null,
    "LoopbackPreventionSettings": null,
    "CharacterSetSettings": null,
    "FailTaskWhenCleanTaskResourceFailed": false
}

Answer 1

我们在尝试转换 PSQL/TEXT 字段时遇到了同样的问题，导致静默失败（目标上的数据为空）。

AWS 支持指出，在撰写本文时，文档确认映射到 BLOB/CLOB 数据类型的列的唯一支持的转换是将列删除到目标上。假设

BLOB/CLOB/NCLOB

。

参见，dms 文档